JP2015087661A - Optical waveguide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical waveguide device in which an optical fiber or the like can be easily connected to an output end of an optical waveguide.SOLUTION: An optical waveguide device includes: a substrate; an optical waveguide formed on the substrate; and prevention means that prevents, among light inputted to an input surface where an input side end of the optical waveguide is provided, non-input light that is not inputted to the optical waveguide from reaching an output surface where an output side end of the optical waveguide is provided.

Description

  The present invention relates to an optical waveguide device.

  An optical modulator in which an optical waveguide is formed on a substrate has been proposed (for example, Patent Document 1).

JP 2006-53189 A

  Light emitted from an optical fiber or the like is input to the optical waveguide of the optical modulator as described above, but part of the light emitted from the optical fiber or the like becomes non-input light that is not input to the optical waveguide. There is a case. The non-input light then passes through various paths, and a part thereof is emitted from the surface (output surface) of the substrate where the output end of the optical waveguide is located. In this case, since both the light output from the optical waveguide and the non-input light exist on the output surface, the light output from the optical waveguide when the optical fiber is connected to the output end of the optical waveguide. And non-input light cannot be distinguished from each other, making it difficult to connect an optical fiber or the like to the output end of the optical waveguide.

  One aspect of the present invention has been made in view of the above problems, and an object of the present invention is to provide an optical waveguide device in which an optical fiber or the like can be easily connected to the output end of the optical waveguide. To do.

  One aspect of the optical waveguide device according to the present invention includes: a substrate; an optical waveguide formed on the substrate; and the light input to an input surface provided with an input side end of the optical waveguide. Suppression means for suppressing non-input light that is not input to the waveguide from reaching the output surface provided with the output side end of the optical waveguide.

  An output side member having one side surface included in the output surface may be provided on the optical waveguide, and the suppression unit may be provided in the output side member.

  The suppression unit may be a reflective element that reflects at least a part of the non-input light.

  The suppression unit may be a light scattering element that scatters at least a part of the non-input light.

  The suppression unit may be an absorption element that absorbs at least part of the non-input light.

  The suppression unit may be an optical element having a slope inclined with respect to the optical path direction of the non-input light.

  An input side member having one side surface included in the input surface may be provided on the optical waveguide, and the suppression unit may be provided in the input side member.

  According to one aspect of the present invention, an optical waveguide device in which an optical fiber or the like can be easily connected to the output end of the optical waveguide is provided.

It is a perspective view which shows the optical waveguide device of 1st Embodiment. It is a sectional side view which shows the optical waveguide device of 1st Embodiment. It is a front view which shows the optical waveguide device of 1st Embodiment. It is the elements on larger scale which show the optical waveguide device of 1st Embodiment. It is a sectional side view of the optical waveguide device in which the reflecting film is not provided. It is a rear view of the optical waveguide device in which the reflecting film is not provided. It is a sectional side view which shows the optical waveguide device of 2nd Embodiment. It is a sectional side view which shows the optical waveguide device of 3rd Embodiment. It is a perspective view which shows the optical waveguide device of 4th Embodiment. It is a top view which shows the optical waveguide device of 4th Embodiment.

Hereinafter, an optical waveguide device according to an embodiment of the present invention will be described with reference to the drawings.
The scope of the present invention is not limited to the following embodiment, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, the actual structure may be different from the scale, number, or the like in each structure.

(First embodiment)
1 to 3 are diagrams showing an optical waveguide device 10 of the present embodiment. FIG. 1 is a perspective view. FIG. 2 is a sectional side view. FIG. 3 is a front view. In FIG. 3, the optical fiber 30 is indicated by a two-dot chain line.

  In the following description, an XYZ coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ coordinate system. At this time, the thickness direction of the substrate 11 (see FIG. 1) is the Z-axis direction, the longitudinal direction of the substrate 11 is the X-axis direction, and the width direction of the substrate 11 is the Y-axis direction.

