JP2008181073A - Light source device, illumination device, monitor device, and projector - Google Patents

Abstract

A light source device capable of realizing high wavelength conversion efficiency with a simple and small configuration is provided.
A semiconductor element that is a light source unit that emits light of a first wavelength, an SHG element that is a wavelength conversion element that converts light of a first wavelength into light of a second wavelength, and the light emitted from the wavelength conversion element. The second resonator 17 transmits the second wavelength light and travels to the emission destination, reflects the first wavelength light and resonates with the light source unit, and the first wavelength light and the second wavelength light. A wavelength separation film 14 that is a wavelength separation unit that separates the light, and an optical prism 13 that is a folding unit that folds the light of the second wavelength separated by the wavelength separation unit in the direction of the emission destination. The unit reflects the light having the first wavelength from the light source unit and advances the light toward the wavelength conversion element.
[Selection] Figure 1

Description

  The present invention relates to a light source device, an illumination device, a monitor device, and a projector, and more particularly to a technology of a light source device using a wavelength conversion element.

  In recent years, a technique using a laser light source that supplies laser light has been proposed as a light source device for a monitor device or a projector. Compared with a UHP lamp conventionally used as a light source device for a monitor or projector, a laser light source has advantages such as high color reproducibility, instant lighting, and long life. Known laser light sources include those that directly supply the fundamental light from the light emitting section and those that convert the wavelength of the fundamental light and supply it. As a wavelength conversion element that converts the wavelength of the fundamental wave light, for example, a second-harmonic generation (SHG) element is used. By using the wavelength conversion element, it is possible to supply laser light having a desired wavelength using a general-purpose laser light source that can be easily obtained. Further, a configuration capable of supplying a sufficient amount of laser light can also be employed. It is known that the wavelength conversion efficiency for incident light incident on the SHG element is generally about 30 to 40%. When the fundamental light is simply made incident on the SHG element, the intensity of the harmonic light that has been wavelength-converted by the SHG element becomes very small relative to the output of the fundamental light. For example, Patent Document 1 proposes a technique for supplying laser light that has been wavelength-converted with high efficiency. In the technique proposed in Patent Document 1, the fundamental light is separated from the light transmitted through the SHG element, and is incident on the SHG element again.

JP 59-128525 A

  In the case of the configuration proposed in Patent Document 1, the light whose wavelength has been converted by the SHG element is combined with the light whose wavelength has been converted by making the fundamental light once transmitted through the SHG element enter the SHG element again. In addition, a complicated and large-scale configuration is required. Moreover, the light loss increases by making light incident on many optical elements. Other configurations conventionally proposed, for example, a configuration in which light is separated using a switch structure disposed inside the resonator (see Japanese Patent Laid-Open No. 7-86668), and a mirror disposed inside the resonator are used. The configuration for separating light (see US Pat. No. 5,761,227) can be said to be the same as the configuration of Patent Document 1 with regard to the complexity and size of the configuration and the loss of light. Thus, according to the conventional technology, there arises a problem that it is difficult to realize high wavelength conversion efficiency with a simple and small configuration. The present invention has been made in view of the above-described problems, and is a light source device capable of realizing high wavelength conversion efficiency with a simple and small configuration, an illumination device using the light source device, a monitor device using the illumination device, and a projector. The purpose is to provide.

  In order to solve the above-described problems and achieve the object, according to the present invention, a light source unit that emits light having a first wavelength, light having a first wavelength, and light having a second wavelength different from the first wavelength. A wavelength conversion element that converts light to a wavelength conversion element and an external resonator that transmits light of a second wavelength emitted from the wavelength conversion element and travels to the emission destination, reflects light of the first wavelength, and resonates with the light source unit And transmitting the light converted from the first wavelength to the second wavelength and reflecting the light of the first wavelength in the process of traveling from the external resonator to the light source unit, and thereby reflecting the light of the first wavelength and the second wavelength. A wavelength separation unit that separates the light of the first wavelength, and a folding unit that folds back the light of the second wavelength separated by the wavelength separation unit in the direction of the emission destination. The wavelength separation unit is a first wavelength from the light source unit. A light source device that reflects the light of the light and travels in the direction of the wavelength conversion element Door can be.

  The light converted from the first wavelength to the second wavelength in the process of traveling from the light source unit to the external resonator passes through the external resonator. The light having the first wavelength in the process of traveling from the light source unit to the external resonator is reflected by the external resonator and enters the wavelength conversion element. The light converted from the first wavelength to the second wavelength in the process of traveling from the external resonator to the light source unit passes through the wavelength separation unit and then enters the folding unit. The second wavelength light incident on the folded portion is guided in the direction of the emission destination. In this manner, light converted from the first wavelength to the second wavelength in the process of traveling from the light source unit to the external resonator, and conversion from the first wavelength to the second wavelength in the process of traveling from the external resonator to the light source unit. And synthesized light. By making it possible to synthesize light with a small number of optical members, a simple and compact configuration can be achieved, and light loss can be reduced. Due to the resonator structure, the second wavelength light can be emitted with high wavelength conversion efficiency. Thereby, a light source device capable of realizing high wavelength conversion efficiency with a simple and small configuration can be obtained.

  Moreover, as a preferable aspect of the present invention, it is desirable that the folded portion has an integral structure. Thereby, a light source device can be simplified and reduced in size.

  Moreover, as a preferable aspect of the present invention, it is desirable that the folded portion includes an optical element that totally reflects light of the second wavelength at the interface. With a simple configuration using a single optical element, the second wavelength light from the wavelength separation unit can be folded back.

  Moreover, as a preferable aspect of the present invention, it is desirable to include a reflection portion that is provided in the optical element and reflects light of the second wavelength. Thereby, the light of the 2nd wavelength from a wavelength separation part can be turned back.

  Moreover, as a preferable aspect of the present invention, the optical element includes a first surface provided with a wavelength separation unit, and a second surface that reflects light having a second wavelength that has passed through the first surface, and the first surface. It is desirable that the second surface is substantially orthogonal. Thereby, it can be set as the structure which returns the light of 2nd wavelength in the direction of an emission destination.

  Moreover, as a preferable aspect of the present invention, the folding unit causes the second wavelength light traveling from the folding unit to the emission destination to travel substantially parallel to the first wavelength light from the light source unit reflected by the wavelength separation unit. It is desirable. Thereby, by setting it as the structure which advances parallel light to an injection | emission destination, the laser beam suitable for illumination use can be supplied.

  Moreover, as a preferable aspect of the present invention, it is desirable that the folded portion emits light from the same surface as the surface on which the light from the wavelength separation portion is incident. Thereby, the space | interval of the light of the 2nd wavelength which permeate | transmitted the external resonator and the light turned up by the folding | turning part can be narrowed, and it can be set as the structure suitable for size reduction further.

  As a preferred embodiment of the present invention, the optical element desirably has a square cross-sectional configuration. An optical element having a square cross-sectional configuration can be easily formed. Thereby, parallel light can be advanced to an emission destination by the structure which can be formed easily.

  As a preferred embodiment of the present invention, it is desirable that the optical element has a cubic shape. Thereby, parallel light can travel to the emission destination, and an optical element can be easily formed.

  Moreover, as a preferable aspect of the present invention, it is desirable that the optical element has a right-angled triangular cross-sectional configuration. An optical element having a right-angled triangular cross-sectional configuration can be easily formed. Moreover, parallel light can be advanced to the emission destination only by total reflection at the interface. Thereby, parallel light can be advanced to an emission destination by the structure which can be formed easily and easily.

  As a preferred aspect of the present invention, the folding unit converges the second wavelength light traveling from the folding unit to the emission destination and the second wavelength light transmitted through the external resonator toward the emission destination. It is desirable. Thereby, the supply object of a laser beam can be reduced in size, and the loss of the laser beam at the emission destination can be reduced.

  As a preferred aspect of the present invention, the folding unit diffuses the second wavelength light traveling from the folding unit to the emission destination and the second wavelength light transmitted through the external resonator toward the emission destination. It is desirable. Thereby, it can be set as the structure which can reduce the energy concentration in a supply target object.

