JP4403245B2 - Optical module with surface light emitting element - Google Patents

Description

  The present invention relates to an optical module equipped with a surface light emitting / receiving element.

  In recent years, in addition to the conventional end face type, a surface type has been developed as a light emitting element used in an optical module. Here, “surface” means a surface of a silicon wafer on which elements are grown, and “end surface” means a surface obtained by cutting the wafer. FIG. 19 shows an example of an end face type light emitting / receiving element disclosed in Japanese Patent Laid-Open No. 10-160975 and used in the conventional optical module 7.

  In this conventional optical module 7, substantially half of the optical fiber 70 is embedded in a guide groove (V groove) 74 provided in the fiber block 72, and the rest is embedded in a guide groove (V groove) 78 provided in the silicon substrate 76. In particular, the end face 84 of the optical fiber 70 is disposed at a position facing the laser diode 82, that is, is an end face type.

  The application to various optical products has begun with respect to a surface light emitting / receiving element (VCSEL) which has been developed in recent years. Unlike the end face type, for example, the surface type can be manufactured with a high-density array arrangement with a simple element inspection process, and the light emitting surface and the electric input / output terminal surface can be formed on the same surface or the back surface. Therefore, it is very suitable for surface mounting. In addition, surface mounting using a surface light emitting / receiving element is a mounting method that is simple and suitable for automation.

Thus, elements of the surface type has many advantages over that of the end face type, which upon fixed in the usual manner in the substrate, perpendicular optical path to the substrate surface is formed. Therefore, if the direction of the optical path is not changed in the module in accordance with this vertical optical path, in other words, if an end face type light emitting / receiving element is used regardless of the vertical optical path, an optical transmission medium such as a fiber is used as the substrate. Protruding upwards can become an obstacle to high-density mounting. In the conventional end face type configuration, the optical fiber is used as a position guide to automatically adapt the optical axis between the light emitting / receiving element and the fiber, so that the degree of freedom in the direction perpendicular to the optical axis is increased. It is low and is not suitable for adjusting the optical axis in the height direction or converting the optical path by 90 degrees.

JP-A-10-160975

  The present invention has been made paying attention to such conventional problems, and provides an optical module that is compatible with surface-emitting light-emitting elements suitable for high-density mounting and that has a simple alignment process. The purpose is to do.

The present invention is an optical module including a surface light emitting and receiving element, wherein a support base having a stepped portion and an optical transmission medium disposed on a higher side than the support base are completely embedded in a recess of the groove In the state corresponding to the end face of the optical transmission medium arranged on the side higher than the support member and the block member fixed in the above-mentioned state, it is arranged on the lower side of the support table in a state where light can be received and emitted in the vertical direction. A surface-receiving / emitting element, and configured to perform optical transmission between the optical transmission medium and the surface-receiving / emitting element, and a high side of the support base is along an extending direction of the optical transmission medium. And the block member has a groove extending to a side closer to the surface light emitting / emitting element than the groove at a position corresponding to a groove provided on a higher side of the support base. That spans both the groove provided in the block member and the groove provided in the block member. The support base and the block member are positioned with respect to each other by sandwiching a guide member having a groove between them, and there are a plurality of grooves provided in the block member, all of which have the same depth. Or the shape of the optical transmission medium is extended in a recess of the groove provided in the block member to a side closer to the surface light emitting / emitting element than a groove provided on a higher side of the support base. The surface receiving light emitting element side is exposed and fixed and completely embedded therein, and the block member includes the optical transmission medium and the surface receiving light emitting element. It is characterized in that the end face is processed together with the optical transmission medium in the vicinity of the position where the optical transmission is performed .

  The end face may be processed to have an angle of about 45 degrees.

  In the optical module, there are a plurality of grooves provided in the support base, and they may all have the same depth or shape. In the optical module, there are a plurality of grooves provided in the block member, and they may all have the same depth or shape. Furthermore, the groove provided on the support base and the groove provided on the block member may all have the same depth or shape.

  In the optical module, the thermal expansion coefficient of the material of the support base may be substantially the same as that of the light emitting / receiving element.

  In the optical module, a plurality of the light emitting / receiving elements are arranged on the support base, some of the light receiving / emitting elements are light receiving parts, and some of the light receiving / emitting elements are light emitting parts. Alternatively, some oscillation wavelengths of the light receiving and emitting elements may be different from some other oscillation wavelengths of the light receiving and emitting elements.