  As shown in FIGS. 1 and 2, the optical waveguide device 10 of the present embodiment includes a substrate 11, a cladding layer 12, an optical waveguide 13, an input-side member 20, an output-side member 21, and a reflective film 22. , A reflection film 23, an optical fiber (light emitting means) 30, and an optical fiber 31.

The substrate 11 is a rectangular parallelepiped member, such as a silicon substrate, a glass substrate, a ceramic substrate, or a lithium niobate (LiNbO ₃ : LN) substrate. The thickness (Z-axis direction length) of the substrate 11 is, for example, about 0.5 mm. The length of the substrate 11 is, for example, about 5 mm or more and 30 mm or less. On the substrate 11, a clad layer 12 having an optical waveguide 13 provided therein is formed.

  In the present embodiment, the optical waveguide 13 is linearly formed from the input side (−X side) end to the output side (+ X side) end inside the cladding layer 12. That is, the optical waveguide 13 is a so-called straight type optical waveguide. An input side end 13 a of the optical waveguide 13 is provided on the input surface 14 of the optical waveguide device 10. The output side end 13 b of the optical waveguide 13 is provided on the output surface 15 of the optical waveguide device 10. The optical waveguide 13 is optically connected to the optical fiber 30 and the optical fiber 31.

  As shown in FIG. 3, the cross-sectional shape of the optical waveguide 13 is approximately the same or smaller than the input light emitted from the core 32 of the optical fiber 30. The short-axis direction length (Z-axis direction length) in the cross section of the optical waveguide 13 is, for example, 2 μm or more and 10 μm or less. The long-axis direction length (Y-axis direction length) in the cross section of the optical waveguide 13 is, for example, 2 μm or more and 10 μm or less.

The optical waveguide 13 is composed of at least two kinds of polymers such as organic polymer, inorganic polymer, or organic-inorganic composite material.
These polymers can be used as long as they have high transmittance with respect to light propagating through the optical waveguide 13. Examples of these polymers include acrylic resins such as polymethyl methacrylate, epoxy resins, polyimide resins, silicone resins, polystyrene resins, polyamide resins, polyester resins, phenol resins, polyquinoline resins, poly resins. Examples thereof include quinoxaline resins, polybenzoxazole resins, polybenzothiazole resins, polybenzimidazole resins, and the like.

  Moreover, it is possible to adjust the characteristics of the optical waveguide 13 or to provide functionality by adding other components such as organic pigments and inorganic fine particles to the polymer as necessary. Any of these components can be used without particular limitation as long as it has a high transmittance for light propagating through the optical waveguide 13 as in the case of the polymer.

  The clad layer 12 is an organic polymer layer formed on the upper surface (+ Z side surface) of the substrate 11. An optical waveguide 13 is provided inside the cladding layer 12. The clad layer 12 is made of, for example, an organic polymer similar to the organic polymer used for the optical waveguide 13. The thickness (length in the Z-axis direction) of the cladding layer 12 is, for example, 2 μm or more and 20 μm or less.

  The input surface 14 is a side surface to which the optical fiber 30 in the optical waveguide device 10 is connected. In this embodiment, the input surface 14 includes an input side surface (one side surface) 20 a of the input side member 20, an input side surface 11 a of the substrate 11, and a side surface on the input side (−X side) of the cladding layer 12. It is a surface.

  The output surface 15 is a side surface to which the optical fiber 31 in the optical waveguide device 10 is connected. In this embodiment, the output surface 15 includes an output side surface (one side surface) 21a of the output side member 21, an output side surface 11b of the substrate 11, and a side surface on the output side (+ X side) of the cladding layer 12. Surface.

  The input side member 20 is provided at the input side (−X side) end on the cladding layer 12. In the present embodiment, the input side member 20 has a rectangular parallelepiped shape. The input side surface 20 a of the input side member 20 is included in the input surface 14. That is, the input side member 20 is provided such that the input side surface 20 a is flush with the input side surface 11 a of the substrate 11. “Same surface” is a state in which a flat surface is formed in which the surfaces are continuous without a step. A reflection film (reflection element, suppression means) 22 is formed on the output side surface 20 b of the input side member 20.