  Moreover, as a preferable aspect of the present invention, the folding unit includes a first mirror that functions as a wavelength separation unit, a second mirror that reflects light of the second wavelength from the first mirror, and a second mirror from the second mirror. It is desirable to have the 3rd mirror which reflects the light of a wavelength. The folding unit including the first mirror, the second mirror, and the third mirror can have a simple configuration and can reduce the manufacturing cost. Accordingly, the second wavelength light can be folded back with an inexpensive and simple configuration.

  Moreover, as a preferable aspect of the present invention, it is desirable to have a fixing portion that fixes the first mirror, the second mirror, and the third mirror. Thereby, a 1st mirror, a 2nd mirror, and a 3rd mirror can be made into an integral structure.

  Moreover, as a preferable aspect of the present invention, it is desirable to have an adhesive layer that adheres at least one of the first mirror, the second mirror, and the third mirror to the fixed portion. Thereby, at least one of the first mirror, the second mirror, and the third mirror can be fixed to the fixing portion.

  Moreover, as a preferable aspect of the present invention, it is desirable to have an elastic structure in which at least one of the first mirror, the second mirror, and the third mirror is brought into contact with the fixed portion. Thereby, at least one of the first mirror, the second mirror, and the third mirror can be fixed to the fixing portion.

  As a preferred aspect of the present invention, the wavelength separation unit reflects a part of the first wavelength light from the external resonator and transmits a part of the first wavelength light and the second wavelength light. It is a 1 wavelength separation part, Comprising: It is desirable for a folding | turning part to have the 2nd wavelength separation part which isolate | separates the light of the 1st wavelength from the wavelength separation part, and the light of the 2nd wavelength. By using the second wavelength separation unit, it is possible to reduce the light of the first wavelength emitted from the light source device when there is light of the first wavelength that passes through the first wavelength separation unit.

  Moreover, as a preferable aspect of the present invention, it is desirable to have a light detection unit that detects light of the first wavelength separated by the second wavelength separation unit. By using the light detection unit, the output of the light source unit can be controlled according to the detection result of the light detection unit. Thereby, the light of the 1st wavelength separated by the 2nd wavelength separation part can be used effectively.

  Moreover, as a preferable aspect of the present invention, it is desirable to have a light absorption part that absorbs light of the first wavelength separated by the second wavelength separation part. Thereby, the emission of light having the first wavelength, which is unnecessary light, can be reduced.

  Furthermore, according to this invention, it can provide the illuminating device which has said light source device and illuminates a to-be-irradiated object using the light from a light source device. By using the above light source device, high wavelength conversion efficiency can be realized with a simple and small configuration. Thereby, the illuminating device which can illuminate with high efficiency by simple and small structure can be obtained.

  Furthermore, according to the present invention, it is possible to provide a monitor device including the above-described illumination device and an imaging unit that captures an image of a subject illuminated by the illumination device. By using the above-described illumination device, illumination with high efficiency is possible with a simple and small configuration. Thereby, a monitor device capable of monitoring a bright image with a simple and small configuration can be obtained.

  Furthermore, according to the present invention, it is possible to provide a projector including the above-described illumination device and a spatial light modulation device that modulates light from the illumination device in accordance with an image signal. By using the above-described illumination device, illumination with high efficiency is possible with a simple and small configuration. Thus, a projector capable of displaying a bright image with a simple and small configuration can be obtained.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a lighting apparatus 10 according to Embodiment 1 of the present invention. The illumination device 10 includes a light source device 11 and a diffusing element 18. The light source device 11 includes a semiconductor element 12, an optical prism 13, an SHG element 16, and an external resonator 17 provided on a substrate 19. The semiconductor element 12 is a light source unit that emits fundamental light having a first wavelength. The first wavelength is, for example, 1064 nm.

  FIG. 2 schematically shows a cross-sectional configuration of the semiconductor element 12. The semiconductor element 12 is a so-called surface-emitting semiconductor element, for example, a substrate 20 made of a semiconductor wafer, a mirror layer 21 formed on the substrate 20 and having a function as a reflection mirror, and laminated on the surface of the mirror layer 21. And a laser medium 22.

  The mirror layer 21 is constituted by a laminate of a high refractive index derivative and a low refractive index derivative formed on the substrate 20 by, for example, CVD (Chemical Vapor Deposition). The thickness of each layer constituting the mirror layer 21, the material of each layer, and the number of layers are optimized with respect to the wavelength (first wavelength) of the fundamental light emitted from the semiconductor element 12, and the reflected light interferes and strengthens each other. The condition is set.

  The laser medium 22 is formed on the surface of the mirror layer 21. The laser medium 22 is connected to a current supply unit (not shown). When a predetermined amount of current is supplied from the current supply unit, the laser medium 22 emits light having a predetermined wavelength. Further, the laser medium 22 amplifies the light of the first wavelength when the light of the first wavelength resonates between the mirror layer 21 and the external resonator 17 shown in FIG. The light reflected by the mirror layer 21 and the external resonator 17 resonates with the light newly emitted by the laser medium 22 and is amplified. The light having the first wavelength is emitted from the emission surface of the laser medium 22 in a direction substantially orthogonal to the mirror layer 21 and the substrate 20.

  Returning to FIG. 1, the SHG element 16 is a wavelength conversion element that converts light having a first wavelength into light having a second wavelength different from the first wavelength. The second wavelength is approximately half the wavelength of the first wavelength, and is, for example, 532 nm.

  FIG. 3 schematically shows a cross-sectional configuration of the SHG element 16. The SHG element 16 has, for example, a quadrangular prism shape. The SHG element 16 includes a wavelength conversion unit 23 and two anti-reflective (AR) films. One AR film 24 is formed on the surface of the wavelength conversion unit 23 on the semiconductor element 12 side. The other AR film 25 is formed on the surface of the wavelength converter 23 on the external resonator 17 side.

  The wavelength conversion unit 23 has a periodic polarization inversion structure, and converts light of the first wavelength into light of the second wavelength by wavelength conversion by quasi phase matching (QPM). However, the wavelength conversion efficiency of the wavelength conversion unit 23 is generally 30 to 40%. That is, not all of the first wavelength light emitted from the semiconductor element 12 is converted to the second wavelength light.

The periodically poled structure is formed inside a crystal substrate of an inorganic nonlinear optical material such as lithium niobate (LiNbO ₃ ; LN) or lithium tantalate (LiTaO ₃ ; LT). Specifically, the periodic domain-inverted structure has two regions 23a in which the polarization directions are reversed in a direction substantially orthogonal to the light emitted from the semiconductor element 12 inside the crystal substrate. A large number of 23b are alternately formed at predetermined intervals. The pitch of these two regions 23a and 23b is appropriately determined in consideration of the wavelength of incident light and the refractive index dispersion of the crystal substrate.

  In general, the light emitted from the semiconductor element 12 oscillates in a plurality of longitudinal modes in the gain band, and their wavelengths change due to the influence of temperature fluctuations or the like. That is, the allowable range of the wavelength of the light converted in the SHG element 16 is about 0.3 nm, and varies about 0.1 nm / ° C. with respect to a change in the use environment temperature.

  The AR films 24 and 25 are dielectric films made of, for example, a single layer or multiple layers, and transmit both the first wavelength light and the second wavelength light with a transmittance of, for example, 98% or more. The AR films 24 and 25 are not essential components for achieving the function of the SHG element 16, and can be omitted. That is, the SHG element 16 may be configured by only the wavelength conversion unit 23.

  Returning to FIG. 1, the external resonator 17 has a function of selectively reflecting light of the first wavelength and transmitting light of wavelengths other than the first wavelength (including the second wavelength). The external resonator 17 transmits light of the second wavelength emitted from the SHG element 16 and travels to the diffusion element 18 that is the emission destination, reflects the light of the first wavelength, and resonates with the semiconductor element 12. Let The external resonator 17 also has a function of narrowing the wavelength of light to be amplified by selectively reflecting light of the first wavelength.

  FIG. 4 schematically shows a cross-sectional configuration of the external resonator 17. The external resonator 17 has a quadrangular prism shape like the SHG element 16. The Bragg grating part 26 is a volume phase grating in which a Bragg grating structure is formed. The AR film 27 is provided on the incident surface of the Bragg grating portion 26.