In the optical module, the optical transmission medium may be accommodated in a connector integrated with a fiber support .

  According to the present invention, it is possible to realize an optical module on which surface-receiving / emitting optical elements are mounted by combining components having a simple structure with a simple alignment mechanism.

  1 to 11 show an optical module according to a first embodiment of the present invention. 1 is a perspective view of the optical module, FIG. 2 is a top view thereof, FIG. 3 is a side view thereof, FIG. 4 is a front view thereof, and FIG. 5 is a partially enlarged view of FIG. is there. 6 to 9 are diagrams showing in detail the components constituting the optical module. 10 is a cross-sectional view taken along line 10-10 of FIG. 4, and FIG. 11 is a partially enlarged view of FIG.

  The optical module 1 mainly includes a substrate (support base) 12 shown in FIGS. 6 and 7 and a guide block (block member) 11 shown in FIGS. 6 is a top view of the substrate 12, FIG. 7 is a side view thereof, FIG. 8 is a bottom view of the guide block 11, and FIG. 9 is a side view thereof. Both the guide block 11 and the substrate 12 can use standard optical components existing at present. In the following description, the fiber 15 is described as being fixed to the guide block 11, but the fiber 15 may be fixed to either the guide block 11 or the substrate 12. The fiber 15 may be any medium that can transmit light, and may be a ribbon fiber or the like.

  The substrate 12 has a terrace structure having a stepped portion. A light emitting / receiving element is placed on the lower side 34 of the stepped portion (substrate or support). The height of the step portion of the substrate 12 is adjusted to a predetermined height in response to the height position of the fiber 15 placed on the high side 35 of the step portion. In general, the fiber 15 provided on the high side 35 of the stepped portion and the light emitting / receiving element 36 (VICSEL) disposed on the surface of the substrate 12 are adjusted to have substantially the same height. By adopting such a simple structure for adjusting the height between the fiber 15 and the light emitting / receiving element 36, the height of the step portion and the state of optical transmission between the fiber 15 and the light emitting / receiving element 36 are adjusted. The height adjustment of the light emitting / receiving element 36 and the fiber 15 can be performed freely and easily. Note that a plurality of light emitting / receiving elements 36 may be arranged in an array on the substrate 12 in a state where light can be received and emitted in the vertical direction, for example, in a state where light can be emitted upward.

  On the high side 35 of the stepped portion, a V-shaped substrate fiber groove 16 for placing the fiber 15 and a V-shaped substrate guide pin groove 17 for placing the guide pin 18 are respectively provided in the fiber 15. A plurality of them are juxtaposed along the extending direction. The number of these grooves and the pitch interval are not particularly limited. As an example, here, a total of four substrate fiber grooves 16 and a total of two substrate guide pin grooves 17 are provided, and the substrate fiber grooves 16 are sandwiched between the substrate guide pin grooves 17. As shown in FIG. 6, the trough line 29 of each substrate fiber groove 16 has a light receiving / emitting element on each extension line so that optical transmission can be satisfactorily performed between the fiber 15 and the light receiving / emitting element 36. It is preferable to correspond to each of the 36 light emitting points 37 on a one-to-one basis.

  It is preferable to use a substrate material having a thermal expansion coefficient close to that of the light emitting / receiving element 36. By selecting such a material, the resistance to temperature change can be improved. For example, since the light emitting / receiving element 36 is made of GaAs (thermal expansion coefficient 5.7 × E-6, longitudinal Young's modulus 86 Gpa), the substrate 12 is made of BK7 (thermal expansion coefficient 7.1 × E-6, longitudinal It is preferable to manufacture with a Young's modulus of 82 Gpa) or Si (thermal expansion coefficient 4.2 × E-6, longitudinal Young's modulus of 190 Gpa).

  When the optical module 1 is assembled, the guide block 11 sandwiches the fiber 15 and the guide pin 18 between its front bottom surface 31 and the entire top surface of the substrate 12. Further, the guide block 11 sandwiches the fiber 15 between its base end side bottom surface and the fiber support base 32. A V-shaped guide block fiber groove 30 and a guide pin groove 21 are respectively provided on the front bottom surface 31 of the guide block 11 at positions corresponding to the substrate fiber groove 16 and the substrate guide pin groove 17 of the substrate 12. The fiber 15 is stripped from the position between the fiber support base 32 and the guide block 11 in the vicinity of the exposed position 40, and the fiber strand 26 appears in the tip end side.

