JP2010169755A - Optical path change mirror - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical path change mirror for which selection of materials is easy, and the manufacturing procedure of which is simple. <P>SOLUTION: The optical path change mirror is composed of a block 2 formed of an optically transparent material, and the block 2 is provided with: a flat bottom face 3 to be in contact with a substrate surface; an inclined face 4 inclined with respect to the bottom face 3 for the purpose of reflecting light incident in parallel with the bottom face 3 in the direction of the bottom face 3; and a counter face 5 for an optical transmitter opposite the optical transmitter. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical path conversion mirror that allows easy material selection and a simple manufacturing procedure.

  A member that realizes the optical wiring and the electrical wiring with an integrated substrate is called a photoelectric composite wiring.

  As shown in FIG. 6, in the conventional photoelectric composite wiring 61, a light-emitting element whose upper surface is a light-emitting surface or a light-receiving element 63 whose upper surface is a light-receiving surface is mounted on the lower surface of a substrate 62. The body 64 is disposed on the upper surface side of the substrate 62. Only the case of optical reception will be described below.

  In order to direct the emitted light from the optical transmission body 64 arranged on the upper surface side of the substrate 62 toward the lower surface of the substrate 62, it is necessary to mount the optical path conversion mirror 65 on the upper surface of the substrate 62.

  The optical path conversion mirror 65 includes a flat bottom surface for contacting the substrate surface, an inclined surface 66 inclined with respect to the bottom surface for reflecting light incident parallel to the bottom surface in the direction of the bottom surface, and the inclined surface. An optical transmission body facing surface (not shown) located at a predetermined distance or more away from the light incident direction from 66, and a core 67 that guides the light from the opposing surface for the optical transmission body to the reflection surface 66 so as not to diffuse. Is provided. The end surface of the optical transmission body 64 is in contact with the opposing surface for the optical transmission body.

JP 2006-301610 A

  The conventional optical path conversion mirror 65 has a core 67. The core 67 is a portion having a relatively high refractive index with respect to the cladding that is the surrounding portion. By providing the core 67, incident light incident on the optical transmission surface of the optical path conversion mirror 65 from the optical transmission body 64 is transmitted while being confined in the core 67, and attenuated by diffusion to the inclined surface 66. Reach without.

  In order to form the core 67, it is necessary to combine a core material having a high refractive index and a cladding material having a low refractive index. After forming the lower cladding, the core 67 is formed on the lower cladding, and then the upper cladding is formed on the core 67. Thus, light can be confined by superimposing materials having different refractive indexes.

  The conventional optical path conversion mirror 65 requires a plurality of types of materials having different refractive indexes in order to form the core 67. Even if you want to select a material other than the refractive index, for example, considering the hardness, the refractive index condition cannot be excluded, so you must consider combining the refractive index and hardness of multiple types of materials. Is constrained.

  In addition, since the conventional optical path conversion mirror 65 forms the core 67, the manufacturing procedure is in a plurality of stages and is complicated. Furthermore, since it is necessary for the core 67 to face the optical transmission body 64 so that the optical axis does not shift, it is necessary to align the core when manufacturing the core, and the manufacturing procedure of the optical path conversion mirror 65 is further complicated. Become.

  Thus, the conventional optical path conversion mirror 65 requires a plurality of materials, and the manufacturing procedure is complicated.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical path conversion mirror that solves the above-described problems and that allows easy material selection and a simple manufacturing procedure.

  In order to achieve the above object, the present invention is directed to emitting light from an optical transmission body mounted on one side of a substrate and extending along the one side of the substrate toward the opposite surface of the substrate, or the opposite surface of the substrate. In the optical path conversion mirror for making the light from the light incident on the optical transmission body, the optical path conversion mirror comprises a block formed of a material transparent to the light, and the block includes a flat bottom surface for contacting the substrate surface, The light incident parallel to the bottom surface is reflected in the direction of the bottom surface, or the inclined surface inclined with respect to the bottom surface to reflect the light incident from the bottom surface parallel to the bottom surface, facing the optical transmission body And an opposing surface for the optical transmission body.

  The block may be a single block having a uniform refractive index.

  You may provide the convex part extended to the predetermined distance in parallel with the said board | substrate from the said opposing surface for optical transmission bodies.

  The optical transmission body may be an optical fiber.

