JP2017037948A - Light emitting device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device capable of high heat radiation performance.SOLUTION: A light emitting device includes an active layer, a first cladding layer and a second cladding layer. The second cladding layer has a ridge portion between a first groove portion and a second groove portion provided in the second cladding layer. The active layer constitutes an optical waveguide for guiding light in a region overlapping with the ridge portion when viewed from a lamination direction. The optical waveguide has a first light emitting surface and a second light emitting surface for emitting light. The first groove portion and the second groove portion extend along the optical waveguide when viewed from the lamination direction. The width of the first groove portion and the width of the second groove portion are the widest at the center position where the distances to the first light emitting surface and the second light emitting surface are equal to each other when viewed in the lamination direction, and a heat radiating portion for radiating heat evolved in the optical waveguide is provided in the first groove portion and the second groove portion, and the material of the heat radiating portion is higher in thermal conductivity than the material of the second cladding layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting device and a projector.

  A semiconductor light emitting device such as a semiconductor laser or a super luminescent diode (hereinafter also referred to as “SLD”) is used as a light source of a projector, for example. SLDs are incoherent like ordinary light-emitting diodes, and exhibit a broad spectrum shape, but with an optical output characteristic, it is possible to obtain an output of up to several hundreds mW with a single element like a semiconductor laser. A semiconductor light emitting device.

  For example, in Patent Document 1, a stack of a p-type ridge-like cladding layer and a p-type contact layer is defined between two grooves, and a ridge-like portion composed of the ridge-like cladding layer and the contact layer is defined. An SLD is described that defines a waveguide along multiple quantum well layers.

JP 2002-76432 A

  In the optical waveguide of the SLD as described above, since light is amplified exponentially toward the light exit surface that emits light, a portion where the amount of carriers converted to light is insufficient and not converted to light. The portion where the carrier is excessive is generated. Since the carrier that has not been converted to light changes to heat, the amount of heat generated may increase in a portion where the amount of excess carrier is large. This amount of heat generation becomes a problem particularly when the semiconductor element is mounted on the mounting substrate with the p-type semiconductor layer side facing the mounting substrate (in the case of junction down).

  An object of some aspects of the present invention is to provide a light-emitting device that can have high heat dissipation. Another object of some embodiments of the present invention is to provide a projector including the light-emitting device.

The light emitting device according to the present invention is
An active layer capable of generating light when current is injected;
A first cladding layer and a second cladding layer sandwiching the active layer;
Including
The second cladding layer has a ridge portion between a first groove portion and a second groove portion provided in the second cladding layer,
The active layer constitutes an optical waveguide that guides light in a region overlapping the ridge portion as viewed from the stacking direction of the active layer and the first cladding layer,
The optical waveguide has a first light emitting surface and a second light emitting surface for emitting light,
The first groove portion and the second groove portion extend along the optical waveguide as viewed from the stacking direction,
When viewed from the stacking direction, the width of the first groove and the width of the second groove are widest at the center position where the distances to the first light emitting surface and the second light emitting surface are equal,
The first groove portion and the second groove portion are provided with a heat radiating portion that releases heat generated in the optical waveguide,
The material of the heat radiating part has a higher thermal conductivity than the material of the second cladding layer.

  In such a light emitting device, heat can be released at the center position where the carrier is left, and high heat dissipation can be achieved.

In the light emitting device according to the present invention,
A first electrode and a second electrode for injecting current into the active layer;
A laminate having the first cladding layer, the active layer, and the second cladding layer;
Including
The laminate has a connection region connected to the second electrode,
When viewed from the stacking direction, the width of the connection region may increase from the center position toward the first light exit surface, and may increase from the center position toward the second light exit surface. Good.

  In such a light-emitting device, gain saturation can be reduced and higher output can be achieved.

In the light emitting device according to the present invention,
When viewed from the stacking direction, the width of the ridge portion may increase from the center position toward the first light exit surface, and may increase from the center position toward the second light exit surface. Good.

  In such a light-emitting device, gain saturation can be reduced and higher output can be achieved.

In the light emitting device according to the present invention,
When viewed from the stacking direction, the width of the first groove portion and the width of the second groove portion become narrower from the center position toward the first light emission surface side, and from the center position to the second light emission surface. It may become narrower toward the side.

  In such a light emitting device, the heat dissipation can be gradually changed along the extending direction of the optical waveguide. For example, the heat dissipation can be changed in accordance with the distribution of heat generated in the optical waveguide.

In the light emitting device according to the present invention,
The shape of the first groove portion, the second groove portion, and the optical waveguide may be symmetric with respect to the center position when viewed from the stacking direction.

  In such a light emitting device, the difference between the intensity of the light emitted from the first light emitting surface and the intensity of the light emitted from the second light emitting surface can be reduced.

In the light emitting device according to the present invention,
An antireflection film may be provided on the first light emission surface and the second light emission surface.

  In such a light emitting device, reflection of light on the first light emitting surface and the second light emitting surface can be suppressed, and light can be emitted efficiently from the first light emitting surface and the second light emitting surface. .

In the light emitting device according to the present invention,
The optical waveguide may extend in a direction inclined with respect to a normal line of the first light emission surface and a normal line of the second light emission surface.

  In such a light-emitting device, a direct resonator cannot be configured, so that laser oscillation of light generated in the optical waveguide can be suppressed. As a result, such a light emitting device can reduce speckle noise.

The light emitting device according to the present invention is
An active layer capable of generating light when current is injected;
A first cladding layer and a second cladding layer sandwiching the active layer;
Including
The second cladding layer has a ridge portion between a first groove portion and a second groove portion provided in the second cladding layer,
The active layer constitutes an optical waveguide that guides light in a region overlapping the ridge portion as viewed from the stacking direction of the active layer and the first cladding layer,
The optical waveguide has a light emitting surface for emitting light, and a light reflecting surface for reflecting light,
The first groove portion and the second groove portion extend along the optical waveguide as viewed from the stacking direction,
When viewed from the stacking direction, the width of the first groove and the width of the second groove are widest at the position where the light reflecting surface is provided,
The first groove portion and the second groove portion are provided with a heat radiating portion that releases heat generated in the optical waveguide,
The material of the heat radiating part has a higher thermal conductivity than the material of the second cladding layer.

  In such a light emitting device, heat can be released at a position where the light reflecting surface where the carrier is left is provided, and high heat dissipation can be achieved.

In the light emitting device according to the present invention,
A first electrode and a second electrode for injecting current into the active layer;
A laminate having the first cladding layer, the active layer, and the second cladding layer;
Including
The laminate has a connection region connected to the second electrode,
When viewed from the stacking direction, the width of the connection region may increase from the light reflecting surface side toward the light emitting surface side.

  In such a light-emitting device, gain saturation can be reduced and higher output can be achieved.

In the light emitting device according to the present invention,
As viewed from the stacking direction, the width of the ridge portion may increase from the light reflecting surface side toward the light emitting surface side.

  In such a light-emitting device, gain saturation can be reduced and higher output can be achieved.

In the light emitting device according to the present invention,
When viewed from the stacking direction, the width of the first groove portion and the width of the second groove portion may become narrower from the light reflecting surface side toward the light emitting surface side.