The Bragg grating portion 26 is composed of a number of layers provided along the optical path. The Bragg grating portion 26 is formed by irradiating a glass layer such as alkali boroaluminosilicate glass mainly composed of SiO ₂ with an ultraviolet ray having a predetermined wavelength to form an interference pattern having a different refractive index in the glass layer. The Bragg grating portion 26 provides the function of the external resonator 17.

  The AR film 27 is a dielectric film composed of a single layer or multiple layers, and transmits both light of the first wavelength and light of the second wavelength with a transmittance of 98% or more, for example. The AR film 27 may be formed not only on the incident surface of the Bragg grating part 26 but also on the exit surface. The AR film 27 is not an essential component for achieving the function of the external resonator 17, and may be omitted. That is, the external resonator 17 may be configured only by the Bragg grating portion 26.

  FIG. 5 shows a perspective configuration of the optical prism 13. The optical prism 13 is an optical element made of a transparent member, for example, optical glass such as BK7. The optical prism 13 has a quadrangular prism shape with a square cross section. As shown in FIG. 1, the optical prism 13 is arranged with the first surface 13 a directed toward the semiconductor element 12 and the SHG element 16. A wavelength separation film 14 is provided on the first surface 13a.

  The second surface 13b is a surface adjacent to the first surface 13a and is orthogonal to the first surface 13a. The optical prism 13 totally reflects the laser light having the second wavelength on the second surface 13b which is an interface. The third surface 13c is a surface parallel to the first surface 13a and faces the first surface 13a. A reflective film 15 is provided on the third surface 13c. The optical prism 13 constitutes a folding portion that folds the laser light of the second wavelength separated by the wavelength separation film 14 in the direction of the diffusing element 18. The folded portion has an integral structure with a single optical prism 13. By using the folded portion having an integral structure, the light source device 11 can be simplified and reduced in size as compared with the case where the folded portion is composed of a plurality of members. Further, it is not necessary to adjust the positions of the elements constituting the folded portion, and positioning of the folded portion and other elements can be facilitated.

  The wavelength separation film 14 is a wavelength separation unit that separates the first wavelength light and the second wavelength light by transmitting the second wavelength light and reflecting the first wavelength light. The wavelength separation film 14 is composed of, for example, a dielectric multilayer film. The dielectric multilayer film can be formed, for example, by CVD, and the thickness of each layer, the material of each layer, and the number of layers constituting the multilayer film are optimized according to required characteristics. The reflective film 15 is a reflective part that reflects the laser light having the second wavelength. The reflective film 15 is configured using a highly reflective member, such as a dielectric multilayer film or a metal film. The light source device 11 may be a semiconductor laser pumped solid state (DPSS) laser, or may be configured to use a solid laser, a liquid laser, a gas laser, or the like.

  The diffusing element 18 shapes and enlarges the illumination area corresponding to the illumination target I, and makes the light amount distribution of the laser light uniform. As the diffusing element 18, for example, a computer generated hologram (CGH) which is a diffractive optical element can be used. The illumination target I is provided at a position where high-order diffracted light from the diffusing element 18, for example, first-order diffracted light and second-order diffracted light is incident, but at a position other than a position where zero-order diffracted light is incident.

  The illumination device 10 employs an off-axis optical system that supplies illumination light to the illumination target I in a direction other than the optical axis direction of the illumination device 10. Thereby, when the light amount of the zero-order diffracted light is larger than that of other diffracted light, only a part on the illumination target I is prevented from being brightened, and illumination light with a good light amount distribution can be obtained. Note that the diffusing element 18 is not limited to the element that diffracts light by transmitting incident light, but may be an element that diffracts light by reflecting incident light. Moreover, if the light quantity distribution of illumination light is favorable in the illumination target I, a configuration in which zero-order diffracted light from the diffusion element 18 is incident on the illumination target I may be used.

  The light having the first wavelength from the semiconductor element 12 is incident on the wavelength separation film 14. The wavelength separation film 14 reflects the light having the first wavelength from the semiconductor element 12 and advances the light toward the SHG element 16. The light transmitted through the SHG element 16 enters the external resonator 17. The light converted from the first wavelength to the second wavelength in the SHG element 16 passes through the external resonator 17 and then enters the diffusion element 18.

  The light having the first wavelength from the SHG element 16 is reflected by the external resonator 17 and then enters the SHG element 16. In the process of traveling from the external resonator 17 to the semiconductor element 12, the light converted from the first wavelength to the second wavelength in the SHG element 16 passes through the wavelength separation film 14. The laser light having the second wavelength transmitted through the wavelength separation film 14 enters the optical prism 13 from the first surface 13a. The optical prism 13 can prevent reflection of laser light having the second wavelength on the first surface 13a by appropriately setting the incident angle of the laser light on the first surface 13a.

  The second wavelength laser light transmitted through the first surface 13a is incident on the second surface 13b. The laser light incident on the second surface 13b is totally reflected by the second surface 13b and then travels in the direction of the third surface 13c. The laser light incident on the third surface 13c is reflected by the reflective film 15, and then travels in the direction of the fourth surface 13d. The laser light incident on the fourth surface 13d is emitted from the optical prism 13 on the fourth surface 13d, and then travels in the direction of the diffusing element 18. The optical prism 13 folds the laser light of the second wavelength separated by the wavelength separation film 14 in the direction of the diffusing element 18. In this manner, the laser light converted from the first wavelength to the second wavelength in the process of traveling from the semiconductor element 12 to the external resonator 17 and the first wavelength in the process of traveling from the external resonator 17 to the semiconductor element 12 are obtained. The laser beam converted to the second wavelength is combined. By making the first surface 13a and the second surface 13b orthogonal to each other, the laser light having the second wavelength can be folded back toward the diffusing element 18.

  The light having the first wavelength incident on the wavelength separation film 14 from the SHG element 16 is reflected by the wavelength separation film 14 and travels toward the semiconductor element 12. The light having the first wavelength incident on the semiconductor element 12 is reflected by the semiconductor element 12. The light having the first wavelength reflected by the semiconductor element 12 travels in the direction of the wavelength separation film 14 together with the light having the first wavelength emitted from the semiconductor element 12. The resonator structure makes it possible to emit laser light of the second wavelength with high wavelength conversion efficiency.

  By reflecting the laser light on the second surface 13 b and the third surface 13 c of the optical prism 13, the second-wavelength laser light traveling from the optical prism 13 to the diffusion element 18 and the semiconductor element 12 reflected on the wavelength separation film 14. The first-wavelength laser light from the light travels substantially in parallel. By using the rectangular prism-shaped optical prism 13, parallel light can be supplied to the diffusing element 18. By making it possible to supply parallel light to the diffusing element 18, it is possible to supply laser light suitable for illumination applications. For example, the light from the diffusing element 18 can be easily collimated by a lens or the like, and the light can be efficiently used using a small optical element or the like.

  By using the wavelength separation film 14 provided on the first surface 13 a, the first wavelength light emitted from the semiconductor element 12 travels in the direction of the SHG element 16 and the first wavelength light from the SHG element 16. And the light of the second wavelength can be separated. Further, since the semiconductor element 12 and the SHG element 16 can be arranged at a narrow interval, it is possible to secure a long space for the SHG element 16. By making it possible to arrange a sufficiently long SHG element 16, high wavelength conversion efficiency by the SHG element 16 can be ensured.

  The light source device 11 can synthesize laser light with a simple and small configuration in which the wavelength separation film 14 and the reflection film 15 are provided on a single optical prism 13. Further, the optical prism 13 can be easily formed by using a quadrangular prism shape. By adopting a configuration using a small number of optical members, it is possible to reduce the loss of laser light via the optical members. Thereby, there exists an effect that high wavelength conversion efficiency is realizable by simple and small composition.

  By disposing the folded portion outside the resonator structure that does not function for the resonance of the first wavelength light, the loss of the first wavelength light due to interface reflection in the resonator structure can be reduced as much as possible. It becomes possible. This enables efficient laser oscillation. Further, when a configuration for turning back the light of the second wavelength is provided in the resonator structure, it is necessary to adjust the configuration in the resonator structure to support both the first wavelength and the second wavelength. On the other hand, by arranging the folded portion outside the resonator structure, it is only necessary to adjust the configuration in the resonator structure to correspond to the first wavelength. For this reason, regarding the configuration in the resonator structure, the number of layers of the dielectric multilayer film can be reduced, the yield can be improved, and the cost can be reduced. As described above, the light source device 11 can achieve efficient laser oscillation, downsizing, and cost reduction.