  The optical transmission body may be a waveguide core.

  The distance from the optical transmission body to the opposing surface for the optical transmission body may be 150 μm or less.

  The present invention exhibits the following excellent effects.

  (1) Material selection is easy.

  (2) The manufacturing procedure is simple.

(A), (b) is a perspective view of the optical path conversion mirror which shows one Embodiment of this invention. (A), (b) is a perspective view of the optical path conversion mirror which shows other embodiment of this invention. (A)-(d) is a perspective view of the optical path conversion mirror which shows embodiment of the optical transmission body of this invention. It is a side view of the photoelectric composite wiring using the optical path conversion mirror of this invention. (A), (b) is a perspective view of the optical path conversion mirror which shows the modification of this invention. It is a side view of the photoelectric composite wiring using the conventional optical path conversion mirror.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings (the structure is the same in both cases of optical transmission and optical reception, so only the case of optical reception will be described).

  As shown in FIGS. 1 (a) and 1 (b), the optical path conversion mirrors 11 and 12 according to the present invention are mounted on one side of a substrate (see FIG. 4) 42 and run along one side of the substrate. An optical path conversion mirror for emitting incident light from an optical transmission body toward the opposite surface of the substrate, comprising a block 2 formed of a transparent material, and a flat bottom surface 3 for contacting the substrate surface, An inclined surface 4 that is inclined with respect to the bottom surface 3 in order to reflect light incident in parallel with the bottom surface 3 in the direction of the bottom surface 3, and a light transmission body facing surface 5 that faces the light transmission body. It is.

  The optical path conversion mirror 11 in FIG. 1A is suitable for a case where there is one optical transmission body (optical fiber, waveguide core) to be applied. The optical path conversion mirror 12 in FIG. 1B is suitable for a case where two optical transmission bodies are applied. Hereinafter, those suitable for one optical transmission body and those suitable for two are described together.

  The optical path conversion mirrors 11 and 12 of the present invention are preferably composed of a block 2 made of a material transparent to the light, and a single block 2 having a uniform refractive index. As illustrated, the optical path conversion mirrors 11 and 12 are hexahedral blocks 2. That is, the optical path conversion mirrors 11 and 12 connect the bottom surface 3 which is flat and rectangular, the rectangular top surface 6 which is parallel to the bottom surface 3 and has a short side shorter than the bottom surface 3, and the bottom surfaces of the bottom surface 3 and the top surface 6 to each other. 2, the opposite sides 5 of the optical transmission body perpendicular to the bottom surface 3, and the other long sides of the bottom surface 3 and the upper surface 6 are connected to each other. And an inclined surface 4 having an inclination of 45 ° with respect to the connecting bottom surface 3.

  The material of the optical path conversion mirrors 11 and 12 may be anything as long as it is transparent to the light used for optical communication. For example, resin, glass, or the like conventionally used for the core or cladding of the optical waveguide. Available.

  When members previously formed as blocks are used for the optical path conversion mirrors 11 and 12, the optical path conversion mirror 1 can be manufactured by bonding and fixing to the substrate surface according to the position of the optical transmission body. Further, the optical path conversion mirrors 11 and 12 are manufactured by forming blocks directly on the substrate surface from the varnish-like resin using photolithography or a mold and forming inclined surfaces using a 90 ° V-shaped dicing blade. can do.

  In the optical path conversion mirrors 11 and 12 of the present invention, the distance from the end surface of the optical transmission body to the optical transmission body facing surface 5 is equal to or less than the distance at which the diffusion of light is a predetermined amount. The distance from the end surface of the optical transmission body to the opposing surface 5 for the optical transmission body is a distance along the optical path.

  2A and 2B show optical path conversion mirrors 21 and 22 according to other embodiments.

  As shown in FIG. 2A and FIG. 2B, the optical path conversion mirrors 21 and 22 according to other embodiments of the present invention include light path conversion mirrors 11 and 12 shown in FIG. Convex portions 8 are provided that extend from the transmitting body facing surface 5 to a predetermined distance in the light incident direction. The convex portions 8 are provided in a space that is not occupied by the optical transmission body (see FIG. 3) connected to the opposing surface 5 for the optical transmission body, and are provided at a plurality of locations in the width direction at intervals substantially equal to the width of the optical transmission body.