  As well shown in FIG. 5, when the guide block 11 and the substrate 12 are combined, the guide block fiber groove 30 of the guide block 11 and the substrate fiber groove 16 of the substrate 12, and the guide pin of the guide block 11 By the groove 21 and the substrate guide pin groove 17 of the substrate 12, rectangular holes 44 and 46 having a rhombus cross-sectional shape are formed, respectively.

  A fiber strand 26 is disposed in the rectangular hole 44. In order to prevent an optical signal error, it is preferable that the fiber strand 26 is provided by being completely fixed to the guide block fiber groove 30 side of the guide block 11 using an adhesive or the like, for example. The fiber strands 26 are preferably provided in a state of being completely embedded in, for example, a recess of the guide block fiber groove 30 of the guide block 11. In order to maintain the strength of the fiber strand 26 sufficiently, it is necessary to pour a large amount of adhesive. As a result, there is a high risk of the adhesive sticking out. There is a risk of damaging the strands 26. By making the fiber strand 26 completely embedded in the recess of the V-groove, such end face treatment can be eliminated, and the process can be simplified.

  In the rectangular hole 46, the guide pin 18 having an inner diameter extending over both the guide pin groove 21 and the substrate guide pin groove 17 is disposed. As the guide pin 18, a rod-shaped ready-made product such as a resin can be used. For example, the guide block 18 and the substrate 12 are sandwiched by sandwiching the guide pin 18 in the grooves 21 and 17 so that the upper and lower half of the guide pin 18 protrudes into the guide pin groove 21 and the substrate guide pin groove 17, respectively. Can be easily positioned. More specifically, when the guide block 11 and the substrate 12 are aligned using the guide pin 18, the guide pin 18 is sandwiched between the V-grooves of the guide pin groove 21 and the substrate guide pin groove 17. The trough lines of the guide block fiber groove 30 and the substrate fiber groove 16 automatically coincide with each other, and the axis of the fiber 15 (the trough line 29) and the light emitting point 37 of the light receiving and emitting element 36 are on the same line. The guide pin 18 need only be incorporated between the guide pin groove 21 and the substrate guide pin groove 17, and does not necessarily have to be attached with an adhesive like the fiber strand 26. Even when an adhesive is used, it is not necessary to attach the adhesive completely using a large amount of adhesive unlike the fiber strand 26.

  The size and shape of the rectangular holes 44 and 46 are varied depending on the depth and shape of the guide pin groove 21 and the guide block fiber groove 30 of the guide block 11 or the substrate guide pin groove 17 and the substrate fiber groove 16 of the substrate 12. be able to. For example, the apex angles of the guide pin groove 21, the guide block fiber groove 30, the substrate guide pin groove 17, and the substrate fiber groove 16 are all 60 degrees, the outer diameter of the guide pin 18 is 0.125 mm, and the outer diameter of the cladding of the fiber 15 is It may be 0.08 mm, the core diameter may be 0.05 mm, and the adhesive layer between the guide block 11 and the substrate 12 may be 0.01 mm. If all of the guide pin groove 21, the guide block fiber groove 30, the substrate guide pin groove 17, and the substrate fiber groove 16 have the same depth and shape, they can all be processed in the same process, and are vertically symmetrical. The present invention can be realized with the V-groove, and as a result, the mutual positional accuracy or dimensional accuracy can be increased. Further, when the guide pin groove 21, the guide block fiber groove 30, the substrate guide pin groove 17, and the substrate fiber groove 16 are all extended in the same direction, in the step of mounting the light emitting / receiving element, The surface and the guide can be fixed while observing from the same direction, and accurate alignment is possible even with an inexpensive apparatus.

  Although not shown in particular, it is assumed that the tip of the fiber 15 is slightly protruded from the end face of the fiber block oblique surface 19 during the manufacturing process. These protruding tips, together with the end face of the fiber block slant surface 19, are at an angle of about 45 degrees so that good light transmission can be performed with the light emitting / receiving element 36 positioned below the fiber 15. End face is cut. In addition, you may provide a reflecting film in the fiber block diagonal surface 19 as needed. As described above, since the 45 degree plane of the guide block 11 is processed together with the fiber 15 after fixing the fiber 15, the processing cost can be suppressed even if the number of cores of the fiber 15 (fiber strand 26) increases. . Further, since end face processing is performed after all the fibers 15 are fixed, it is possible to make a part in which the 45-degree faces of all the fibers 15 are almost exactly coincident.