  A cube-shaped optical prism 29 shown in FIG. 6 may be used as the optical element that is the folded portion. Similar to the optical prism 13 (see FIG. 5), the optical prism 29 can cause the laser light to travel substantially parallel to the emission destination. Similar to the corner cube, the optical prism 29 can be easily configured to emit laser light in substantially the same direction as the laser light incident on the optical prism 29 by providing a relatively high degree of freedom. Moreover, the optical prism 29 can also be easily formed by setting it as a cube shape. The other optical prism may have a shape other than a quadrangular prism shape having a square cross section. For example, a rectangular parallelepiped shape having a rectangular cross section may be used. Further, as described later, other polygonal column shapes other than the quadrangular column shape may be used.

  The light source unit may include a plurality of light emitting units arranged in an array. For example, the semiconductor element 30 illustrated in FIG. 7 includes a plurality of light emitting units 31 arranged in parallel in one row. The semiconductor element 32 shown in FIG. 8 has a plurality of light emitting units 31 arranged in two rows. In addition, the number and row | line | column of the light emission part 31 are not restricted to what is illustrated. When a light source unit having a plurality of light emitting units arrayed in this way is used, the configuration of the optical prism 13, the wavelength separation film 14, the reflection film 15, the SHG element 16, and the external resonator 17 is expanded to correspond to the light source unit. You can do it. Even a configuration including a plurality of light emitting units arranged in an array can be a simple configuration without causing an excessive increase in size of the apparatus. In addition, while maintaining the effect of being able to supply laser light with the same polarization direction with high light utilization efficiency and stable output, it is possible to effectively connect the increase in light quantity due to the array to increase the output from the light source device. Is possible.

As the wavelength conversion element, for example, a third harmonic generation element or the like may be used instead of the SHG element 16. As the nonlinear optical material constituting the wavelength conversion element, in addition to LN and LT, KNbO ₃ , Ba ₂ NaNb ₅ O ₁₅ (BNN), KTiOPO ₄ (KTP), KTiOAsO ₄ (KTA), β-BaB ₂ O ₄ ( Inorganic nonlinear optical materials such as BBO) and LiB ₃ O ₇ (LBO) may be used. Also, low molecular weight compounds such as metanitroaniline, 2-methyl-4-nitroaniline, chalcone, dicyanovinylanisole, 3,5-dimethyl-1- (4-nitrophenyl) pyrazole, N-methoxymethyl-4-nitroaniline An organic material or an organic nonlinear optical material such as a poled polymer may be used. As the external resonator 17, in addition to the volume type phase grating, a crystal type volume hologram, a photopolymer volume hologram, a blazed diffraction grating (diffraction grating whose groove has a sawtooth shape) may be used.

  FIG. 9 shows a schematic configuration of the illumination device 40 according to the first modification of the present embodiment. The light source device 41 of the illumination device 40 includes an optical prism 42 having a pentagonal cross-sectional configuration. As shown in FIG. 10, the optical prism 42 has a pentagonal prism shape. The optical prism 42 includes five surfaces 42a to 42e corresponding to the sides of the pentagonal shape shown in FIG. As shown in FIG. 9, the wavelength separation film 14 is provided on the first surface 42a. The optical prism 42 is an optical element that totally reflects the laser light of the second wavelength on the three surfaces 42b, 42c, and 42d that are interfaces.

  The second-wavelength laser light transmitted through the first surface 42a is totally totally reflected by the second surface 42b, the third surface 42c, and the fourth surface 42d, and then transmits through the fifth surface 42e. By adopting a configuration in which the laser light is folded back by total reflection using the interface, it is possible to reduce the loss of the laser light as compared with the case of using the reflection portion. The second-wavelength laser light traveling from the optical prism 42 to the diffusion element 18 and the second-wavelength laser light transmitted through the external resonator 17 converge toward the diffusion element 18. As shown in FIG. 11, the first surface 42a and the second surface 42b are substantially orthogonal to each other. Regarding the angle α between the second surface 42b and the third surface 42c and the angle β between the third surface 42c and the fourth surface 42d, a relationship of α <β is established.

  With this configuration, the second wavelength laser light from the optical prism 42 and the second wavelength laser light transmitted through the external resonator 17 can be converged. By converging the laser beam toward the diffusing element 18, the diffusing element 18 can be downsized and the loss of the laser beam in the diffusing element 18 can be reduced. In addition to the configuration described in this embodiment, the optical prism may have another polygonal shape including a first surface and a second surface that are substantially orthogonal to each other.

  FIG. 12 shows a schematic configuration of the illumination device 50 according to the second modification of the present embodiment. The light source device 51 of the illumination device 50 includes an optical prism 52 having a hexagonal cross-sectional configuration. The optical prism 52 has a hexagonal prism shape. The optical prism 52 includes six surfaces 52a to 52f corresponding to the hexagonal sides shown in FIG. As shown in FIG. 12, the wavelength separation film 14 is provided on the first surface 52a. The optical prism 52 is supported by placing a bottom surface 52 b adjacent to the first surface 52 a on the substrate 19.

  The second surface 52c adjacent to the bottom surface 52b totally reflects the laser light from the first surface 52a. The optical prism 52 is an optical element that totally reflects the laser light having the second wavelength on the second surface 52c that is an interface. The first surface 52a and the second surface 52c may be substantially orthogonal to each other, or may be configured not to be orthogonal. The second-wavelength laser light transmitted through the first surface 52a is totally reflected by the second surface 52c, and then proceeds in the direction of the third surface 52d adjacent to the second surface 52c. The reflective surface 15 is provided on the third surface 52d. The laser light incident on the third surface 52d is reflected by the reflective film 15 and then travels in the direction of the fourth surface 52f. The fourth surface 52f is a surface that separates one surface 52e from the third surface 52d and is adjacent to the first surface 52a. The laser light traveling in the direction of the fourth surface 52f is emitted to the outside of the optical prism 52 from the fourth surface 52f. The second-wavelength laser light emitted from the optical prism 52 travels in the direction of the diffusing element 18.

  The second wavelength laser light traveling from the optical prism 52 to the diffusion element 18 and the second wavelength laser light transmitted through the external resonator 17 are diffused toward the diffusion element 18. Thereby, it can be set as the structure which can reduce the energy concentration in the diffusion element 18 which is a supply object. Moreover, the optical prism 52 can be easily installed by making it possible to arrange the optical prism 52 using the bottom surface 52b. As described above, the optical prism may have a configuration other than the configuration in which the first surface and the second surface that are substantially orthogonal to each other are adjacent to each other. As the optical prism, for example, an octagonal prism-shaped optical prism 55 having a regular octagonal cross section shown in FIG. 14 may be used. Also in the case of the octagonal prism-shaped optical prism 55, the optical prism 55 can be easily installed with the flat surface as the bottom surface. Furthermore, the optical prism may have a shape other than the shape described in this embodiment.

  FIG. 15 shows a schematic configuration of the light source device 100 used in the illumination device according to the second embodiment of the present invention. The light source device 100 includes an optical prism 101 having a pentagonal cross-sectional configuration. In the cross-sectional configuration of the optical prism 101, the fourth surface 101d and the fifth surface 101e form an obtuse angle. The same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted. In the above embodiment, the semiconductor element 12 is disposed so as to be inclined with respect to the surface of the substrate 19 on which the SHG element 16 is provided and the surface on which the external resonator 17 is provided. The substrate 102 on which the semiconductor element 12 is arranged without being inclined with respect to the surface on which the semiconductor resonator 12 is provided or the surface on which the external resonator 17 is provided is used.