  The convex portion 8 serves as a guide for guiding and aligning the optical transmission body and as a fixing member for the optical transmission body when an assembly is manufactured by combining the optical path conversion mirrors 21 and 22 and the optical transmission body. It is.

  The convex portion 8 is integrally formed simultaneously with the block 2 as a part of the block 2. Therefore, like the optical path conversion mirrors 11 and 12, the optical path conversion mirrors 21 and 22 are composed of a single block 2 having a uniform refractive index.

  FIG. 3A to FIG. 3D show an embodiment of an optical transmission body.

  As shown in FIGS. 3A and 3C, the optical transmission body 31 is realized by an optical fiber 32. The optical fiber 32 is inserted between the convex portion 8 of the optical path conversion mirrors 21 and 22 in FIG. The end face of the optical fiber 32 is brought into contact with the opposing surface 5 for the optical transmission body.

  Then, the convex part 8 and the optical fiber 32 are fixed using an adhesive agent. In order to suppress the reflection of light, it is desirable that the refractive index of the adhesive is close to or intermediate between the refractive index of the mirror member and the optical fiber material.

  As shown in FIGS. 3B and 3D, the optical transmission body 31 is realized by a waveguide core 33. The waveguide core 33 is provided at a right angle with respect to the optical transmission surface 5 of the optical path conversion mirrors 11 and 12 of FIG. The end face 34 of the waveguide core 33 is brought into contact with the facing surface 5 for the optical transmission body. In this figure, the waveguide core 33 is drawn away from the optical path conversion mirrors 11 and 12 in order to show the end face 34.

  The waveguide core 33 can be made of resin using photolithography or a mold. At this time, the optical transmission surface opposing surface 5 of the optical path conversion mirrors 11 and 12 and the waveguide core end face 34 are formed with a gap therebetween.

  On the substrate, a lower clad of the waveguide, a block to be the optical path conversion mirrors 11 and 12, and the waveguide core 33 are arranged, and the upper clad is formed so as to cover the waveguide core 33. At this time, it is desirable that the upper clad does not cover the block to be the optical path conversion mirrors 11 and 12, but in this case, after forming the upper clad, the block is cut together with the upper clad at a predetermined position by a 90 ° V-shaped dicing blade. Thus, an inclined surface can be formed.

  In addition, when the inclined surfaces of the optical path conversion mirrors 11 and 12 are formed before the upper clad is formed, the upper clad material is formed so as not to cover the inclined surface, so that the waveguide structure is maintained while the inclined surface is maintained. Can be produced. Alternatively, the function of the mirror can be maintained by attaching a metal film to the inclined surface in advance.

  In particular, when the optical transmission body is a waveguide, the optical path conversion mirrors 11 and 12 and the end face of the optical transmission body are formed with a space therebetween. When the waveguide is manufactured by photolithography, a mold, or the like, it is difficult to manufacture the waveguide by making contact with the block for the optical path conversion mirrors 11 and 12, and therefore, the end surface of the optical transmission body from the opposing surface for the optical transmission body. Will be spaced apart. If this distance is too large, leakage light is generated between the optical transmission body and the optical path conversion mirrors 11 and 12, resulting in loss.

  This loss was simulated by the beam propagation method. As a simulation model, the refractive index of the waveguide core 33 is 1.55, the length of one side in the cross section of the waveguide core 33 is 50 μm, the refractive index of the cladding is 1.50, and the inclined surfaces 4 of the optical path conversion mirrors 11 and 12 The width in the direction perpendicular to the tilt direction was 80 μm. The light source was a light emitting wavelength of 850 μm which is the emission wavelength of a surface emitting laser (VCSEL), and a 3.1 μm point light source having a spread angle equivalent to that of the VCSEL was used. Further, since the mode state of light propagating through the waveguide core 33 depends on the length of the waveguide core 33, the length of the waveguide core 33 is changed in the range of 2.5 to 5.0 mm. Done in dimension.