  The input side member 20 is made of the same material as the substrate 11. That is, the input side member 20 is comprised by the silicon substrate, the glass substrate, the ceramic substrate, the LN substrate etc., for example. The input side member 20 may not be made of the same material as the substrate 11, but is preferably made of the same material. By making the input side member 20 and the substrate 11 the same material, the strength and thermal expansion coefficient of the input side member 20 and the substrate 11 can be made uniform.

  The output side member 21 is provided at an end portion on the output side (+ X side) on the cladding layer 12. In the present embodiment, the output side member 21 has a rectangular parallelepiped shape. The output side surface 21 b of the output side member 21 is included in the output surface 15. That is, the output side member 21 is provided such that the output side surface 21 b is flush with the output side surface 11 b of the substrate 11. A reflection film (reflection element, suppression means) 23 is formed on the input side surface 21 a of the output side member 21.

  Similarly to the input side member 20, the output side member 21 is made of the same material as the substrate 11. That is, the output side member 21 is composed of, for example, a silicon substrate, a glass substrate, a ceramic substrate, an LN substrate, or the like.

  The input side member 20 and the output side member 21 have a function of facilitating connecting the optical fiber 30 and the optical fiber 31 to the optical waveguide 13. That is, the input side surface 20 a of the input side member 20 can expand the input surface 14 of the optical waveguide device 10, and the entire joining end surface of the optical fiber 30 can be joined to the input surface 14. Thereby, the adhesive strength between the optical fiber 30 and the input surface 14 can be increased. Further, the output side surface 21 b of the output side member 21 can expand the output surface 15 of the optical waveguide device 10, and the entire joining end surface of the optical fiber 31 can be joined to the output surface 15. Thereby, the adhesive strength between the optical fiber 31 and the output surface 15 can be increased.

  The optical fiber 30 is a cable for transmitting an optical signal. As shown in FIGS. 2 and 3, the optical fiber 30 includes a core 32 that propagates light and a clad 33 provided outside the core 32. As shown in FIG. 3, the optical fiber 30 is connected to the input surface 14 such that the core 32 overlaps the input-side end portion 13 a of the optical waveguide 13 in front view (YZ plane view).

  The diameter of the optical fiber 30 is, for example, about 125 μm. The diameter of the core 32 is, for example, about 10 μm. The core 32 and the clad 33 are made of, for example, quartz glass or plastic.

  The optical fiber 31 is a cable similar to the optical fiber 30. As illustrated in FIGS. 2 and 3, the optical fiber 31 includes a core 34 and a clad 35. The optical fiber 31 is connected to the output surface 15 in the same manner as the optical fiber 30.

  The reflective film 22 is formed on the entire output side surface 20 b of the input side member 20. The reflective film 23 is formed on the entire input side surface 21 a of the output side member 21. The reflective film 22 and the reflective film 23 have a property of reflecting at least a part of light emitted from the optical fiber 30. The reflective film 22 and the reflective film 23 are made of, for example, gold, silver, or tin.

  According to the present embodiment, since the reflective film 22 and the reflective film 23 are provided, it is possible to suppress the light that has not been input to the optical waveguide 13 from reaching the output surface 15, and the output side end 13 b of the optical waveguide 13. It is easy to connect the optical fiber 31. Details will be described below.

FIG. 4 is a partially enlarged side sectional view of the optical waveguide device 10.
As shown in FIG. 4, light L is input from the core 32 of the optical fiber 30 to the optical waveguide 13 formed in the cladding layer 12. At this time, since the diameter of the optical waveguide 13 is smaller than the diameter of the core 32, non-input light Le that is not input to the optical waveguide 13 is generated. The non-input light Le enters the input side member 20 and the substrate 11 and proceeds to the output side (+ X side). And when the reflective film is not provided in the optical waveguide device, the non-input light Le may be emitted from the output surface of the optical waveguide device.