  The optical prism 101, which is an optical element, is obtained by removing the triangular prism shape having the fourth surface 101d and the fifth surface 101e from the quadrangular prism shape having the first surface 101a, the second surface 101b, and the third surface 101c. It has a prismatic shape. A wavelength separation film 14 is provided on the first surface 101a. The second surface 101b is a surface adjacent to the first surface 101a. The optical prism 101 totally reflects the laser light having the second wavelength on the second surface 101b which is an interface. The third surface 101c is a surface adjacent to the second surface 101b and faces the first surface 101a. A reflective film 15 is provided on the third surface 101c. The fourth surface 101d is a surface adjacent to the third surface 101c. The fifth surface 101e is a surface between the fourth surface 101d and the first surface 101a. The optical prism 101 constitutes a folding portion that folds back the laser light having the second wavelength separated by the wavelength separation film 14.

  The light of the first wavelength incident on the wavelength separation film 14 from the semiconductor element 12 and reflected by the wavelength separation film 14 has its optical path bent by about 90 degrees at the wavelength separation film 14 and travels in the direction of the SHG element 16. The light of the first wavelength incident on the wavelength separation film 14 from the SHG element 16 and reflected by the wavelength separation film 14 has its optical path bent by about 90 degrees at the wavelength separation film 14 and travels toward the semiconductor element 12.

  The second-wavelength laser light extracted from the resonator structure by passing through the wavelength separation film 14 enters the optical prism 101 from the first surface 101a. The laser light having the second wavelength is refracted on the first surface 101a. The laser beam having the second wavelength from the first surface 101a is incident on the second surface 101b. The second-wavelength laser light totally reflected by the second surface 101 b is incident on the reflective film 15. The second-wavelength laser light reflected by the reflective film 15 is incident on the fourth surface 101d. The second wavelength laser light is refracted on the fourth surface 101. The second wavelength laser light emitted from the fourth surface 101d from the optical prism 101 travels substantially parallel to the first wavelength light reflected by the wavelength separation film 14.

  The optical prism 101 can be formed relatively easily by cutting out a part of a quadrangular prism-shaped transparent member. In the present embodiment, parallel light can be advanced to the emission destination by a configuration that can be easily formed. By adopting a configuration in which parallel light travels to the emission destination, adjustment of an illumination optical system incorporating the light source device 100 can be facilitated. In addition, the light source device 100 of the present embodiment may advance the convergent light or the diffused light toward the emission destination by appropriately modifying the light source device 100.

  FIG. 16 shows a schematic configuration of the light source device 110 used in the illumination device according to the third embodiment of the present invention. The light source device 110 includes an optical prism 111 having a square cross-sectional configuration. The same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted. A first wavelength separation film 112 that is a first wavelength separation unit is provided on the first surface 111a of the optical prism 111 that is an optical element. The first wavelength separation film 112 is a wavelength separation part that reflects a part of the first wavelength light from the external resonator 17 and transmits a part of the first wavelength light and the second wavelength light.

  The second surface 111b is a surface adjacent to the first surface 111a and is orthogonal to the first surface 111a. The third surface 111c is a surface adjacent to the second surface 111b and is parallel to the first surface 111a. A second wavelength separation film 113 that is a second wavelength separation unit is provided on the third surface 111c. The second wavelength separation film 113 separates the first wavelength light and the second wavelength light from the first wavelength separation film 112 by transmitting the first wavelength light and reflecting the second wavelength light. Let The first fourth surface 111d is a surface between the third surface 111c and the first surface 111a and is parallel to the second surface 111b. The optical prism 111 constitutes a folding portion that folds back the laser light having the second wavelength separated by the first wavelength separation film 112. One side L in the cross-sectional configuration of the optical prism 111 is, for example, 3 mm. The refractive index of the optical prism 111 is, for example, 1.52.

  Light from the semiconductor element 12 is incident on the first surface 111a at an angle of approximately 45 degrees. An angle α formed by the light from the SHG element 16 and the first surface 111a is also approximately 45 degrees. The second-wavelength laser light and the first-wavelength light extracted from the resonator structure by passing through the first wavelength separation film 112 are incident on the optical prism 111 from the first surface 111a. The light incident on the first surface 111a is refracted on the first surface 111a. The light from the first surface 111a is incident on the second surface 111b. The angle β formed between the light incident on the second surface 111b and the second surface 111b is approximately 27.5 degrees. The light totally reflected by the second surface 111 b enters the second wavelength separation film 113.

  The light having the first wavelength incident on the second wavelength separation film 113 is transmitted through the second wavelength separation film 113. The light having the first wavelength transmitted through the second wavelength separation film 113 is incident on the light detection unit 114 after exiting the optical prism 111 from the third surface 111c. The light detection unit 114 detects the light having the first wavelength separated by the second wavelength separation film 113. As the light detection unit 114, for example, a photodiode can be used. The semiconductor element 12 emits light having a controlled intensity based on the detection result by the light detection unit 114. By using the light detection unit 114, feedback control of the output of the semiconductor element 12 is possible.

  The second wavelength laser light reflected by the second wavelength separation film 113 is incident on the first surface 111a. The optical prism 111 that is the folded portion emits light from the first surface 111a that is the same surface as the surface on which the light from the first wavelength separation film 112 is incident. The second-wavelength laser light incident on the first surface 111a is refracted on the first surface 111a. The light exiting the optical prism 111 from the first surface 111 a passes through the first wavelength separation film 112. The laser light having the second wavelength transmitted through the first wavelength separation film 112 travels substantially parallel to the light having the first wavelength reflected by the first wavelength separation film 112.

  The optical prism 111 having a square cross-sectional configuration can be easily formed. By making it possible to easily form the optical prism 111, it is possible to reduce the variation in angle for each light beam and the individual difference in the interval between the light beams. Therefore, the light source device 110 can be easily incorporated in the illumination optical system, and the illumination optical system in which the light source device 110 is incorporated can obtain stable optical performance. Furthermore, the optical prism 111 having a rectangular shape can be easily installed in a vapor deposition apparatus when a wavelength separation film or a reflection film is formed, and a stable film can be formed.

  In this embodiment, by using the optical prism 111 having a small cross-sectional configuration with a side L of about 3 mm, both the incidence of light to the optical prism 111 and the emission of laser light from the optical prism 111 are the first surface. 111a can be used. By enabling the incidence and emission of light using the same first surface 111 a of the optical prism 111, the second wavelength laser light transmitted through the external resonator 17 and the second wavelength emitted from the optical prism 111. The interval with the laser beam can be reduced. By making it possible to emit laser light with a narrow interval, the diffusion element 18 (see FIG. 1) and the elements constituting the optical system can be reduced in size. Thereby, it can be set as the structure suitable for size reduction further.

  By using the second wavelength separation film 113 provided on the optical prism 111 that is the turning portion, the first light emitted from the light source device 110 when light having the first wavelength that passes through the first wavelength separation film 112 exists. Wavelength light can be reduced. Further, the first wavelength light that has been separated by the second wavelength separation film 113 is effectively used by detecting the light having the first wavelength transmitted through the second wavelength separation film 113 by the light detection unit 114. be able to. In the light source device of each of the above embodiments, the second wavelength separation film 113 may be provided in the folded portion. For example, in the case of the light source device 100 shown in FIG. 15, the second wavelength separation film 113 may be provided instead of the reflection film 15. Further, the light source device 110 of the present embodiment may be provided with the reflective film 15 instead of the second wavelength separation film 113.

  FIG. 17 shows a schematic configuration of a light source device 115 according to a modification of the present embodiment. The light source device 115 includes a light absorption unit 116 provided in place of the light detection unit 114 described above. The light absorption unit 116 absorbs light having the first wavelength separated by the second wavelength separation film 113. The light absorption part 116 can be comprised using light absorptive resin, for example. Thereby, the emission of light having the first wavelength, which is unnecessary light, can be reduced. Note that, for example, the lighting device or the housing of the device on which the lighting device is mounted may function as the light absorbing unit.

  FIG. 18 shows a schematic configuration of the light source device 120 used in the illumination device according to the fourth embodiment of the present invention. The light source device 120 includes a dichroic mirror 121 and an optical prism 122. The same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted. The dichroic mirror 121 is provided at a position where light from the semiconductor element 12 and light from the SHG element 16 enter. The dichroic mirror 121 is a wavelength separation unit that reflects light having the first wavelength and transmits light having the second wavelength. The dichroic mirror 121 is configured by applying a dielectric multilayer film to a transparent member formed in a plate shape. The dichroic mirror 121 has a first surface 121a directed to the side on which the SHG element 16 is provided, and a second surface 121b directed to the side on which the optical prism 122 is provided. A dielectric multilayer film (not shown) is formed on the first surface 121a.