  As a result of the simulation, the rate at which the amount of light emitted from the end face of the optical transmission body 31 is held on the inclined surface 4 of the optical path conversion mirrors 11 and 12 (light amount holding rate) depends on the mode state of light. ) Depending on the length of the waveguide core 33 and the width of the inclined surface 4 of the optical path conversion mirrors 11 and 12 in the direction perpendicular to the inclined direction, the length of the waveguide core 33 is in the range of 2.5 to 5.0 mm. If the distance from the end face of the optical transmission body 31 to the inclined surface 4 of the optical path conversion mirrors 11 and 12 is 100 μm, the light quantity retention rate is maintained at 97% or more, and the optical path conversion mirrors 11 and 12 It was confirmed that the light reached the inclined surface 4 satisfactorily. When the distance from the end face of the optical transmission body 31 to the inclined surface 4 of the optical path conversion mirrors 11 and 12 is 200 μm, the light quantity retention rate is maintained around 90%, but from the end face of the optical transmission body 31 to the optical path conversion mirror 11. , 12 when the distance to the inclined surface 4 is 300 μm, it has been confirmed that the light quantity retention rate falls to about 80%.

  Further, even when the length of the waveguide core 33 is changed in the range of 2.5 to 5.0 mm, when the width in the direction perpendicular to the inclined direction of the inclined surface 4 of the optical path conversion mirrors 11 and 12 is 70 μm, The distance from the inclined surface 4 of the optical path conversion mirrors 11 and 12 to the end surface of the optical transmission body 31 is 100 μm, and a light quantity of 95% or more is maintained, and the light reaches the inclined surfaces of the optical path conversion mirrors 11 and 12 satisfactorily. ing. When this distance is 200 μm, the amount of light is maintained at about 85%, but at 300 μm, it falls to about 70%.

  Further, even when the length of the waveguide core 33 is changed in the range of 2.5 to 5.0 mm, when the width in the direction perpendicular to the inclined direction of the inclined surface 4 of the optical path conversion mirrors 11 and 12 is 60 μm, The distance from the inclined surface 4 of the optical path conversion mirrors 11 and 12 to the end surface of the optical transmission body 31 is 100 μm, and a light amount of 88% is maintained, and the light reaches the inclined surfaces of the optical path conversion mirrors 11 and 12 well. Yes. When this distance is 200 μm, the amount of light falls to around 70%, and at 300 μm, it falls to about 60%.

  Further, even when the length of the waveguide core 33 is changed in the range of 2.5 to 5.0 mm, when the width in the direction perpendicular to the inclined direction of the inclined surface 4 of the optical path conversion mirrors 11 and 12 is 50 μm, When the distance from the inclined surface 4 of the optical path conversion mirrors 11 and 12 to the end face of the optical transmission body 31 is 100 μm, it is about 65 to 80%, and when it is 200 μm and 300 μm, the loss increases to around 55% and around 45%. Come.

  As a result of the simulation, when the optical transmission body is arranged, when the width in the direction perpendicular to the inclination direction of the inclined surface 4 of the optical path conversion mirrors 11 and 12 is 80 μm, the optical transmission bodies of the optical path conversion mirrors 11 and 12 are arranged. In the case where the distance to the opposing surface is 300 μm or less and the width in the direction perpendicular to the inclined direction of the inclined surface 4 of the optical path conversion mirror 1 is 70 μm, the distance of the optical path conversion mirrors 11 and 12 to the opposing surface for the optical transmission body is When the width in the direction perpendicular to the inclination direction of the inclined surface 4 of the optical path conversion mirrors 11 and 12 is 60 μm or less, the distance from the optical path conversion mirrors 11 and 12 to the opposing surface for the optical transmitter should be 150 μm or less. It was confirmed that a good light quantity retention rate (80% or more) could be maintained.

  When forming the inclined surfaces of the optical path conversion mirrors 11 and 12, it is necessary to keep the distance between the inclined surface and the opposing surface for the optical transmission body short. When this distance is long, light spreads in the members of the optical path conversion mirrors 11 and 12, and a large loss occurs when the light is received by the light receiving element after being reflected by the inclined surface. This distance is desirably 300 μm or less, and more preferably 100 μm or less. The distance in this case refers to the length of the line connecting the inclined surface and the opposing surface for the optical transmission body in the shortest time. If this distance is too small, it is difficult to produce an inclined surface.

  4 (a) and 4 (b) show a photoelectric composite wiring 41 configured by mounting the optical path conversion mirrors 21 and 22 of the present invention on a substrate. This figure shows a case where the optical element 43 is a light receiving element, and the configuration is the same even in the case of a light emitting element.