  As is clear from the above description, the guide block 11 having a 45-degree surface abuts against the substrate 12 using the guide pin 18 to determine the position in the plane direction perpendicular to the guide pin 18. Thus, it can be easily positioned with respect to the light emitting / receiving element 36. The guide block 11 can be easily adjusted in position in the axial direction of the guide pin 18 by moving the guide pin 18 along the guide pin groove 21 on the guide block 11 side, for example. The method may be an active alignment process in which the light emitting / receiving element 36 is driven to input / output light from one end of the guide block 11 and monitor its output even in a process based on image recognition.

  Next, an operation example of the optical module 1 will be described with reference to FIG. Both the light beam 42 emitted from the light receiving / emitting element 36 and incident on the fiber strand 26, or the light beam 42 emitted from the fiber strand 26 and incident on the light receiving / emitting element 36 are both 45-degree planes 48 of the fiber strand 26. Is converted by 90 degrees to change the optical path. Furthermore, the end surface 48 of the fiber strand 26 is processed at 45 degrees like the fiber block oblique surface 19. For example, light from the substrate 12 side is reflected by the surface 48 through the cladding 28, and the core The light is guided into 27. In this regard, the distance between the light emitting surface and the fiber core may be made closer by using the fiber 15 having a thin cladding system. The optical path conversion can be adjusted easily and accurately by adjusting the height of the support base 13, for example. In this way, the light emitting / receiving element 36 and the 45 degree surface 48 of the fiber strand 26 can always be brought close to each other in an optimum state. With such a configuration, the optical module 1 can perform high-efficiency optical coupling without using a condensing component such as a lens. Further, with such a configuration, the optical coupling efficiency can be increased. If appropriate, the refractive index of light is adjusted by interposing a refractive member between the fiber strand 26 and the light emitting / receiving element 36, and the light from the light emitting / receiving element 36 or the light receiving / emitting element 36 is adjusted. May be transmitted in a more effective manner inside the fiber strand 26.

  12 to 14 show an optical module 1A according to a second embodiment of the present invention. 12 to 14 correspond to FIGS. 2, 4, and 5 of the first embodiment, respectively. Similar members are denoted with similar reference numbers or with alphabetical characters after similar reference numbers. The second embodiment is an example in which the fiber strand 26 of the first embodiment is also used as a guide pin. Here, the fiber strand 26 is in a state of protruding approximately half in the guide block fiber groove 30A of the guide block 11 and the substrate fiber groove 16A of the substrate 12, and is fixed to the guide block fiber groove 30A of the guide block 11, for example. ing. The end face is 45 degrees, etc., as in the first embodiment. Since the fiber strand 26 itself is a guide pin, the positions of the fiber strand 26 of the guide block 11 and the substrate fiber groove 16A of the substrate 12 are more accurately aligned than in the first embodiment. As a result, the positional accuracy with respect to the light emitting / receiving element 36 aligned with the V groove is also increased.

  FIG. 15 shows an optical module 1B according to a third embodiment of the present invention. This figure corresponds to FIG. 1 of the first embodiment. In this embodiment, the width of the substrate 12 and the light emitting / receiving element 36 is wide enough to provide a plurality of groups of the light emitting / receiving elements 36, and the substrate fiber groove 16 and the substrate guide pin groove 17 according to the individual elements. The guide pin groove 21 and the guide block fiber groove 30 are provided. Thereby, a composite module can be realized without impairing the characteristics of the optical module of the first embodiment. For example, in the example shown in FIG. 15, two groups of light emitting / receiving elements 36, and three guide pins (not shown) and three guide pin grooves 21 are provided. The group of light receiving and emitting elements 36, that is, the light receiving and emitting elements 36a on 34b and the light receiving and emitting elements 36b on 34b may be the same element. For example, 36a may be a light emitting component and 36b may be a light receiving component. Further, the oscillation wavelength of the 34b light emitting / receiving element 36a may be different from the oscillation wavelength of the 34b light receiving / emitting element 36b.

  FIG. 16 shows an optical module 1C according to a fourth embodiment of the present invention. This figure corresponds to FIG. 1 of the first embodiment. In this embodiment, the fiber 15 protruding from the optical module 1 is accommodated in the first and second connector parts 50 and 52 integrated with the fiber support base 32. The fiber 15 passes through the 50 through holes 51 and is then accommodated in the fiber accommodating portion 53 of the second connector component 52. By providing the first and second connector parts 50 and 52, the fiber 15 and the fiber strand 26 can be prevented from being exposed to the outside.