  In the following description, the non-input light Le refers to the output surface of the optical waveguide device when there is no suppression means such as the reflective films 22 and 23 of the present embodiment, among the light that is not input to the optical waveguide 13. In particular, it means the light emitted from.

  FIG. 5 is a side sectional view of the optical waveguide device 110 in which no reflective film is provided. FIG. 6 is a rear view of the optical waveguide device 110. In FIG. 6, the optical fiber 31 is omitted. The optical waveguide device 110 has the same configuration as the optical waveguide device 10 except that the reflective film is not provided.

  As shown in FIG. 5, since the reflective film is not formed on the input side member 20 and the output side member 21 of the optical waveguide device 110, at least a part of the non-input light Le described above is included in the input side member 20. Through the output side member 21. The non-input light Le incident on the output side member 21 is emitted from the output surface 15, more specifically, from the output side surface 21 b of the output side member 21. As a result, a large number of light source images Lm are visually recognized on the output surface 15 as shown in FIG.

  Here, although the details of the principle by which the non-input light Le emitted from the output side member 21 forms a large number of light source images Lm are unknown, it is considered to be based on the following principle. That is, as shown in FIG. 5, the non-input light Le incident on the output side member 21 is multiple-reflected in the output side member 21, and as a result, the lights interfere with each other and the intensity of the light is generated. As a result, as shown in FIG. 6, it is considered that a large number of light source images Lm, which are portions where multiple reflected lights interfere and strengthen each other, are visually recognized on the output surface 15. In some cases, it is also conceivable that the non-input light Le is reflected multiple times in the input side member 20 and affects the formation of a large number of light source images Lm on the output surface 15.

  As described above, in the optical waveguide device 110 in which the reflective film is not provided, a large number of light source images Lm are visually recognized on the output surface 15, so that the light at the output side end portion 13 b of the optical waveguide 13 is difficult to distinguish. Thus, there is a problem that it is difficult to connect the optical fiber 31 to the output side end portion 13 b of the optical waveguide 13.

  The above problem is caused when the waveguide shape of the input-side optical fiber 30 and the shape of the optical waveguide 13 on the substrate 11 are different, that is, the mode field of light propagating through the input-side optical fiber 30 and the substrate 11. This occurs when the mode field of light propagating through the optical waveguide 13 is different. In particular, the above-described problem occurs remarkably when the length of the optical waveguide device is shortened. This is because the non-input light Le is less attenuated before reaching the output surface, and the intensity of the non-input light emitted from the output surface is high.

  On the other hand, according to the present embodiment, since the reflective film 22 and the reflective film 23 are provided on the input side member 20 and the output side member 21, respectively, as shown in FIG. It is reflected by the reflective film 22 and the reflective film 23 and is prevented from reaching the output surface 15. As a result, it is possible to suppress the non-input light Le from being emitted from the output surface 15, and it is easy to determine the position of the output side end portion 13 b of the optical waveguide 13. Therefore, according to the present embodiment, it is possible to obtain an optical waveguide device in which it is easy to optically connect the optical fiber 31 to the output side end portion 13b of the optical waveguide 13 during manufacturing.

  In the present embodiment, the following configuration may be employed.

  In the embodiment described above, the reflective film 22 is formed on the entire output side surface 20b of the input side member 20, and the reflective film 23 is formed on the entire input side surface 21a of the output side member 21, It is not limited to this. In the present embodiment, for example, the reflective film 22 may be formed on a part of the output side surface 20 b of the input side member 20 within a range where at least a part of the non-input light Le is incident on the reflective film 22. Alternatively, the reflection film 23 may be formed on a part of the input side surface 21 a of the output side member 21 within a range where at least a part of the non-input light Le is incident on the reflection film 23.