  In such a light emitting device, the heat dissipation can be gradually changed along the extending direction of the optical waveguide. For example, the heat dissipation can be changed in accordance with the distribution of heat generated in the optical waveguide.

In the light emitting device according to the present invention,
The light exit surface is provided with an antireflection film,
A reflective film may be provided on the light reflecting surface.

  In such a light emitting device, reflection of light on the light exit surface can be suppressed, and light can be efficiently emitted from the light exit surface. Further, in such a light emitting device, it is possible to suppress the transmission of light on the light reflecting surface, and to efficiently reflect light on the light reflecting surface.

In the light emitting device according to the present invention,
A plurality of the optical waveguides may be arranged.

  In such a light emitting device, high output can be achieved.

In the light emitting device according to the present invention,
A light emitting device comprising: the active layer; the first cladding layer; the second cladding layer; and a first electrode and a second electrode for injecting current into the active layer;
A mounting substrate on which the light emitting element is mounted;
Including
The light emitting element may be connected to the mounting substrate by the heat radiating portion.

  In such a light emitting device, the heat radiating portion can be used as a bonding member when the light emitting element is mounted.

The projector according to the present invention is
A light emitting device according to the present invention;
A light modulation device that modulates light emitted from the light emitting device according to image information;
A projection device for projecting an image formed by the light modulation device;
including.

  Such a projector can include a light-emitting device with high heat dissipation.

The figure which shows typically the light-emitting device which concerns on 1st Embodiment. Sectional drawing which shows typically the light-emitting device which concerns on 1st Embodiment. Sectional drawing which shows typically the light-emitting device which concerns on 1st Embodiment. The figure for demonstrating the relationship between the position of the extension direction of an optical waveguide, and light intensity. The figure for demonstrating the relationship between the position of the extension direction of an optical waveguide, and the amount of carriers. Sectional drawing which shows typically the manufacturing process of the light-emitting device which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the light-emitting device which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the light-emitting device which concerns on 1st Embodiment. The figure which shows typically the light-emitting device which concerns on the 1st modification of 1st Embodiment. Sectional drawing which shows typically the light-emitting device which concerns on the 1st modification of 1st Embodiment. The figure which shows typically the light-emitting device which concerns on the 1st modification of 1st Embodiment. The figure which shows typically the light-emitting device which concerns on the 1st modification of 1st Embodiment. The figure for demonstrating the relationship between the position of the extension direction of an optical waveguide, and light intensity. The figure which shows typically the light-emitting device which concerns on the 2nd modification of 1st Embodiment. The figure which shows typically the light-emitting device which concerns on 2nd Embodiment. The figure which shows typically the light-emitting device which concerns on the modification of 2nd Embodiment. The figure which shows typically the projector which concerns on 3rd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. 1. First embodiment 1.1. First, the light emitting device according to the first embodiment will be described with reference to the drawings. FIG. 1 is a diagram schematically showing a light emitting device 100 according to the first embodiment. 2 is a cross-sectional view taken along the line II-II in FIG. 1 schematically showing the light emitting device 100 according to the first embodiment. 3 is a cross-sectional view taken along the line III-III of FIG. 1 schematically showing the light emitting device 100 according to the first embodiment.

  As illustrated in FIGS. 1 to 3, the light emitting device 100 includes a light emitting element 2, a mounting substrate 4, and a heat radiating unit 6. The light emitting element 2 includes a stacked body 101, an insulating layer 112, a first electrode 120, a second electrode 122, and an antireflection film 140. The stacked body 101 includes a substrate 102, a first cladding layer 104, an active layer 106, a second cladding layer 108, and a contact layer 110. 1 is a view of the light emitting element 2 of the light emitting device 100 as viewed from the second electrode 122 side, and is a view in which the second electrode 122 is omitted.

  The substrate 102 is, for example, a first conductivity type (for example, n-type) GaAs substrate.

  The first cladding layer 104 is provided under the substrate 102. The first cladding layer 104 is, for example, an n-type InGaAlP layer. Although not shown, a buffer layer may be formed between the substrate 102 and the first cladding layer 104. The buffer layer is, for example, an n-type GaAs layer, an AlGaAs layer, an InGaP layer, or the like. The buffer layer can improve the crystal quality of the layer formed therebelow.

  The active layer 106 is provided on the first cladding layer 104. The active layer 106 has, for example, a multiple quantum well (MQW) structure in which three quantum well structures each composed of an InGaP well layer and an InGaAlP barrier layer are stacked.

  As shown in FIG. 1, the active layer 106 includes a first side surface 106a, a second side surface 106b, a third side surface 106c, and a fourth side surface 106d. The side surfaces 106a and 106b are surfaces (parallel surfaces in the illustrated example) that face in opposite directions. The side surfaces 106c and 106d are surfaces facing in opposite directions (parallel surfaces in the illustrated example) and are surfaces connected to the side surfaces 106a and 106b. The side surfaces 106a, 106b, 106c, and 106d are surfaces that are not in contact with the cladding layers 104 and 108 in a planar shape. The side surfaces 106a and 106b may be cleaved surfaces formed by cleavage.

  The active layer 106 is a layer that can generate light by being injected with current. The active layer 106 constitutes an optical waveguide 160 that guides light. Light guided through the optical waveguide 160 can receive a gain in the optical waveguide 160.

  The optical waveguide 160 has a band shape when viewed from the stacking direction of the active layer 106 and the first cladding layer 104 (also referred to as “in plan view”), and extends from the first side surface 106a to the second side surface 106b. Yes. In the illustrated example, the size of the optical waveguide 160 in the direction parallel to the first side surface 106a is constant from the first side surface 106a to the second side surface 106b in plan view. The planar shape (shape in plan view) of the optical waveguide 160 is, for example, a parallelogram.

  The optical waveguide 160 has a first light emission surface 170 and a second light emission surface 172 that emit light. The first light exit surface 170 is a connection portion with the first side surface 106 a of the optical waveguide 160. The second light emission surface 172 is a connection portion with the second side surface 106 b of the optical waveguide 160. The optical waveguide 160 extends in a direction inclined with respect to the normal line P1 of the first light output surface 170 and the normal line P2 of the second light output surface 172. In the illustrated example, the center line α of the optical waveguide 160 extends in a direction inclined with respect to the normal lines P1 and P2. The center line α is an imaginary straight line that passes through the center of the first light exit surface 170 and the center of the second light exit surface 172.

  The optical waveguide 160 has a center position C where the distances to the first light exit surface 170 and the second light exit surface 172 are equal. In the example shown in FIG. 1, the center position C is a point on the center line α that has the same distance to the light emitting surfaces 170 and 172.

  The second cladding layer 108 is provided under the active layer 106. The second cladding layer 108 is, for example, a second conductivity type (for example, p-type) InGaAlP layer. The cladding layers 104 and 108 are layers having a larger band gap and a lower refractive index than the active layer 106. The clad layers 104 and 108 have a function of suppressing leakage of injected carriers (electrons and holes) and light with the active layer 106 interposed therebetween.