  The optical prism 122 that is an optical element is a right-angle prism having a cross-sectional configuration of an isosceles right-angle triangle. The optical prism 122 functions as a folding unit that folds the light from the dichroic mirror 121. The optical prism 122 is arranged with the first surface 122a facing the side on which the dichroic mirror 121 is provided. The second surface 122b of the optical prism 122 is a surface adjacent to the first surface 122a. The third surface 122c of the optical prism 122 is a surface between the first surface 122a and the second surface 122b. The third surface 122c is orthogonal to the second surface 122b.

  Light from the semiconductor element 12 is incident on the first surface 121a of the dichroic mirror 121 at an angle of approximately 45 degrees. The laser light having the second wavelength extracted from the resonator structure by passing through the dichroic mirror 121 is refracted by the first surface 121a and the second surface 121b. The second-wavelength laser light emitted from the dichroic mirror 121 from the second surface 121 b is incident substantially perpendicular to the first surface 122 a of the optical prism 122. The second wavelength laser light incident on the optical prism 122 from the first surface 122a is incident on the second surface 122b at an angle of approximately 45 degrees.

  The second-wavelength laser light incident on the second surface 122b is totally reflected by the second surface 122b, and then enters the third surface 122c at an angle of approximately 45 degrees. The second-wavelength laser light incident on the third surface 122c is totally reflected by the third surface 122c, travels substantially parallel to the incident on the second surface 122b, and is substantially perpendicular to the first surface 122a. Incident. The optical prism 122 emits light from the first surface 122a that is the same surface as the surface on which the light from the dichroic mirror 121 is incident. The second-wavelength laser light transmitted from the first surface 122a through the optical prism 122 travels substantially parallel to the first-wavelength light reflected by the dichroic mirror 121.

  In this embodiment, it is possible to configure the folded portion with a high degree of freedom by providing the wavelength separating portion separately from the folded portion. The optical prism 122 having a right-angled triangular cross-sectional configuration can be easily formed. In addition, by using the optical prism 122 having a small cross-sectional configuration, both the incidence of light to the optical prism 122 and the emission of laser light from the optical prism 122 can be configured to use the first surface 122a. By enabling the incidence and emission of light using the same first surface 122 a of the optical prism 122, the second wavelength laser light transmitted through the external resonator 17 and the second wavelength emitted from the optical prism 111. The interval with the laser beam can be reduced. Thereby, the structure suitable for size reduction is easily realizable using the optical prism 122 of simple shape. In addition, by making it possible to use only total reflection in the optical prism 122, the laser light of the second wavelength can be turned back with a simple configuration that does not require a reflective film.

  FIG. 19 shows a schematic configuration of the light source device 130 used in the illumination device according to the fifth embodiment of the present invention. The light source device 130 according to the present embodiment has a folding part 131 in which three mirrors are combined. The same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 20 shows a perspective configuration of the folded portion 131. The folding unit 131 includes a first mirror 133, a second mirror 134, and a third mirror 135. The first mirror 133 is a dichroic mirror that functions as a wavelength separation unit that reflects light of the first wavelength and transmits light of the second wavelength. The first mirror 133 is configured by applying a dielectric multilayer film to a transparent member formed in a plate shape. The second mirror 134 reflects the light of the second wavelength from the first mirror 133. The third mirror 135 reflects the light of the second wavelength from the second mirror 134. Each of the second mirror 134 and the third mirror 135 is configured by applying a reflective film to a transparent member formed in a plate shape. The first mirror 133, the second mirror 134, and the third mirror 135 all have substantially the same rectangular shape.

  The folding unit 131 has two block structures 132 to which the first mirror 133, the second mirror 134, and the third mirror 135 are fixed. The block structure 132 functions as a fixing unit that fixes the first mirror 133, the second mirror 134, and the third mirror 135. The block structure 132 is provided in accordance with the short sides of the rectangular first mirror 133, the second mirror 134, and the third mirror 135. The block structure 132 has a rectangular parallelepiped shape having a square cross-sectional configuration. The two block structures 132 are arranged so that square-shaped cross sections are substantially parallel. As long as the block structure 132 is strong enough to accurately position the mirrors 133, 134, and 135, any member may be used.

  The first surface 132a and the third surface 132c of the block structure 132 are parallel to each other. The second surface 132b is a surface between the first surface 132a and the third surface 132c. The first mirror 133 is fixed to the first surface 132 a of the block structure 132. The dielectric multilayer film provided on the first mirror 133 is formed on the surface of the first mirror 133 opposite to the surface fixed to the block structure 132. The second mirror 134 is fixed to the second surface 132 b of the block structure 132. The reflective film provided on the second mirror 134 is formed on the surface of the second mirror 134 that is fixed to the block structure 132. The third mirror 135 is provided on the third surface 132 c of the block structure 132. The reflective film provided on the third mirror 135 is formed on the surface of the third mirror 135 that is fixed to the block structure 132.

  The first mirror 133 and the third mirror 135 are positioned by the block structure 132 so as to be parallel to each other. The second mirror 134 is positioned by the block structure 132 so as to be perpendicular to the first mirror 133 and the third mirror 135. The folding part 131 has an integral structure by fixing the first mirror 133, the second mirror 134, and the third mirror 135 to the block structure 132.

  Returning to FIG. 19, the support portion 136 supports the folded portion 131 on the substrate 102. The semiconductor element 12 is incorporated in the support portion 136. The folded portion 131 is disposed using the support portion 136 so that the light from the semiconductor element 12 forms an angle of about 45 degrees with respect to the first surface 132a. An angle θ between the surface of the support 136 that is perpendicular to the substrate 102 and the second mirror 134 is approximately 135 degrees.

  The light of the first wavelength incident on the first mirror 133 from the semiconductor element 12 and reflected by the first mirror 133 has its optical path bent by about 90 degrees by the first mirror 133 and proceeds in the direction of the SHG element 16. The light having the first wavelength incident on the first mirror 133 from the SHG element 16 and reflected by the first mirror 133 has its optical path bent by about 90 degrees by the first mirror 133 and proceeds in the direction of the semiconductor element 12.

  The laser light having the second wavelength extracted from the resonator structure by passing through the first mirror 133 is incident on the second mirror 134. The laser beam having the second wavelength makes an angle of about 45 degrees with respect to the second mirror 134. The second-wavelength laser light whose optical path is bent by approximately 90 degrees by being reflected by the second mirror 134 enters the third mirror 135. An angle of about 45 degrees is formed with respect to the third mirror 135. The second-wavelength laser light whose optical path is bent by approximately 90 degrees by being reflected by the third mirror 135 travels substantially parallel to the first-wavelength light reflected by the first mirror 133.

  FIG. 21 illustrates a procedure for manufacturing the folded portion 131. In step a, the first mirror 133 is fixed to the first surface 132a of the block structure 132. An adhesive member is used to fix the first surface 132a and the first mirror 133. An adhesive layer 137 is formed between the first surface 132a and the first mirror 133. In step b, the second mirror 134 is fixed to the second surface 132b of the block structure 132. An adhesive member is used to fix the second surface 132b and the second mirror 134. An adhesive layer 137 is formed between the second surface 132b and the second mirror 134.

  In step c, the third mirror 135 is fixed to the third surface 132 c of the block structure 132. An adhesive member is used to fix the third surface 132c and the third mirror 135. An adhesive layer 137 is formed between the third surface 132c and the third mirror 135. In this way, the first mirror 133, the second mirror 134, the third mirror 135, and the block structure 132 can be fixed.

  The folding unit 131 including the first mirror 133, the second mirror 134, and the third mirror 135 can have a simple configuration and can reduce the manufacturing cost. Accordingly, the second wavelength laser beam can be folded back with an inexpensive and simple configuration. The block structure 132 is provided at any position between the mirrors 133, 134, and 135 as long as the second wavelength laser light transmitted through the first mirror 133 is incident on the position. Also good.