In the embodiment described above, the input side member 20 and the output side member 21 are provided with the reflective film 22 and the reflective film 23, but either one of the reflective films is provided. It does not have to be.
Further, the reflective film 22 and the reflective film 23 may transmit a part of incident light.

  In this embodiment, an absorption film (absorption element, suppression means) may be provided instead of the reflection films 22 and 23. The absorption film absorbs at least part of incident light. Thereby, it is possible to suppress the non-input light Le from reaching the output surface 15.

In this embodiment, instead of the reflection films 22 and 23, a scattering film (light scattering element, suppression means) may be provided. The scattering film scatters incident light. Thereby, the non-input light Le is scattered and the intensity is weakened, and the non-input light Le can be prevented from reaching the output surface 15. The scattering film is not particularly limited as long as it has a property of scattering light. In the present embodiment, as the configuration of the scattering film, for example, a configuration in which fine particles having different refractive indexes are included in the transparent resin can be employed.
The scattering film may be provided only on either the input side member 20 or the output side member 21. In particular, since scattered light loses directivity and the light intensity per unit area decreases, it is effective to provide the scattering film on the input side member 20 far from the output surface 15.

  In the present embodiment, instead of the scattering film, the non-input light Le is scattered by processing the output side surface 20b of the input side member 20 and the input side surface 21a of the output side member 21 into an uneven shape. It is good. The concavo-convex shape is, for example, a grain by sandblasting, a slit shape, or the like. For example, in the case where the input side member 20 and the output side member 21 are cut out from the base material and manufactured, the output side surface 20b of the input side member 20 and the input side surface 21a of the output side member 21 are in a roughly cut state. By doing so, an uneven shape may be formed.

  In the embodiment described above, the optical waveguide 13 is a straight type optical waveguide formed linearly, but is not limited thereto. In the present embodiment, for example, the optical waveguide may have a curvature or a branched shape. In the present embodiment, the optical waveguide may be, for example, a Mach-Zehnder interferometer type optical waveguide.

In the present embodiment, the input-side optical fiber 30 and the output-side optical fiber 31 do not have to be aligned.
In the embodiment described above, only one output-side optical fiber 31 is provided. However, the present invention is not limited to this. In the present embodiment, for example, when the optical waveguide 13 is branched and a plurality of output side end portions 13b are provided on the output surface 15, a plurality of optical fibers 31 corresponding to the number of output side end portions 13b are provided. The configuration may be such that the output surface 15 is connected.

In the embodiment described above, the optical fiber 30 is directly connected to the optical waveguide 13 and the light L from the optical fiber 30 is input to the optical waveguide 13. However, the present invention is not limited to this. In the present embodiment, for example, a lens may be provided between the optical fiber 30 and the optical waveguide 13, and the light L from the optical fiber 30 may be input to the optical waveguide 13 through the lens.
In this case, the non-input light Le is generated when the mode field of the light collected by the lens is different from the mode field of the light propagating through the optical waveguide 13 on the substrate 11 or when the coupling of light is insufficient. Occur.

  In the present embodiment, a plurality of polymer materials may be coated on the substrate 11 to form a laminated structure optical waveguide.

In the embodiment described above, an organic polymer is used as the optical waveguide, but the present invention is not limited to this. In the present embodiment, for example, the substrate 11 may be an LN substrate, and an optical waveguide may be formed by thermally diffusing Ti or the like from the surface of the LN substrate.
The substrate 11 for forming the optical waveguide 13 may be other than an LN substrate as long as it has an electro-optic effect. For example, PLZT ((Pb, La) (Zr, Tr) O ₃ ) or LT (LiTaO) A substrate using ₃ ) or the like as a forming material may be used.

In the present embodiment, a substrate having an electrooptic effect, such as an LN substrate having a thickness of about 10 μm, on which an optical waveguide is further formed may be bonded to the substrate 11. In this case, the substrate 11 may be made of LN, silicon, glass, ceramics, or the like.
The substrate on which the optical waveguide bonded on the substrate 11 is formed may be other than an LN substrate as long as it has an electro-optic effect. For example, PLZT ((Pb, La) (Zr, Tr) O ₃ ), LT (LiTaO ₃ ), or the like may be used as a forming material.