  In the light emitting device 100, the p-type second cladding layer 108, the active layer 106 not doped with impurities, and the n-type first cladding layer 104 constitute a pin diode. In the light emitting device 100, when a forward bias voltage of a pin diode is applied between the electrodes 120 and 122 (current is injected), recombination of electrons and holes occurs in the optical waveguide 160. This recombination causes light emission. With this generated light as a starting point, stimulated emission occurs in a chain, and the intensity of the light is amplified in the optical waveguide 160. The optical waveguide 160 includes an active layer 106 that guides light and clad layers 104 and 108 that suppress light leakage.

  The second cladding layer 108 is provided with a first groove 150 and a second groove 152. The second cladding layer 108 includes a fifth side surface 108 a that is continuous with the first side surface 106 a of the active layer 106, and a sixth side surface 108 b that is continuous with the second side surface 106 b of the active layer 106. The groove portions 150 and 152 extend from the fifth side surface 108a to the sixth side surface 108b.

  The first groove 150 and the second groove 152 extend along the optical waveguide 160 in plan view. Specifically, an imaginary straight line (not shown) passing through the center between the center of the connection portion of the first groove portion 150 with the fifth side surface 108a and the center of the connection portion of the first groove portion 150 with the sixth side surface 108b is , Parallel to the center line α. Similarly, an imaginary straight line (not shown) passing through the center between the center of the connection portion with the fifth side surface 108a of the second groove portion 152 and the center of the connection portion with the sixth side surface 108b of the second groove portion 152 is It is parallel to the center line α. In the illustrated example, the first groove 150 is provided on the third side face 106c side, and the second groove 152 is provided on the fourth side face 106d side. In a plan view, the combined shape of the first groove 150, the second groove 152, and the optical waveguide 160 is symmetric (point symmetric) with respect to the center position C, for example.

  The width W1 of the first groove 150 and the width W2 of the second groove 152 are widest at the center position C in plan view. Specifically, the widths W1 and W2 of the groove portions 150 and 152 are the widest in the virtual straight line β passing through the center position C and orthogonal to the center line α in plan view. Here, the widths W1 and W2 of the grooves 150 and 152 (widths at a position in the extending direction of the optical waveguide 160) W1 and W2 are sizes in a direction orthogonal to the center line α of the grooves 150 and 152 in plan view.

The first groove portion 150 includes, for example, a first portion 150a located at the center position C and a first portion 15.
It has the 2nd part 150b located in the 5th side 108a side rather than 0a, and the 3rd part 150c located in the 6th side 108b side rather than the 1st part 150a. The second groove 152 includes, for example, a fourth portion 152a positioned at the center position C, a fifth portion 152b positioned closer to the fifth side surface 108a than the fourth portion 152a, and a sixth side surface 108b relative to the fourth portion 152a. And a sixth portion 152c located on the side. The width W1 is constant in the portions 150a, 150b, and 150c, and the width W2 is constant in the portions 152a, 152b, and 152c. The width W1 of the first portion 150a and the width W2 of the fourth portion 152a are the same size. The width W1 of the portions 150b and 150c and the width W2 of the portions 152b and 152c are the same size. The widths W1, W2 of the portions 150a, 152a are wider than the widths W1, W2 of the portions 150b, 150c, 152b, 152c.

  The second cladding layer 108 has a ridge portion 128 between the first groove portion 150 and the second groove portion 152. The ridge portion 128 extends from the fifth side surface 108a to the sixth side surface 108b. The planar shape of the ridge portion 128 is the same as the planar shape of the optical waveguide 160, for example. The active layer 106 constitutes the optical waveguide 160 in a region overlapping the ridge portion 128 in plan view.

  As shown in FIGS. 2 and 3, the contact layer 110 is provided under the second cladding layer 108. The contact layer 110 is provided between the ridge portion 128 and the second electrode 122. The contact layer 110 is, for example, a p-type GaAs layer. The contact layer 110 is connected to the second electrode 122 (specifically, ohmic contact). The contact layer 110 is a layer having higher conductivity than the cladding layers 104 and 108.

  The contact layer 110 and the ridge portion 128 constitute a columnar portion 111. The light emitting device 100 is a refractive index guided SLD. In plan view, the planar shape of the optical waveguide 160 is the same as the planar shape of the columnar section 111, for example.

  The stacked body 101 constituted by the contact layer 110, the second cladding layer 108, the active layer 106, the first cladding layer 104, and the substrate 102 has a connection region 130 connected to the second electrode 122. . In the illustrated example, the contact layer 110 is connected to the second electrode 122 in the connection region 130. The connection region 130 is a contact surface between the contact layer 110 and the second electrode 122, and the contact layer 110 has the connection region 130.

The insulating layer 112 is provided below the second cladding layer 108, on the side of the columnar part 111 (around the columnar part 111 in plan view) and on a part below the columnar part 111. For example, the planar shape of the connection region 130 is determined by the planar shape of the opening of the insulating layer 112 provided on the columnar part 111. In the illustrated example, the insulating layer 112 is also provided in the groove portions 150 and 152. The insulating layer 112 is, for example, a SiN layer, a SiO ₂ layer, a SiON layer, an Al ₂ O ₃ layer, or a polyimide layer. When the above material is used for the insulating layer 112, the current between the electrodes 120 and 122 flows through the columnar portion 111 sandwiched between the insulating layers 112, avoiding the insulating layer 112. The insulating layer 112 has a refractive index smaller than that of the second cladding layer 108, for example.

  The first electrode 120 is provided on the substrate 102. The first electrode 120 is provided on the upper surface of a layer (the substrate 102 in the illustrated example) that is in ohmic contact with the first electrode 120. The first electrode 120 is one electrode for driving the light emitting device 100 (injecting current into the active layer 106). As the first electrode 120, for example, a layer in which a Cr layer, an AuGe layer, a Ni layer, and an Au layer are stacked in this order from the first cladding layer 104 side is used.

The second electrode 122 is provided below the ridge portion 128. Specifically, the second electrode 1
22 is provided under the contact layer 110 and under the insulating layer 112. In the illustrated example, the second electrode 122 is also provided in the groove portions 150 and 152. The second electrode 122 is the other electrode for driving the light emitting device 100 (injecting current into the active layer 106). As the second electrode 122, for example, an electrode in which a Cr layer, an AuZn layer, and an Au layer are stacked in this order from the contact layer 110 side is used.

An anti-reflection (AR) film 140 is provided on the light exit surfaces 170 and 172. In the illustrated example, the antireflection film 140 is provided on the side surfaces 106a and 106b. The antireflection film 140 is, for example, a SiO ₂ layer, a Ta ₂ O ₅ layer, an Al ₂ O ₃ layer, a TiN layer, a TiO ₂ layer, a SiON layer, a SiN layer, or a multilayer film thereof.

  The mounting substrate 4 is a substrate on which the light emitting element 2 including the stacked body 101, the insulating layer 112, the first electrode 120, the second electrode 122, and the antireflection film 140 is mounted. The material of the mounting substrate 4 is, for example, ceramics or metal, and is not particularly limited as long as the light emitting element 2 can be mounted. The light emitting element 2 is mounted on the mounting substrate 4 with the second electrode 122 side facing the mounting substrate 4 (junction down). The light emitting element 2 is connected to the mounting substrate 4 by, for example, a heat radiating unit 6.