  FIG. 22 illustrates the configuration of the folding unit 140 according to the first modification of the present embodiment. In the present modification, the mirrors 133, 134, and 135 are fixed to the block structure 132 using three leaf spring portions 142 provided in place of the adhesive layer 137. The leaf spring portion 142 is a plate-shaped elastic structure that causes the first mirror 133, the second mirror 134, and the third mirror 135 to contact the block structure 132. The leaf spring portion 142 is provided on the frame member 141. The frame member 141 has a frame shape in which a portion of the first mirror 133, the second mirror 134, and the third mirror 135 that is in contact with the block structure 132 can be fitted. The frame member 141 and the leaf spring part 142 are configured using, for example, a metal member.

  The leaf spring portion 142 is provided in a portion of the frame member 141 that contacts the first mirror 133, a portion that contacts the second mirror 134, and a portion that contacts the third mirror 135. The leaf spring part 142 is configured to bend toward the outside of the frame member 141, and blocks the first mirror 133, the second mirror 134, and the third mirror 135 using a restoring force directed toward the inside of the frame member 141. Abut against structure 132. Also in this modification, the first mirror 133, the second mirror 134, the third mirror 135, and the block structure 132 can be fixed.

  FIG. 23 illustrates the configuration of the folding unit 150 according to the second modification of the present embodiment. In this modification, the mirrors 133, 134, and 135 are fixed to the block structure 132 using a frame member 151 configured by combining three leaf spring members. The frame member 151 is an elastic structure that causes the first mirror 133, the second mirror 134, and the third mirror 135 to contact the block structure 132. The frame member 151 is configured by combining three leaf spring members and one plate-like member in a frame shape.

  A contact portion 152 having a convex shape toward the inner side of the frame member 151 is formed at the center portion of each leaf spring member. The abutting portion 152 is provided in a portion of the frame member 151 that abuts on the first mirror 133, a portion that abuts on the second mirror 134, and a portion that abuts on the third mirror 135. The frame member 151 is configured to be able to fit a portion of the first mirror 133, the second mirror 134, and the third mirror 135 that is in contact with the block structure 132. The frame member 151 is configured using, for example, a metal member.

  Each leaf spring member is configured to bend toward the outside of the frame member 151 toward the contact portion 152, and the first mirror 133 is configured using a restoring force in a direction to direct the contact portion 152 toward the inside of the frame member 151. The second mirror 134 and the third mirror 135 are brought into contact with the block structure 132. Also in this modification, the first mirror 133, the second mirror 134, the third mirror 135, and the block structure 132 can be fixed.

  Note that the shape of the elastic structure used for the folded portion is not limited to that described in this embodiment, and may be appropriately modified. At least one of the second mirror 134 and the third mirror 135 in the folded portion of the present embodiment may be a dichroic mirror. When the dichroic mirror is used, the light source device 110 according to the third embodiment can be configured to separate the first wavelength light at the folded portion. In addition, the light source device 130 according to the present embodiment may cause the convergent light or diffused light to travel toward the emission destination by appropriately modifying the light source device 130.

  FIG. 24 shows a schematic configuration of a monitor device 60 according to the sixth embodiment of the present invention. The monitor device 60 includes a device main body 62 and an optical transmission unit 63. The apparatus main body 62 includes a light source device 61 having a configuration similar to that of the light source device 11 of the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The light transmission unit 63 includes two light guides 65 and 69. A diffusion lens 67 and an imaging lens 68 are provided at the end of the light transmission unit 63 on the subject (not shown) side. The first light guide 65 transmits the light from the light source device 61 to the subject. The diffusing element 66 and the diffusing lens 67 are provided on the emission side of the first light guide 65. The diffusing element 66 shapes and enlarges the illumination area and makes the light quantity distribution of the laser light uniform. The diffusion lens 67 diffuses the light from the diffusion element 66 on the subject side. Each part in the optical path from the light source device 61 to the diffusing lens 67 constitutes an illumination device that illuminates the subject.

  The second light guide 69 transmits light from the subject to the camera 64. The imaging lens 68 is provided on the incident side of the second light guide 69. The imaging lens 68 condenses light from the subject onto the incident surface of the second light guide 69. Light from the subject enters the second light guide 69 through the imaging lens 68, then propagates through the second light guide 69 and enters the camera 64.

  As the first light guide 65 and the second light guide 69, a bundle of many optical fibers can be used. By using an optical fiber, it is possible to transmit laser light far away. The camera 64 is provided in the apparatus main body 62. The camera 64 is an imaging unit that captures an image of a subject illuminated by each unit in the optical path from the light source device 61 to the diffusion lens 67. By making the light incident from the second light guide 69 enter the camera 64, the camera 64 can image the subject.

  By applying an illumination device including the light source device 61 similar to that of the first embodiment, high wavelength conversion efficiency can be realized with a simple and small configuration. As a result, a bright image can be monitored with a simple and small configuration. The light source device 61 may have the same configuration as any of the light source devices described in the above embodiments.

  FIG. 25 shows a schematic configuration of a projector 70 according to Embodiment 7 of the present invention. The projector 70 is a front projection type projector that observes an image by emitting light to the screen 77 and observing the light reflected by the screen 77. The projector 70 includes a red (R) light illumination device 71R, a green (G) light illumination device 71G, and a blue (B) light illumination device 71B. Each of the color light illumination devices 71R, 71G, 71B has the same configuration as the illumination device 10 of the first embodiment. The projector 70 displays an image using light from each color light illumination device 71R, 71G, 71B.

  The R light illumination device 71R is a light device that supplies R light. The R light spatial light modulator 72R is an irradiation object of the R light illumination device 71R. The R light spatial light modulation device 72R is a spatial light modulation device that modulates the R light from the R light illumination device 71R according to an image signal, and is a transmissive liquid crystal display device. As the transmissive liquid crystal display device, for example, a high temperature polysilicon TFT liquid crystal panel (HTPS) can be used. The R light modulated by the R light spatial light modulator 72R is incident on a cross dichroic prism 73 which is a color synthesis optical system.

  The G light illumination device 71G is a lighting device that supplies G light. The G light spatial light modulation device 72G is a spatial light modulation device that modulates the G light from the G light illumination device 71G according to an image signal, and is a transmissive liquid crystal display device. The G light modulated by the G light spatial light modulator 72G enters the cross dichroic prism 73 from a side different from the R light.

  The illumination device for B light 71B is an illumination device that supplies B light. The B light spatial light modulator 72B is a spatial light modulator that modulates the B light from the B light illumination device 71B in accordance with an image signal, and is a transmissive liquid crystal display device. The B light modulated by the B light spatial light modulator 72B enters the cross dichroic prism 73 from a side different from the R light and G light.

  The cross dichroic prism 73 has two dichroic films 74 and 75 arranged so as to be substantially orthogonal to each other. The first dichroic film 74 reflects R light and transmits G light and B light. The second dichroic film 75 reflects B light and transmits R light and G light. The cross dichroic prism 73 combines the R light, the G light, and the B light incident from different directions and emits them in the direction of the projection lens 76. The projection lens 76 projects the light combined by the cross dichroic prism 73 toward the screen 77.

  By using the same illumination device as that of the first embodiment, it is possible to perform illumination with high efficiency with a simple and small configuration. This produces an effect that a bright image can be displayed with a simple and small configuration. Each of the color light illumination devices 71R, 71G, 71B may have the same configuration as any of the illumination devices described in the above embodiments. The projector 70 is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulation device. As the spatial light modulator, a reflective liquid crystal display (Liquid Crystal On Silicon; LCOS), DMD (Digital Micromirror Device), GLV (Grating Light Valve), or the like may be used. The projector 70 is not limited to a configuration including a spatial light modulator for each color light.

  The projector 70 may be configured to modulate two or three or more color lights with one spatial light modulator. The projector may be a so-called rear projector that supplies light to one surface of the screen and observes an image by observing light emitted from the other surface of the screen. Note that the light source device of the present invention is not limited to the case where the light source device is applied to an illumination device of a projector and a monitor device. For example, it may be used in an exposure apparatus that performs exposure using laser light.

  As described above, the light source device according to the present invention is suitable for application to a lighting device used in a projector or a monitor device.