(Second Embodiment)
The second embodiment differs from the first embodiment in that an absorption element is provided on the substrate.
In the following description, the same components as those in the above embodiment may be omitted by appropriately attaching the same symbols.

FIG. 7 is a side sectional view showing the optical waveguide device 210 of the second embodiment.
As shown in FIG. 7, the optical waveguide device 210 of the present embodiment has a recess 224 formed in a substrate 211, and an absorbent (absorbing element, suppression means) 225 is filled in the recess 224.

  The recess 224 is a part in the width direction (Y-axis direction) of the substrate 211 or the thickness direction (Z-axis direction) of the substrate 211 within a range where at least a part of the non-input light Le enters the recess 224. It may be formed in the whole or may be formed over the whole. The position of the recess 224 in the length direction (X-axis direction) on the substrate 211 is not particularly limited as long as the non-input light Le is incident on the inside of the recess 224. In the present embodiment, for example, the recess 224 is formed at the center in the length direction (X-axis direction) of the substrate 211.

The absorber 225 has a property of absorbing at least a part of incident light.
The material of the absorbent 225 is not particularly limited as long as it has a property of absorbing light, and any known material that absorbs light, such as carbon black, may be used.

  Moreover, in the above embodiment, although the structure which provides the function for suppressing non-input light Le reaching | attaining the output surface 15 was demonstrated, in this embodiment, the input side member 20 and the output side member 21 are provided. Alternatively, the anti-reflection film may be formed on the output surface 15 so as to actively transmit the non-input light Le to the output surface 15. Thereby, since multiple reflection at the input side member 20 and the output side member 21 is suppressed, it is difficult to generate a large number of light source images Lm as shown in FIG. An optical fiber or the like can be easily connected to the side end portion 13b. As the antireflection film, a dielectric multilayer film or the like can be used.

  According to this embodiment, since the non-input light Le emitted from the optical fiber 30 and incident on the substrate 211 is absorbed by the absorbent 225, the non-input light Le is output to the output surface 215, more specifically, the substrate 211. Can be prevented from reaching the output side surface 211b. Thereby, according to this embodiment, an optical waveguide device in which an optical fiber can be easily connected to the output end side of the optical waveguide 13 at the time of manufacture is obtained.

  In the present embodiment, the following configuration may be employed.

  In the present embodiment, the absorbent 225 may not be filled in the concave portion 224 or may be provided in a part. In the present embodiment, for example, an absorbent film may be formed by applying the absorbent 225 to the inner wall of the recess 224.

Moreover, in this embodiment, the structure which provides the reflection film which reflects light in the inside of the recessed part 224 or an inner wall may be sufficient.
Further, in the present embodiment, when the refractive index of the substrate 211 is sufficiently larger than that of air, a configuration in which only the recess 224 is formed in the substrate 211 may be employed. In this case, since the non-input light Le is refracted greatly when the non-input light Le is emitted from the substrate 211 into the recess 224, that is, in the air, it can be prevented from entering the substrate 211 again. Moreover, since the refractive index difference between the air and the substrate 211 is large, the reflectance at the boundary surface between the air and the substrate 211 is increased, and the boundary surface functions as a reflecting portion. As a result, the non-input light Le can be prevented from reaching the output surface 215. That is, the recess 224 functions as a suppression unit that suppresses the non-input light Le from reaching the output surface 215.

  In the present embodiment, the light incident on the recess 224 may be scattered by forming an uneven shape on the inner wall of the recess 224.

(Third embodiment)
The third embodiment is different from the first embodiment in that an absorbent is filled in the recesses formed in the input side member and the output side member instead of the reflective film.
In the following description, the same components as those in the above embodiment may be omitted by appropriately attaching the same symbols.