  The heat dissipating unit 6 is provided under the second electrode 122. The heat radiation part 6 is provided in the groove parts 150 and 152. The heat radiation part 6 is provided so as to fill the groove parts 150 and 152, for example. The material of the heat radiating part 6 has higher thermal conductivity than the material of the second cladding layer 108. The heat radiation part 6 may be a silver paste, or may be a laminate of a gold layer formed by plating and a silver paste provided under the gold layer. The heat radiating unit 6 can release the heat generated in the optical waveguide 160.

  Although the AlGaInP-based light emitting device 100 has been described above, any material system capable of forming the light emitting device and the optical waveguide according to the present invention can be used. As the semiconductor material, for example, semiconductor materials such as AlGaN, GaN, InGaN, GaAs, AlGaAs, InGaAs, InGaAsP, InP, GaP, AlGaP, and ZnCdSe can be used.

  The light emitting device 100 can be applied to a light source such as a projector, a display, a lighting device, and a measuring device.

  For example, the light emitting device 100 has the following characteristics.

  In the light emitting device 100, in plan view, the width W1 of the first groove 150 and the width W2 of the second groove 152 are the widest at the center position C, and heat generated in the optical waveguide 160 is released to the grooves 150 and 152. A heat dissipating part 6 is provided. Therefore, in the light emitting device 100, heat can be released at the center position C where the carrier is left, and high heat dissipation can be achieved. As a result, the light emitting device 100 can have high reliability, for example.

Here, FIG. 4 is a diagram for explaining the relationship between the position in the extending direction of the optical waveguide and the light intensity. FIG. 5 is a diagram for explaining the relationship between the position in the extending direction of the optical waveguide and the amount of carriers. 4 and 5, the position in the extending direction of the optical waveguide on the horizontal axis is between the first light exit surface (one end of the optical waveguide) and the second light exit surface (the other end of the optical waveguide). The position in the extending direction of the optical waveguide is shown. In Figure 4, the intensity I ₁ of the light traveling from the first light exit surface to the second light emitting surface, and the intensity I ₂ of the light from the second light exit surface toward the first light exit surface, the intensity I ₁ and the intensity I ₂ and the total intensity I _TOTAL . The light intensity on the vertical axis in FIG. 4 is the number of photons passing through a cross section perpendicular to the extending direction of the optical waveguide per unit time at a position in the extending direction of the optical waveguide. .

In general, in SLD, light is amplified exponentially toward a light exit surface (side with a low reflectance). Therefore, as shown in FIG. 4, the light intensity has a non-uniform distribution in the extending direction of the optical waveguide. The distribution of the intensity I _TOTAL is substantially the same as the distribution of the consumed carrier amount at the position in the extending direction of the optical waveguide. As a result, as shown in FIG. 5, when the amount of current per unit length is constant in the extending direction of the optical waveguide, the carrier consumption is large in the vicinity of the light exit surface, and the light is consumed (with respect to photons). ) The carrier is relatively short. That is, when light is about to be amplified, there are not enough carriers to be converted to light (excess or deficiency of carriers occurs). As a result, gain saturation occurs on the light exit surface side where the light intensity is high, and the light output is reduced accordingly. For convenience, FIG. 4 does not show a decrease in optical output due to gain saturation. Further, the amount of current per unit length is the amount of current that flows in the stacking direction (for example, the stacking direction of the active layer 106 and the first cladding layer 104) at a position in the extending direction of the optical waveguide. is there.

  On the other hand, at the center position C of the optical waveguide, there are more carriers than in the vicinity of the light exit surface, the carriers are not sufficiently converted to light, and there are surplus carriers (excess carriers are generated). Therefore, at the center position C, heat generated by the surplus carrier is increased.

  In the light emitting device 100, as described above, the widths W1 and W2 of the groove portions 150 and 152 are the widest at the center position C, and the heat dissipation portion 6 is provided in the groove portions 150 and 152. Heat from the surplus carrier can be released by the heat radiating unit 6. Therefore, the light emitting device 100 can have high heat dissipation. 2 and 3 indicate the flow of heat generated in the optical waveguide 160.

  Furthermore, in the light emitting device 100, the widths W1 and W2 of the groove portions 150 and 152 are narrow in the vicinity of the light emitting surfaces 170 and 172 with few surplus carriers. Therefore, in the light emitting device 100, compared with the case where the widths W1 and W2 of the grooves 150 and 152 in the positions near the light emitting surfaces 170 and 172 are the same as the widths W1 and W2 at the center position C, the stress at the time of mounting is the columnar portion 111. It can suppress that reliability falls by concentrating on.

  In the light emitting device 100, the shape of the first groove 150, the second groove 152, and the optical waveguide 160 is symmetrical with respect to the center position C in plan view. Therefore, in the light emitting device 100, the portion of the optical waveguide 160 closer to the first light exit surface 170 than the center position C (more than the virtual straight line β), and the portion closer to the second light exit surface 172 than the center position C. The difference in heat dissipation can be reduced. Therefore, in the light emitting device 100, the difference between the intensity of the light emitted from the first light emitting surface 170 and the intensity of the light emitted from the second light emitting surface 172 can be reduced.

  In the light emitting device 100, an antireflection film 140 is provided on the light emitting surfaces 170 and 172. Therefore, in the light emitting device 100, reflection of light on the light emitting surfaces 170 and 172 can be suppressed, and light can be efficiently emitted from the light emitting surfaces 170 and 172.

  In the light emitting device 100, the optical waveguide 160 extends in a direction inclined with respect to the normal line P1 of the first light output surface 170 and the normal line P2 of the second light output surface 172. Therefore, in the light emitting device 100, it is possible to suppress the multiple reflection of the light generated in the optical waveguide 160 directly between the light emitting surfaces 170 and 172. Thereby, in the light-emitting device 100, since a direct resonator cannot be comprised, the laser oscillation of the light which generate | occur | produces in the optical waveguide 160 can be suppressed. As a result, the light emitting device 100 can reduce speckle noise. The light emitting device 100 is an SLD.

  In the light emitting device 100, the light emitting element 2 is connected to the mounting substrate 4 by the heat radiating unit 6. Therefore, in the light emitting device 100, the heat radiating part 6 can be used as a joining member when the light emitting element 2 is mounted.

1.2. Method for Manufacturing Light-Emitting Device Next, a method for manufacturing the light-emitting device 100 according to the first embodiment will be described with reference to the drawings. 6-8 is sectional drawing which shows typically the manufacturing process of the light-emitting device 100 which concerns on 1st Embodiment.

  As shown in FIG. 6, the first cladding layer 104, the active layer 106, the second cladding layer 108, and the contact layer 110 are epitaxially grown in this order on the substrate 102. Thereby, the laminated body 101 can be formed. Examples of the epitaxial growth method include a MOCVD (Metal Organic Chemical Deposition) method and an MBE (Molecular Beam Epitaxy) method.

  As shown in FIG. 7, the contact layer 110 and the second cladding layer 108 are patterned to form the columnar portion 111. The patterning is performed by, for example, photolithography and etching. Note that the etching of the contact layer 110 and the second cladding layer 108 may be performed simultaneously or separately. By this step, the groove portions 150 and 152 and the ridge portion 128 can be formed.