  17 and 18 show an optical module 1D according to a fifth embodiment of the present invention. 17 and 18 correspond to FIGS. 1 and 6 of the first embodiment, respectively. In the fifth embodiment, wirings 38 for electrical connection with the light emitting / receiving elements 36 are provided on the lower side 34D of the stepped portion of the substrate 12. Through this wiring 38, a signal from the fiber 15 can be exchanged with the outside of the optical module 1D.

1 is a perspective view of an optical module according to a first embodiment of the present invention. It is a top view of the optical module of FIG. It is a side view of the optical module of FIG. It is a front view of the optical module of FIG. FIG. 5 is a partial enlarged view of FIG. 4. It is a top view of the V-groove board | substrate of the optical module of FIG. It is a side view of the V-groove board | substrate of FIG. It is a bottom view of the guide block of the optical module of FIG. It is a side view of the guide block of FIG. FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. 4. It is a partial partial enlarged view of FIG. It is a top view of the optical module by the 2nd example of the present invention. It is a front view of the optical module of FIG. FIG. 14 is a partial enlarged view of FIG. 13. It is a perspective view of the optical module by the 3rd example of the present invention. It is a perspective view of the optical module by the 4th example of the present invention. It is a perspective view of the optical module by the 5th example of the present invention. It is a perspective view of the V-groove board | substrate of the optical module of FIG. It is a figure which shows an example of the end surface type light emitting / receiving element used for the conventional optical module.

Explanation of symbols

11 Guide block 12 V-groove substrate 15 Fiber 16 Substrate fiber groove 17 Substrate guide pin groove 18 Guide pin 19 Fiber block oblique surface 21 Guide pin groove (V groove)
26 Fiber strand 27 Core 28 Clad 29 Valley wire 30 Guide block fiber groove (V groove)
31 Front side bottom surface 32 Fiber support base 34 Step part (low side)
35 Stepped part (high side)
36 Light emitting / receiving element 37 Light emitting point 38 Wiring 40 Exposed position 42 Light beam 44 Fiber rectangular hole 46 Guide pin rectangular hole 48 45 degree surface 50 First connector part 51 Through hole 52 Second connector part 53 Fiber receiving portion

Claims (7)

An optical module equipped with a surface emitting / emitting element,
A support with a step,
A block member for fixing the optical transmission medium disposed on the side higher than the support base in a state of being completely embedded in the recess of the groove ;
The surface light emitting / receiving element disposed on the lower side of the support base in a state capable of receiving and emitting light in the vertical direction at a position corresponding to the end surface of the optical transmission medium disposed on the higher side than the support base. Have
Optical transmission is performed between the optical transmission medium and the surface-receiving / emitting element,
The higher side of the support base has a groove along the extending direction of the optical transmission medium,
The block member has a groove extending to a side closer to the surface light emitting and emitting element than the groove at a position corresponding to the groove provided on the high side of the support base,
A guide member having an inner diameter that spans both the groove provided on the support base and the groove provided on the block member is sandwiched between the grooves to position the support base and the block member relative to each other. ,
There are a plurality of grooves provided in the block member, and they are all the same depth or shape,
The optical transmission medium is extended in a recess of a groove provided in the block member to a side closer to the surface light emitting / emitting element than a groove provided on a higher side of the support base. It is provided in a state where the side is exposed and is fixed and completely embedded therein ,
The optical module , wherein the block member has an end surface processed together with the optical transmission medium in a vicinity of a position where the optical transmission medium and the surface light emitting / receiving element perform optical transmission .   The optical module according to claim 1, wherein the end surface processing is performed to have an angle of about 45 degrees.   The optical module according to claim 1, wherein there are a plurality of grooves provided in the support base, and all of them have the same depth or shape.   4. The optical module according to claim 1, wherein the groove provided on the support base and the groove provided on the block member all have the same depth or shape.   5. The optical module according to claim 1, wherein a thermal expansion coefficient of a material of the support base is substantially the same as that of the light receiving and emitting element.   A plurality of the light emitting / receiving elements are arranged on the support base, some of the light receiving / emitting elements are light receiving parts, and some of the light receiving / emitting elements are light emitting parts, or The optical module according to claim 1, wherein some oscillation wavelengths of the light receiving and emitting elements are different from some other oscillation wavelengths of the light receiving and emitting elements. The optical module according to claim 1, wherein the optical transmission medium is accommodated in a connector integrated with a fiber support .

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