FIG. 8 is a side sectional view showing the optical waveguide device 310 of the present embodiment.
As shown in FIG. 8, the optical waveguide device 310 of this embodiment includes an input side member 320 and an output side member 321.
The input side member 320 has a recess 322 that opens to the substrate 11 side (−Z side). The output side member 321 has a recess 324 that opens to the substrate 11 side (−Z side). The side view (ZX plane view) shape of the recessed part 322 and the recessed part 324 is not specifically limited, In this embodiment, it is a rectangular shape, for example. The recess 322 and the recess 324 are formed in a part of the width direction (Y-axis direction) of the optical waveguide device 310 within a range where at least a part of the non-input light Le enters the recess 322 and the recess 324. It may be formed over the whole.

  The concave portion 322 of the input side member 320 is filled with an absorbent (absorbing element, suppressing means) 323. The recess (324) of the output side member 321 is filled with an absorbent (absorbing element, suppressing means) 325. The absorbent 323 and the absorbent 325 are the same as the absorbent 225 in the second embodiment, and have a property of absorbing at least part of incident light.

  The outer shape, arrangement, and the like of the input side member 320 and the output side member 321 are the same as those of the input side member 20 and the output side member 21 of the first embodiment.

  According to the present embodiment, it is possible to suppress non-input light from being absorbed by the absorbent 323 and the absorbent 325 and reaching the output surface 315. Thereby, according to this embodiment, an optical waveguide device in which an optical fiber can be easily connected to the output end side of the optical waveguide 13 at the time of manufacture is obtained.

  In the present embodiment, the following configuration may be employed.

  In the present embodiment, the absorbent 323 and the absorbent 325 may not be filled in the recesses 322 and the recesses 324, or may be provided in part. In the present embodiment, for example, the absorbent 323 and the absorbent 325 may be applied to the inner walls of the recess 322 and the recess 324 to form an absorption film.

In the present embodiment, the absorbent 323 and the absorbent 325 may be composed of different substances.
In the present embodiment, instead of the absorbent 323 and the absorbent 325, a substance that reflects light may be provided in at least a part of the recesses 322 and 324.

  In the embodiment described above, the input side member 320 and the output side member 321 are formed with the concave portion 322 and the concave portion 324 that open to the substrate 11 side (−Z side), but the present invention is not limited thereto. In the present embodiment, for example, a closed space may be formed inside the input side member 320 and the output side member 321. In this case, the closed space is filled with an absorbent or a reflective agent.

  In the present embodiment, for example, a through-hole penetrating in the thickness direction (Z-axis direction) of the optical waveguide device 310 may be formed in the input side member 320 and the output side member 321.

  In the present embodiment, only one of the recess 322 and the recess 324 may be formed.

(Fourth embodiment)
The fourth embodiment differs from the first embodiment in that slopes are formed on the input side member and the output side member.
In the following description, the same components as those in the above embodiment may be omitted by appropriately attaching the same symbols.

9 and 10 are diagrams showing the optical waveguide device 410 of the present embodiment. FIG. 9 is a perspective view. FIG. 10 is a plan view.
As shown in FIGS. 9 and 10, the optical waveguide device 410 of the present embodiment includes an input side member (optical element, suppression means) 420, an output side member (optical element, suppression means) 421, and a reflective film (reflection). Element, suppression means) 424 and a reflective film (reflection element, suppression means) 425.

  The input side member 420 is inclined by about 45 ° around the normal axis (Z axis) of the main surface of the substrate 11 with respect to the light input from the optical fiber 30, more specifically, the optical path direction of the non-input light Le. An optical element having an inclined surface 422. The inclined surface 422 faces the side surface side (−Y side) of the optical waveguide device 410. A reflective film 424 is formed on the slope 422.