  As shown in FIG. 8, an insulating layer 112 is formed on the second cladding layer 108 and the contact layer 110 so as to cover the side surface of the columnar portion 111. Specifically, the insulating layer 112 is formed by forming an insulating member (not shown) by a CVD (Chemical Vapor Deposition) method (more specifically, a plasma CVD method) or a coating method, and patterning the insulating member. It is formed by. The patterning is performed by, for example, photolithography and etching.

  Next, the second electrode 122 is formed on the contact layer 110. Next, the first electrode 120 is formed under the substrate 102. The electrodes 120 and 122 are formed by, for example, a vacuum deposition method or a sputtering method. Note that the order of forming the electrodes 120 and 122 is not particularly limited.

  As shown in FIG. 1, an antireflection film 140 is formed on the light emitting surfaces 170 and 172. The antireflection film 140 is formed by, for example, a CVD method or a sputtering method. The antireflection film 140 may be formed before the electrodes 120 and 122 are formed.

  Through the above steps, the light-emitting element 2 can be formed.

  As shown in FIG. 2, the light emitting element 2 is mounted on the mounting substrate 4 with the second electrode 122 side facing the mounting substrate 4. The light emitting element 2 is connected to the mounting substrate 4 by the heat radiating portion 6.

  Through the above steps, the light emitting device 100 can be manufactured.

1.3. Modified example of light emitting device 1.3.1. First Modification Next, a light-emitting device according to a first modification of the first embodiment will be described with reference to the drawings. FIG. 9 is a diagram schematically showing a light emitting device 200 according to a first modification of the first embodiment. 10 schematically shows a light emitting device 200 according to a second modification of the first embodiment, taken along line XX in FIG.
It is line sectional drawing. 10 is a view of the light emitting element 2 of the light emitting device 200 as viewed from the second electrode 122 side, and is a view in which the second electrode 122 is omitted.

  Hereinafter, in the light emitting device 200 according to the first modification of the first embodiment, members having the same functions as those of the constituent members of the light emitting device 100 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is given. Is omitted. The same applies to the light emitting device according to the second modification of the first embodiment described below.

  In the light emitting device 200, as shown in FIG. 9, the shape of the ridge 128 and the shape of the connection region 130 are different from those of the light emitting device 100 shown in FIG.

  In the light emitting device 200, the ridge portion 128 includes the boundary line 28a on the third side surface 106c side (for example, the boundary line between the ridge portion 128 and the insulating layer 112) and the boundary line 28b on the fourth side surface 106d side (for example, with the ridge portion 128). A boundary line with the insulating layer 112).

  Here, FIG. 11 is an enlarged view of FIG. 1 schematically showing the vicinity of the first light exit surface 170. FIG. 12 is an enlarged view of FIG. 1 schematically showing the vicinity of the second light emission surface 172. For convenience, the antireflection film 140 and the grooves 150 and 152 are omitted in FIGS. 11 and 12.

  As shown in FIGS. 11 and 12, the intersections of the boundary line 28a and the side surfaces 106a and 106b are defined as Q1 and R1, respectively. Intersections between the boundary line 28b and the side surfaces 106a and 106b are denoted by S1 and T1, respectively. Let U1 be the intersection of the virtual straight line L1 passing through the intersection Q1 and orthogonal to the center line α and the boundary line 28b. Let V1 be the intersection of a virtual straight line L2 passing through the intersection T1 and orthogonal to the center line α and the boundary line 28a.

  The ridge portion 128 has a first region 128a, a second region 128b, and a third region 128c in plan view. The first region 128a is a region surrounded by a portion from the intersection point Q1 to the intersection point V1 of the boundary line 28a, a portion from the intersection point U1 to the intersection point T1 of the boundary line 28b, a line segment Q1U1, and a line segment T1V1. It is. The second region 128b is a region surrounded by the line segment Q1U1, the line segment S1U1, and the line segment Q1S1. The third region 128c is a region surrounded by the line segment T1V1, the line segment R1V1, and the line segment R1T1. The planar shape of the first region 128a is, for example, a shape in which the upper sides of two trapezoids are connected to each other. The planar shape of the second region 128b and the third region 128c is, for example, a triangle.

  The width W3 of the ridge portion 128 increases in the plan view from the center position C toward the first light exit surface 170 side and increases from the center position C toward the second light exit surface 172 side.

  Here, the width (width at a position in the extending direction of the optical waveguide 160) W3 of the ridge portion 128 passes through the boundary lines 28a and 28b and is orthogonal to the center line α as in the first region 128a, for example. When a straight line (orthogonal straight line) is drawn, it is the length between the boundary lines 28a and 28b of the orthogonal straight line. On the other hand, when an orthogonal straight line passing through the boundary lines 28a and 28b and orthogonal to the center line α cannot be drawn as in the second region 128b and the third region 128c, the width W3 is the intersection point in the second region 128b. The length of the straight line (line segment) drawn from Q1 to the boundary line 28b is the length of the straight line (line segment) drawn from the intersection T1 to the boundary line 28a in the third region 128c.

The width W3 of the ridge portion 128 is the narrowest at the center position C. For example, the width W3 becomes the widest at the positions of the light emitting surfaces 170 and 172. The ridge portion 128 has a tapered portion that becomes wider from the center position C toward the first light emitting surface 170 side, and a second portion from the center position C.
And a tapered portion that becomes wider toward the light exit surface 172 side.

  The connection region 130 includes a boundary line 30a on the third side surface 106c side (for example, a boundary line between the contact layer 110 and the insulating layer 112) and a boundary line 30b on the fourth side surface 106d side (for example, the contact layer 110 and the insulating layer 112). Boundary line). As shown in FIGS. 11 and 12, the intersection of the boundary line 30a and the first side surface 106a is defined as Q2. The intersection of the boundary line 30b and the second side surface 106b is T2.

  In plan view, the connection region 130 has a width W4 that increases from the center position C toward the first light exit surface 170 and increases from the center position C toward the second light exit surface 172.

  Here, the width W4 of the connection region 130 (the width at a position in the extending direction of the optical waveguide 160) W4 passes through the boundary lines 30a and 30b and the center line α, similarly to the width of the ridge portion 128 described above. When an orthogonal straight line (orthogonal straight line) can be drawn, it is the length between the boundary lines 30a and 30b of the orthogonal straight line. On the other hand, when an orthogonal straight line passing through the boundary lines 30a and 30b and orthogonal to the center line α cannot be drawn, the width W4 is the length of a straight line (line segment) drawn from the intersection point Q2 to the boundary line 30b, or This is the length of a straight line (line segment) drawn from the intersection T2 to the boundary line 30a.

  The width W4 of the connection region 130 is the narrowest at the center position C. For example, the width W4 is widest at the positions of the light exit surfaces 170 and 172. The connection region 130 has a tapered portion that becomes wider from the center position C toward the first light emitting surface 170 side, and a tapered portion that becomes wider from the center position C toward the second light emitting surface 172 side. .

  The width W1 of the first groove 150 and the width W2 of the second groove 150 are narrower toward the first light exit surface 170 side (to the first side surface 106a) from the center position C in the plan view, and the center position. It narrows from C toward the second light exit surface 172 side (to the second side surface 106b side).