  4A and 4B, the optical path conversion mirrors 21 and 22 are mounted on the substrate 42 so that the flat bottom surface 3 is in contact with the upper surface of the substrate 42. A light receiving element 43 whose upper surface is a light receiving surface is mounted on the lower surface of the substrate 42.

  The operation of optical transmission in the photoelectric composite wiring 41 of FIG. 4 will be described.

  When the light transmitted through the optical transmission body 31 is emitted from the end face of the optical transmission body 31, the light enters the optical path conversion mirrors 21 and 22 from the opposing surface 5 for the optical transmission body. The light incident on the optical path conversion mirror 21 is reflected by the inclined surface 4 and the transmission direction is converted by 90 °. When it is assumed that the optical path in the optical transmission body 31 is at the center of the optical transmission body 31, the perpendicular line dropped from the point where this optical path intersects the inclined surface 4 of the optical path conversion mirrors 21 and 22 becomes the optical path by reflection. The light that has been reflected and whose transmission direction has been converted by 90 ° passes through the substrate 42, passes through the lower surface of the substrate 42, and enters the light receiving surface of the light receiving element 43.

  Since the optical path conversion mirrors 11, 12, 21, and 22 of the present invention are composed of a single block 2 having a uniform refractive index, only one kind of material may be used. Therefore, the material of the optical path conversion mirrors 11, 12, 21, 22 can be arbitrarily selected. For example, when a sufficiently hard material is desired so that the inclined surface 4 is not deformed, a sufficiently hard material can be used according to the request.

  Further, since the optical path conversion mirrors 11, 12, 21, and 22 are composed of a single block 2 having a uniform refractive index, the manufacturing procedure is simple. The optical path conversion mirrors 11, 12, 21, and 22 can be manufactured by a simple method such as integrally molding a resin with a single mold or cutting and molding a resin.

  Further, since the optical path conversion mirrors 11, 12, 21, and 22 do not have a core, the alignment of the core at the time of molding as in the prior art becomes unnecessary, and the manufacturing procedure is further simplified.

  In the optical path conversion mirrors 21 and 22 in FIG. 2, the convex portion 8 guides and aligns the optical transmission body 31 and also serves as a fixing member for the optical transmission body 31. Moreover, it can be set as the enclosure for filling with the fluid-like filler used as a waveguide core between the convex part 8 and the adjacent convex part 8. FIG. At this time, the refractive indexes of the optical path conversion mirrors 21 and 22 need to be smaller than the refractive index of the filler so as to form a waveguide structure.

  Next, a modified example of the present invention will be described.

  The optical path conversion mirrors 21 and 22 shown in FIG. 5 are obtained by adding a cover 51 to the optical path conversion mirrors 21 and 22 of FIG. The cover 51 is attached, for example, to cover the convex portion 8 from the end portion of the convex portion 8 (the far end from the inclined surface 4) to a predetermined distance. The cover 51 fixes the optical fiber 32 by covering and bonding the optical fiber 32 that is free from the substrate 42 (see FIG. 4).

11, 12, 21, 22 Optical path conversion mirror 2 Block 3 Bottom surface 4 Inclined surface 5 Opposing surface for optical transmission body 8 Convex

Claims (6)

Mounted on one side of the substrate and emits light from the optical transmission body along the one side of the substrate toward the opposite surface of the substrate, or allows light from the opposite surface of the substrate to enter the optical transmission body In the optical path conversion mirror for
It consists of a block made of a material transparent to the light,
The block has a flat bottom surface for contacting the substrate surface, and reflects light incident parallel to the bottom surface in the direction of the bottom surface or reflects light incident from the bottom surface parallel to the bottom surface. An optical path conversion mirror comprising an inclined surface that is inclined with respect to the bottom surface and an optical transmission body facing surface that faces the optical transmission body.   The optical path conversion mirror according to claim 1, wherein the block is a single block having a uniform refractive index.   3. The optical path conversion mirror according to claim 1, further comprising a convex portion extending to a predetermined distance in parallel with the substrate from the opposing surface for the optical transmission body.   4. The optical path conversion mirror according to claim 1, wherein the optical transmission body is an optical fiber.   4. The optical path conversion mirror according to claim 1, wherein the optical transmission body is a waveguide core.   The optical path conversion mirror according to claim 5, wherein a distance from the optical transmission body to the facing surface for the optical transmission body is 150 μm or less.

Images