The figure which shows schematic structure of the illuminating device which concerns on Example 1 of this invention. The figure which represents typically the cross-sectional structure of a semiconductor element. The figure which represents typically the cross-sectional structure of a SHG element. The figure which represents typically the cross-sectional structure of an external resonator. The figure which shows the isometric view structure of an optical prism. The figure explaining the cube-shaped optical prism. The figure which shows the semiconductor element which has several light emission part paralleled in 1 row. The figure which shows the semiconductor element which has several light emission part paralleled in 2 rows. FIG. 6 is a diagram illustrating a schematic configuration of a lighting device according to a first modification of the first embodiment. The figure which shows the isometric view structure of an optical prism. The figure which shows the planar structure of an optical prism. The figure which shows schematic structure of the illuminating device which concerns on the modification 2 of Example 1. FIG. The figure which shows the planar structure of an optical prism. The figure explaining the octagonal prism-shaped optical prism. The figure which shows schematic structure of the light source device which concerns on Example 2 of this invention. The figure which shows schematic structure of the light source device which concerns on Example 3 of this invention. FIG. 10 is a diagram illustrating a schematic configuration of a light source device according to a modification of Example 3; The figure which shows schematic structure of the light source device which concerns on Example 4 of this invention. The figure which shows schematic structure of the light source device which concerns on Example 5 of this invention. The figure which shows the isometric view structure of a folding | returning part. The figure explaining the procedure which manufactures a folding | returning part. FIG. 10 is a diagram illustrating a configuration of a folded portion according to a first modification of the fifth embodiment. FIG. 10 is a diagram illustrating a configuration of a folded portion according to a second modification of the fifth embodiment. The figure which shows schematic structure of the monitor apparatus which concerns on Example 6 of this invention. FIG. 10 is a diagram illustrating a schematic configuration of a projector according to a seventh embodiment of the invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Illuminating device, 11 Light source device, 12 Semiconductor element, 13 Optical prism, 13a 1st surface, 13b 2nd surface, 13c 3rd surface, 13d 4th surface, 14 Wavelength separation film, 15 Reflective film, 16 SHG element, 17 External resonator, 18 diffusion element, 19 substrate, I illumination target, 20 substrate, 21 mirror layer, 22 laser medium, 23 wavelength conversion unit, 23a, 23b region, 24, 25 AR film, 26 Bragg grating unit, 27 AR film , 29 optical prism, 30 semiconductor element, 31 light emitting unit, 32 semiconductor element, 40 illumination device, 41 light source device, 42 optical prism, 42a first surface, 42b second surface, 42c third surface, 42d fourth surface, 42e 5th surface, 50 illumination device, 51 light source device, 52 optical prism, 52a first surface, 52b bottom surface, 52c second surface, 52d first 3 surface, 52e surface, 52f 4th surface, 55 optical prism, 60 monitor device, 61 light source device, 62 device body, 63 light transmission unit, 64 camera, 65 first light guide, 66 diffusing element, 67 diffusing lens, 68 Imaging lens, 69 2nd light guide, 70 projector, 71R R light illumination device, 71G G light illumination device, 71B B light illumination device, 72R R light spatial light modulation device, 72G G light spatial light modulation Device, 72B spatial light modulator for B light, 73 cross dichroic prism, 74 first dichroic film, 75 second dichroic film, 76 projection lens, 77 screen, 100 light source device, 101 optical prism, 101a first surface, 101b first 2 side, 101c 3rd side, 101d 4th side, 101e 5th side, 102 substrate, DESCRIPTION OF SYMBOLS 10 Light source device, 111 Optical prism, 111a 1st surface, 111b 2nd surface, 111c 3rd surface, 111d 4th surface, 112 1st wavelength separation film, 113 2nd wavelength separation film, 114 Light detection part, 115 Light source device , 116 light absorption unit, 120 light source device, 121 dichroic mirror, 121a first surface, 121b second surface, 122 optical prism, 122a first surface, 122b second surface, 122c third surface, 130 light source device, 131 folding unit 132 block structure, 132a first surface, 132b second surface, 132c third surface, 133 first mirror, 134 second mirror, 135 third mirror, 136 support portion, 137 adhesive layer, 140 folded portion, 141 frame member 142 Leaf spring part, 150 Folding part, 151 Frame member, 152 Abutting part

Claims (22)

A light source unit that emits light of a first wavelength;
A wavelength conversion element that converts light of the first wavelength into light of a second wavelength different from the first wavelength;
An external resonator that transmits the light of the second wavelength emitted from the wavelength conversion element and travels to the emission destination, reflects the light of the first wavelength and resonates with the light source unit;
By transmitting light converted from the first wavelength to the second wavelength in the process of traveling from the external resonator to the light source unit, and reflecting the light of the first wavelength, the light of the first wavelength And a wavelength separation part for separating the light of the second wavelength,
A folding portion that folds back the light of the second wavelength separated by the wavelength separation portion in the direction of the emission destination,
The wavelength separation unit reflects the light of the first wavelength from the light source unit and travels in the direction of the wavelength conversion element.   The light source device according to claim 1, wherein the folded portion has an integral structure.   The light source device according to claim 1, wherein the folded portion includes an optical element that totally reflects the light of the second wavelength at an interface.   The light source device according to claim 3, further comprising a reflection unit that is provided in the optical element and reflects the light of the second wavelength. The optical element includes a first surface on which the wavelength separation unit is provided, and a second surface that reflects the light having the second wavelength that has passed through the first surface,
The light source device according to claim 3, wherein the first surface and the second surface are substantially orthogonal to each other.   The folding unit causes the light of the second wavelength that travels from the folding unit to the emission destination to travel substantially parallel to the light of the first wavelength from the light source unit reflected by the wavelength separation unit. The light source device according to any one of claims 1 to 5.   The light source device according to claim 6, wherein the folding unit emits light from the same surface as the surface on which the light from the wavelength separation unit is incident.   The light source device according to claim 6, wherein the optical element has a square cross-sectional configuration.   The light source device according to claim 8, wherein the optical element has a cubic shape.   The light source device according to claim 6, wherein the optical element has a right-angled triangular cross-sectional configuration.   The folding unit converges the light of the second wavelength that travels from the folding unit to the emission destination and the light of the second wavelength that has passed through the external resonator toward the emission destination. The light source device according to any one of claims 1 to 5.   The folding unit diffuses the light of the second wavelength that travels from the folding unit to the emission destination and the light of the second wavelength that has passed through the external resonator toward the emission destination. The light source device according to any one of claims 1 to 5.   The folding unit includes a first mirror that functions as the wavelength separation unit, a second mirror that reflects the second wavelength light from the first mirror, and the second wavelength light from the second mirror. The light source apparatus according to claim 1, further comprising a third mirror that reflects the light source.   The light source device according to claim 13, further comprising a fixing portion that fixes the first mirror, the second mirror, and the third mirror.   The light source device according to claim 14, further comprising an adhesive layer that adheres at least one of the first mirror, the second mirror, and the third mirror to the fixing portion.   The light source device according to claim 14, further comprising an elastic structure in which at least one of the first mirror, the second mirror, and the third mirror is in contact with the fixed portion. The wavelength separation unit is a first wavelength separation unit that reflects a part of the light of the first wavelength from the external resonator and transmits a part of the light of the first wavelength and the light of the second wavelength. There,
The said folding | returning part has a 2nd wavelength separation part which isolate | separates the light of the said 1st wavelength from the said 1st wavelength separation part, and the light of the said 2nd wavelength, The any one of Claims 1-16 characterized by the above-mentioned. The light source device according to one item.   The light source device according to claim 17, further comprising a light detection unit that detects the light having the first wavelength separated by the second wavelength separation unit.   The light source device according to claim 17, further comprising a light absorption unit that absorbs the light having the first wavelength separated by the second wavelength separation unit.   An illumination device comprising the light source device according to any one of claims 1 to 19 and illuminating an object to be irradiated using light from the light source device. The lighting device according to claim 20;
An image pickup unit for picking up an image of a subject illuminated by the illumination device. The lighting device according to claim 20;
And a spatial light modulator that modulates light from the illumination device in accordance with an image signal.

Images