  The light emitting device 200 can have a high heat dissipation property, similar to the light emitting device 100.

  Further, in the light emitting device 200, in the plan view, the width W4 of the connection region 130 becomes wider from the center position C toward the first light emission surface 170 side, and from the center position C to the second light emission surface 172 side. It gets wider as you go. Therefore, in the light emitting device 200, gain saturation can be reduced and higher output can be achieved. The reason will be described below.

  FIG. 13 is a diagram for explaining the relationship between the position in the extending direction of the optical waveguide and the light intensity. The horizontal axis of FIG. 13 indicates the position in the extending direction of the optical waveguide between the position of the line segment Q1U1 and the position of the line segment T1V1.

  As described above, in the vicinity of the light exit surface where the light intensity is large (line segment Q1U1 side, line segment T1V1 side), there are not enough carriers to be converted into light, so that saturation of gain occurs, and the light output is correspondingly increased. Decrease (see broken line in FIG. 13). On the other hand, the portion where the light intensity is low (for example, the center position C) is in a state where there are more carriers than on the light exit surface side, and the carriers are not sufficiently converted to light, and the carriers remain. Therefore, high power and high efficiency driving can be performed by injecting a current for generating such surplus carriers to the light emitting surface side where the carriers are insufficient. That is, by changing the amount of current per unit length, gain saturation can be reduced and the final light output can be increased while keeping the injected current amount of the entire optical waveguide constant.

  In the light emitting device 200, as described above, the width W4 of the connection region 130 becomes wider from the center position C toward the first light exit surface 170, and from the center position C toward the second light exit surface 172. As it gets wider. Therefore, in a plan view, in the extending direction of the optical waveguide 160 between the position of the line segment Q1U1 and the position of the line segment T1V1, the amount of current per unit length of the optical waveguide 160 is changed from the center position C to the light emitting surface. It can be increased toward the 170, 172 side. Therefore, in the light emitting device 200, it is possible to suppress a decrease in optical output due to gain saturation without increasing the amount of current injected into the entire optical waveguide 160. That is, in the light emitting device 200, gain saturation can be reduced and higher output can be achieved.

  In the light emitting device 200, in plan view, the width W3 of the ridge portion 128 increases from the center position C toward the first light exit surface 170 side, and from the center position C toward the second light exit surface 172 side. Become wider. Therefore, in the light emitting device 200, for example, the planar shape of the ridge portion 128 and the planar shape of the connection region 130 are made closer to each other than when the width W3 of the ridge portion 128 is constant from the line segment Q1U1 to the line segment T1V1 in plan view. Can do. Therefore, in the light emitting device 200, the injection current can be efficiently converted into light, and the gain saturation can be reduced more effectively and the output can be increased.

  In the light emitting device 200, the widths W1 and W2 of the grooves 150 and 152 in the plan view become narrower from the center position C toward the first light exit surface 170, and from the center position C to the second light exit surface 172 side. It becomes narrower as it goes to. Therefore, in the light emitting device 200, the heat dissipation can be gradually changed along the extending direction of the optical waveguide 160. For example, the heat dissipation can be changed in accordance with the distribution of heat generated in the optical waveguide 160. .

  Although not shown, in the light emitting device 100 described above, the widths W1 and W2 of the groove portions 150 and 152 in the plan view become narrower from the center position C toward the first light emitting surface 170 side and the center position. It may be narrower from C toward the second light exit surface 172 side.

1.3.2. Second Modified Example Next, a light emitting device according to a second modified example of the first embodiment will be described with reference to the drawings. FIG. 14 is a diagram schematically showing a light emitting device 300 according to a second modification of the first embodiment. 14 is a view of the light emitting element 2 of the light emitting device 300 as viewed from the second electrode 122 side, and is a view in which the second electrode 122 is omitted.

  The light emitting device 100 described above has one optical waveguide 160 as shown in FIG. On the other hand, the light-emitting device 300 has a plurality of optical waveguides 160 as shown in FIG. In the illustrated example, the light emitting device 200 includes three optical waveguides 160. The plurality of optical waveguides 160 are arranged along the direction from the third side surface 106c of the active layer 106 toward the fourth side surface 106d in plan view.

  The light emitting device 300 can have a high heat dissipation property, similar to the light emitting device 100. Furthermore, in the light emitting device 300, since a plurality of the optical waveguides 160 are arranged, higher output can be achieved. Although not shown, a plurality of the optical waveguides 160 of the light emitting device 200 may be arranged like the light emitting device 300.

2. Second Embodiment 2.1. Next, a light emitting device according to a second embodiment will be described with reference to the drawings. FIG. 15 is a diagram schematically illustrating a light emitting device 400 according to the second embodiment. FIG. 15 is a view of the light emitting element 2 of the light emitting device 300 as viewed from the second electrode 122 side, and is a view in which the second electrode 122 is omitted.

  Hereinafter, in the light emitting device 400 according to the second embodiment, members having the same functions as the constituent members of the light emitting device 100 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the light emitting device 100, as shown in FIG. 1, the first light emitting surface 170 is provided on the first side surface 106a of the active layer 106, and the second light emitting surface 172 is provided on the first side surface 106b.

On the other hand, in the light emitting device 400, the light emitting surface 170 that emits light is provided on the first side surface 106a, and the light reflecting surface 174 that reflects light is provided on the second side surface 106b. The optical waveguide 160 has a light emitting surface 170 and a light reflecting surface 174. An antireflection film 140 is provided on the light emitting surface 170. The light reflection surface 174 is provided with a reflection film (high-reflection film) 142. In the illustrated example, the reflective film 142 is provided on the second side surface 106b. The reflective film 142 is, for example, a SiO ₂ layer, a Ta ₂ O ₅ layer, an Al ₂ O ₃ layer, a TiN layer, a TiO ₂ layer, a SiON layer, a SiN layer, or a multilayer film thereof.

  In the illustrated example, the optical waveguide 160 extends in the direction of the normal line P1 of the light emitting surface 170 and the normal line P3 of the light reflecting surface. That is, the center line α of the optical waveguide 160 is parallel to the normal lines P1 and P3. The planar shape of the optical waveguide 160 is, for example, a rectangle. In plan view, the width W3 of the ridge 128 and the width W4 of the connection region 130 are constant from the light emitting surface 170 to the light reflecting surface 174. Although not shown, the optical waveguide 160 may extend in a direction inclined with respect to the normal line P1 of the light emitting surface 170 and the normal line P3 of the light reflecting surface.

  The width W1 of the first groove 150 and the width W2 of the second groove 152 are the widest at the position where the light reflecting surface 174 is provided (in the second side surface 106b). In the illustrated example, the first groove portion 150 includes a seventh portion 150d located on the second side surface 106b side and an eighth portion 150e located on the first side surface 106a side. The second groove portion 152 includes a ninth portion 152d located on the second side surface 106b side and a tenth portion 152e located on the first side surface 106a side. The width W1 is constant in the portions 150d and 150e, and the width W2 is constant in the portions 152d and 152e. The width W1 of the seventh portion 150d and the width W2 of the ninth portion 152d are the same size. The width W1 of the eighth portion 150e and the width W2 of the tenth portion 152e are the same size. The widths W1 and W2 of the portions 150d and 152d are wider than the widths W1 and W2 of the portions 150e and 152e.