  The output-side member 421 is inclined by about 45 ° around the normal axis (Z axis) of the main surface of the substrate 11 with respect to the light input from the optical fiber 30, more specifically, the optical path direction of the non-input light Le. This is an optical element having a slope 423. The inclination direction of the inclined surface 423 with respect to the non-input light Le is the same as that of the inclined surface 422. The slope 423 faces the side surface side (+ Y side) of the optical waveguide device 410. A reflective film 425 is formed on the slope 423.

  The reflective film 424 and the reflective film 425 are the same as the reflective film 22 and the reflective film 23 of the first embodiment, and have a property of reflecting at least a part of the non-input light Le as shown in FIG. According to this embodiment, since the reflective film 424 and the reflective film 425 are formed on the slope 422 and the slope 423, at least part of the non-input light Le incident on the reflective film 424 and the reflective film 425 is in the optical path direction. Is bent by about 90 ° and reflected. In the present embodiment, the non-input light Le incident on the reflective film 424 and the non-input light Le incident on the reflective film 425 are reflected on the same side (+ Y side). Thereby, the non-input light Le is suppressed from reaching the output surface 415.

  According to this embodiment, since the reflective film 424 and the reflective film 425 are provided on the slope 422 and the slope 423, the non-input light Le is suppressed from reaching the output surface 415. Thereby, according to this embodiment, an optical waveguide device in which an optical fiber can be easily connected to the output end side of the optical waveguide 13 at the time of manufacture is obtained.

  In the present embodiment, the following configuration can also be adopted.

  In the present embodiment, the reflective film 424 and the reflective film 425 may not be provided. In this case, the non-input light Le is refracted when entering the inclined surfaces 422 and 423, and the non-input light Le can be prevented from reaching the output surface 415. In the present embodiment, the angle at which the inclined surface 422 and the inclined surface 423 are formed may be adjusted so that the incident non-input light Le is totally reflected.

  In the above-described embodiment, the inclined surface 422 and the inclined surface 423 face the side surface side of the optical waveguide device 410 (± Y side: when the Z axis is the rotation axis), but are not limited thereto. . In the present embodiment, for example, the inclined surface may be formed so as to face the upper surface side (+ Z side) or the bottom surface side (−Z side).

In the present embodiment, only one of the slope 422 and the slope 423 may be formed.
In the present embodiment, the angles of the slope 422 and the slope 423 may be different from each other.

  L: Light, Le: Non-input light, 10, 210, 310, 410: Optical waveguide device, 11, 211: Substrate, 13: Optical waveguide, 13a: Input side end, 13b: Output side end, 14: Input 15, 215, 315, 415... Output surface, 20, 320... Input side member, 420... Input side member (optical element, suppression means), 20 a. , 421 ... output side member (optical element, suppression means), 21a ... output side surface (one side face), 22, 23, 424, 425 ... reflective film (reflection element, suppression means), 225, 323, 325 ... absorbent ( Absorbing element, suppression means), 422, 423 ... slope

Claims (7)

A substrate,
An optical waveguide formed on the substrate;
Of the light input to the input surface provided with the input side end of the optical waveguide, non-input light not input to the optical waveguide reaches the output surface provided with the output side end of the optical waveguide. Suppression means for suppressing this,
An optical waveguide device comprising: On the optical waveguide, an output side member having one side surface included in the output surface is provided,
The optical waveguide device according to claim 1, wherein the suppression unit is provided on the output side member.   The optical waveguide device according to claim 1, wherein the suppression unit is a reflective element that reflects at least a part of the non-input light.   The optical waveguide device according to claim 1, wherein the suppression unit is a light scattering element that scatters at least a part of the non-input light.   The optical waveguide device according to claim 1, wherein the suppression unit is an absorption element that absorbs at least a part of the non-input light.   The optical waveguide device according to claim 1, wherein the suppression unit is an optical element having a slope inclined with respect to an optical path direction of the non-input light. On the optical waveguide, an input side member having one side surface included in the input surface is provided,
The optical waveguide device according to claim 1, wherein the suppression unit is provided in the input side member.

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