  In the light emitting device 400, the optical waveguide 160 has a light emitting surface 170 and a light reflecting surface 174, and carriers are not sufficiently converted to light on the light reflecting surface 174, and there are many surplus carriers. For this reason, heat generation by surplus carriers is increased on the light reflecting surface 174.

  In the light emitting device 400, the widths W1 and W2 of the groove portions 150 and 152 are the widest at the position where the light reflecting surface 174 is provided, and the heat radiating portion 6 is provided in the groove portions 150 and 152. Heat from the excessive carrier at the position can be released by the heat dissipating unit 6. Therefore, the light emitting device 400 can have a high heat dissipation property, similar to the light emitting device 100.

In the light emitting device 400, the light emission surface 170 is provided with the antireflection film 140, and the light reflection surface 174 is provided with the reflection film 142. Therefore, in the light emitting device 400, reflection of light on the light emitting surface 170 can be suppressed, and light can be emitted from the light emitting surface 170 efficiently. Furthermore, in the light emitting device 400, light transmission through the light reflecting surface 174 can be suppressed, and light can be efficiently reflected at the light reflecting surface 174.

2.2. Method for Manufacturing Light Emitting Device Next, a method for manufacturing the light emitting device 400 according to the second embodiment will be described. The manufacturing method of the light emitting device 400 according to the second embodiment is basically the same as the manufacturing method of the light emitting device 100 according to the first embodiment. Therefore, the detailed description is abbreviate | omitted.

2.3. Next, a light emitting device according to a modified example of the second embodiment will be described with reference to the drawings. FIG. 16 is a diagram schematically illustrating a light emitting device 500 according to a modification of the second embodiment. FIG. 16 is a view of the light emitting element 2 of the light emitting device 500 as viewed from the second electrode 122 side, and is a view in which the second electrode 122 is omitted.

  Hereinafter, in the light emitting device 500 according to the modified example of the second embodiment, members having the same functions as those of the light emitting device 100 according to the first embodiment and the components of the light emitting device 400 according to the second embodiment are denoted by the same reference numerals. And detailed description thereof is omitted.

  In the light emitting device 400 described above, as shown in FIG. 15, the width W3 of the ridge portion 128 and the width W4 of the connection region 130 are constant from the light emitting surface 170 to the light reflecting surface 174 in plan view.

  On the other hand, in the light emitting device 500, as shown in FIG. 16, in plan view, the width W3 of the ridge 128 and the width W4 of the connection region 130 increase from the light reflecting surface 174 side toward the light emitting surface 170 side. Become. In plan view, the width W1 of the first groove 150 and the width W2 of the second groove 152 become narrower from the light reflecting surface 174 side toward the light emitting surface 170 side.

  The light-emitting device 500 can have high heat dissipation properties, similar to the light-emitting device 400.

  Further, in the light emitting device 500, the width W4 of the connection region 130 becomes wider from the light reflecting surface 174 side toward the light emitting surface 170 side. Therefore, in the light emitting device 500, similarly to the light emitting device 200, gain saturation can be reduced and higher output can be achieved.

  In the light emitting device 500, the width W4 of the connection region 130 increases from the light reflecting surface 174 side toward the light emitting surface 170 side. Therefore, in the light emitting device 500, gain saturation can be reduced and higher output can be achieved.

  In the light emitting device 500, the width W1 of the first groove 150 and the width W2 of the second groove 152 become narrower from the light reflecting surface 174 side toward the light emitting surface 170 side. Therefore, in the light emitting device 500, the heat dissipation can be gradually changed along the extending direction of the optical waveguide 160, similarly to the light emitting device 200. For example, the heat dissipation is performed in accordance with the distribution of heat generated in the optical waveguide 160. Sex can be changed.

  Although not shown, a plurality of the optical waveguides 160 of the light emitting device 500 may be arranged like the light emitting device 300.

3. Third Embodiment Next, a projector according to a third embodiment will be described with reference to the drawings. FIG. 17 is a diagram schematically illustrating a projector 900 according to the third embodiment.

As shown in FIG. 17, the projector 900 includes a red light source 300R that emits red light, green light, and blue light, a green light source 300G, and a blue light source 300B. The red light source 300R, the green light source 300G, and the blue light source 300B are light emitting devices according to the present invention. Hereinafter, an example in which the light emitting device 300 is used as the light emitting device according to the present invention will be described. For the sake of convenience, in FIG. 170, the casing that constitutes the projector 900 is omitted, and the light sources 300R, 300G, and 300B are simplified.

  The projector 900 further includes lens arrays 902R, 902G, and 902B, transmissive liquid crystal light valves (light modulation devices) 904R, 904G, and 904B, and a projection lens (projection device) 908.

  Light emitted from the light sources 300R, 300G, and 300B is incident on the lens arrays 902R, 902G, and 902B. The lens arrays 902R, 902G, and 902B have incident surfaces 901 on which light emitted from the first light emitting surface 170 is incident on the light sources 300R, 300G, and 300B side. The incident surface 901 is, for example, a flat surface. A plurality of incident surfaces 901 are provided corresponding to the plurality of first light emitting surfaces 170 and are arranged at equal intervals. A normal line (not shown) of the incident surface 901 is inclined with respect to the first side surface 106a. By the incident surface 901, the optical axis of the light emitted from the first light emitting surface 170 can be orthogonal to the irradiation surface 905 of the liquid crystal light valves 904R, 904G, and 904B.

  The lens arrays 902R, 902G, and 902B have an emission surface 903 on the liquid crystal light valves 904R, 904G, and 904B side. The emission surface 903 is, for example, a convex surface. A plurality of exit surfaces 903 are provided corresponding to the plurality of entrance surfaces 901 and are arranged at equal intervals. The light whose optical axis is converted on the incident surface 901 can be superposed (partially superposed) by being condensed by the exit surface 903 or by reducing the diffusion angle. Thereby, the liquid crystal light valves 904R, 904G, and 904B can be irradiated with good uniformity.

  As described above, the lens arrays 902R, 902G, and 902B can condense the light by controlling the optical axis of the light emitted from the first light emitting surface 170.

  The light condensed by the lens arrays 902R, 902G, and 902B is incident on the liquid crystal light valves 904R, 904G, and 904B. Each of the liquid crystal light valves 904R, 904G, and 904B modulates incident light according to image information. The projection lens 908 enlarges and projects an image (image) formed by the liquid crystal light valves 904R, 904G, and 904B onto a screen (display surface) 910.

  In addition, the projector 900 can include a cross dichroic prism (color light combining unit) 906 that combines light emitted from the liquid crystal light valves 904R, 904G, and 904B and guides the light to the projection lens 908.

  The three color lights modulated by the liquid crystal light valves 904R, 904G, and 904B are incident on the cross dichroic prism 906. This prism is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged in a cross shape on the inner surface thereof. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 910 by the projection lens 908 which is a projection optical system, and an enlarged image is displayed.

In the example shown in FIG. 17, the light emitted from the second light emission surface 172 provided on the second side surface 106b is not shown, but the light is incident on the reflection unit and the lens array (not shown). Then, the light may enter the liquid crystal light valves 904R, 904G, and 904B.

  The projector 900 can include the light emitting device 300 having high heat dissipation.

  The projector 900 is a method (backlight method) in which the light emitting device 200 is disposed immediately below the liquid crystal light valves 904R, 904G, and 904B, and condensing and uniform illumination are performed simultaneously using the 902R, 902G, and 902B. Therefore, the projector 900 can reduce the loss of the optical system and the number of parts.

  In the above example, a transmissive liquid crystal light valve is used as the light modulation device. However, a light valve other than liquid crystal may be used, or a reflective light valve may be used. Examples of such a light valve include a reflection type liquid crystal light valve and a digital micromirror device (Digital Micromirror Device). Further, the configuration of the projection optical system is appropriately changed depending on the type of light valve used.

  Further, the light sources 300R, 300G, and 300B have scanning means that is an image forming apparatus that displays an image of a desired size on the display surface by causing the light from the light sources 300R, 300G, and 300B to scan on the screen. The present invention can also be applied to a light source device of a simple scanning image display device (projector).

  In the present invention, a part of the configuration may be omitted within a range having the characteristics and effects described in the present application, or each embodiment or modification may be combined.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 2 ... Light emitting element, 4 ... Mounting board, 6 ... Radiation part, 28a, 28b, 30a, 30b ... Borderline, 100 ... Light-emitting device, 101 ... Laminated body, 102 ... Substrate, 104 ... First clad layer, 106 ... Active Layer, 106a ... first side, 106b ... second side, 106c ... third side, 106d ... fourth side, 108 ... second cladding layer, 108a ... fifth side, 108b ... sixth side, 110 ... contact layer, 111 ... Columnar part, 112 ... Insulating layer, 120 ... First electrode, 122 ... Second electrode, 128 ... Ridge part, 128a ... First region, 128b ... Second region, 128c ... Third region, 130 ... Connection region, 140: antireflection film, 142: reflection film, 150: first groove, 150a: first part, 150b: second part, 150c ... third part, 150d ... seventh part, 150e ... eighth part, 152 ... first 2 grooves , 152a ... fourth part, 152b ... fifth part, 152c ... sixth part, 152d ... nine part, 152e ... tenth part, 160 ... optical waveguide, 170 ... first light exit surface, 172 ... second light exit Surface, 174 ... Light reflecting surface, 200, 300, 400, 500 ... Light emitting device, 900 ... Projector, 901 ... Incident surface, 902R, 902G, 902B ... Lens array, 904R, 904G, 904B ... Liquid crystal light valve, 905 ... Irradiation Surface, 906 ... Cross dichroic prism, 908 ... Projection lens, 910 ... Screen

Claims (15)

An active layer capable of generating light when current is injected;
A first cladding layer and a second cladding layer sandwiching the active layer;
Including
The second cladding layer has a ridge portion between a first groove portion and a second groove portion provided in the second cladding layer,
The active layer constitutes an optical waveguide that guides light in a region overlapping the ridge portion as viewed from the stacking direction of the active layer and the first cladding layer,
The optical waveguide has a first light emitting surface and a second light emitting surface for emitting light,
The first groove portion and the second groove portion extend along the optical waveguide as viewed from the stacking direction,
When viewed from the stacking direction, the width of the first groove and the width of the second groove are widest at the center position where the distances to the first light emitting surface and the second light emitting surface are equal,
The first groove portion and the second groove portion are provided with a heat radiating portion that releases heat generated in the optical waveguide,
The light emitting device according to claim 1, wherein a material of the heat radiating portion is higher in thermal conductivity than a material of the second cladding layer. A first electrode and a second electrode for injecting current into the active layer;
A laminate having the first cladding layer, the active layer, and the second cladding layer;
Including
The laminate has a connection region connected to the second electrode,
When viewed from the stacking direction, the width of the connection region increases from the center position toward the first light exit surface, and increases from the center position toward the second light exit surface. The light-emitting device according to claim 1.   When viewed from the stacking direction, the width of the ridge portion increases from the center position toward the first light exit surface, and increases from the center position toward the second light exit surface. The light-emitting device according to claim 2.   When viewed from the stacking direction, the width of the first groove portion and the width of the second groove portion become narrower from the center position toward the first light emission surface side, and from the center position to the second light emission surface. The light-emitting device according to claim 1, wherein the light-emitting device becomes narrower toward the side.   5. The shape according to claim 1, wherein a shape of the first groove portion, the second groove portion, and the optical waveguide is symmetrical with respect to the center position when viewed from the stacking direction. The light-emitting device of description.   The light emitting device according to claim 1, wherein an antireflection film is provided on the first light emitting surface and the second light emitting surface.   7. The optical waveguide according to claim 1, wherein the optical waveguide extends in a direction inclined with respect to a normal line of the first light emission surface and a normal line of the second light emission surface. 2. The light emitting device according to item 1. An active layer capable of generating light when current is injected;
A first cladding layer and a second cladding layer sandwiching the active layer;
Including
The second cladding layer has a ridge portion between a first groove portion and a second groove portion provided in the second cladding layer,
The active layer constitutes an optical waveguide that guides light in a region overlapping the ridge portion as viewed from the stacking direction of the active layer and the first cladding layer,
The optical waveguide has a light emitting surface for emitting light, and a light reflecting surface for reflecting light,
The first groove portion and the second groove portion extend along the optical waveguide as viewed from the stacking direction,
When viewed from the stacking direction, the width of the first groove and the width of the second groove are widest at the position where the light reflecting surface is provided,
The first groove portion and the second groove portion are provided with a heat radiating portion that releases heat generated in the optical waveguide,
The light emitting device according to claim 1, wherein a material of the heat radiating portion is higher in thermal conductivity than a material of the second cladding layer. A first electrode and a second electrode for injecting current into the active layer;
A laminate having the first cladding layer, the active layer, and the second cladding layer;
Including
The laminate has a connection region connected to the second electrode,
The light emitting device according to claim 8, wherein the width of the connection region increases from the light reflecting surface side toward the light emitting surface side when viewed from the stacking direction.   10. The light emitting device according to claim 9, wherein the width of the ridge portion increases from the light reflecting surface side toward the light emitting surface side when viewed from the stacking direction.   The width of the first groove part and the width of the second groove part as viewed from the stacking direction become narrower from the light reflecting surface side toward the light emitting surface side. The light emitting device according to claim 1. The light exit surface is provided with an antireflection film,
The light-emitting device according to claim 8, wherein a reflection film is provided on the light reflection surface.   The light emitting device according to claim 1, wherein a plurality of the optical waveguides are arranged. A light emitting device comprising: the active layer; the first cladding layer; the second cladding layer; and a first electrode and a second electrode for injecting current into the active layer;
A mounting substrate on which the light emitting element is mounted;
Including
The light emitting device according to claim 1, wherein the light emitting element is connected to the mounting substrate by the heat radiating portion. The light emitting device according to any one of claims 1 to 14,
A light modulation device that modulates light emitted from the light emitting device according to image information;
A projection device for projecting an image formed by the light modulation device;
Including a projector.