Optical waveguide component

Abstract

To provide an optical waveguide component capable of obtaining high coupling efficiency between an optical waveguide and an optical fiber.SOLUTION: An optical waveguide component comprises: a base board having a first main surface; an optical waveguide provided on the first main surface and including first cores; and a first optical connector fixed on the base board and including first collimator lenses. First distances between first principal points of the first collimator lenses and first end faces of the first cores are equal to first focal lengths of the first collimator lenses.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to optical waveguide components. [Background technology]

[0002] Various techniques have been proposed for optically coupling an optical fiber to an optical waveguide provided on a substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-081299 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-114645 [Non-patent literature]

[0004] [Non-Patent Document 1] A. Noriki et al., “Low-Cost MT-Ferrule-Compatible Optical Connector for Co-packaged Optics Using Single-Mode Polymer Waveguide,” Electronic Components and Technology Conference, 1 May 2019 Summary of the Invention [Problem to be solved by the invention]

[0005] With conventional techniques, it is difficult to achieve high coupling efficiency between an optical waveguide and an optical fiber.

[0006] An object of the present disclosure is to provide an optical waveguide component that can achieve high coupling efficiency between an optical waveguide and an optical fiber. [Means for solving the problem]

[0007] According to one embodiment of the present disclosure, there is provided an optical waveguide component comprising: a substrate having a first main surface; an optical waveguide provided on the first main surface and including a first core; and a first optical connector fixed to the substrate and including a first collimating lens, wherein a first distance between a first principal point of the first collimating lens and a first end face of the first core is equal to a first focal length of the first collimating lens. [Effects of the Invention]

[0008] According to the present disclosure, high coupling efficiency can be obtained between an optical waveguide and an optical fiber. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view illustrating an optical waveguide component according to an embodiment; [Figure 2] 1 is a cross-sectional view (part 1) illustrating an optical waveguide component according to an embodiment. [Figure 3] FIG. 2 is a cross-sectional view (part 2) illustrating the optical waveguide component according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description may be omitted.

[0011] [Structure of optical waveguide components] The structure of an optical waveguide component according to an embodiment will be described. Fig. 1 is a plan view illustrating an optical waveguide component according to an embodiment. Figs. 2 and 3 are cross-sectional views illustrating an optical waveguide component according to an embodiment. Fig. 2 corresponds to a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 shows an enlarged view of a portion of Fig. 2.

[0012] As shown in FIGS. 1 to 3, an optical waveguide component 1 according to the embodiment includes an optical waveguide substrate 30, a first optical connector 10, a second optical connector 20, and an optical semiconductor chip 50. The first optical connector 10 is a first optical connector, a second optical connector 20, and an optical semiconductor chip 50. As shown in FIG.

[0013] The optical waveguide substrate 30 includes a substrate 31 and an optical waveguide 32 .

[0014] The substrate 31 is, for example, a wiring substrate, and has a wiring pattern (not shown) and electrodes (not shown). The optical waveguide 32 is provided on one main surface 31A of the substrate 31. The main surface 31A is an example of a first main surface.

[0015] In this embodiment, for convenience, the optical waveguide 32 side is referred to as the upper side or one side, and the opposite side is referred to as the lower side or other side, with the substrate 31 as the reference. The upper surface of each part is referred to as the one side or top surface, and the lower surface is referred to as the other side or bottom surface. However, the optical waveguide component 1 can be used upside down or positioned at any angle. Furthermore, a planar view refers to viewing an object from the normal direction of the main surface 31A of the substrate 31, and a planar shape refers to the shape of the object viewed from the normal direction of the main surface 31A of the substrate 31.

[0016] The optical waveguide 32 has a first cladding layer 33, a plurality of core layers 34, and a second cladding layer 35. The optical waveguide 32 is a polymer waveguide. The core layers 34 are an example of a first core.

[0017] The first cladding layer 33 is provided on the substrate 31. The material of the first cladding layer 33 is, for example, an organic resin such as an epoxy resin or a polyimide resin. The thickness of the first cladding layer 33 is, for example, about 10 μm to 30 μm.

[0018] The core layers 34 are provided in a strip shape on the first cladding layer 33. The material of the core layers 34 is, for example, an organic resin such as an epoxy resin or a polyimide resin. For example, the cross section of the core layers 34 perpendicular to the extension direction is rectangular. To obtain a single-mode optical waveguide, the core layers 34 may have a very small cross-sectional area. For example, the width of the core layers 34 is 5 μm to 10 μm, and the height is 5 μm to 10 μm.

[0019] The second cladding layer 35 is provided on the first cladding layer 33 and the plurality of core layers 34. The second cladding layer 35 covers the plurality of core layers 34. The material of the second cladding layer 35 is, for example, an organic resin such as an epoxy resin or a polyimide resin. The thickness of the second cladding layer 35 is, for example, about 10 μm to 30 μm. A portion of the core layer 34 may be exposed from the second cladding layer 35 on both sides of the core layer 34 in the extension direction.

[0020] In the optical waveguide 32, the refractive index of the core layer 34 is higher than the refractive indexes of the first cladding layer 33 and the second cladding layer 35.

[0021] The optical semiconductor chip 50 includes an optical element (not shown) and is mounted on the substrate 31. The optical semiconductor chip 50 has a plurality of electrodes 51 and is flip-chip mounted on the substrate 31. The optical semiconductor chip 50 is disposed on one side of the core layer 34 in the extension direction, and the optical element is optically coupled to the optical waveguide 32. The optical element may be either a light-receiving element or a light-emitting element.

[0022] The optical waveguide substrate 30 has an end face 30A on the side opposite to the optical semiconductor chip 50 in the extension direction of the core layers 34. The end face 30A includes each first end face 34A of the multiple core layers 34. For example, the first end face 34A is perpendicular to the optical axis of the core layer 34.

[0023] The first optical connector 10 has a first glass member 11 and a plurality of first collimating lenses 12. For example, the first glass member 11 and the plurality of first collimating lenses 12 are integrally formed from glass. The first optical connector 10 has a first surface 10A that is in close contact with a first end surface 34A of the core layer 34. The first end surface 34A and the first surface 10A may be bonded to each other with an optically transparent adhesive.

[0024] A recess 10S recessed toward the first surface 10A is formed on the surface 10B of the first optical connector 10 opposite the first surface 10A, and multiple first collimating lenses 12 are provided on the bottom 10T of the recess 10S. The number of first collimating lenses 12 is equal to the number of core layers 34. The first collimating lenses 12 are located on the optical axes of the core layers 34, and one first collimating lens 12 and one core layer 34 form a pair. In each pair, a first distance L1 between a first principal point 12P of the first collimating lens 12 and a first end surface 34A of the core layer 34 is equal to the first focal length of the first collimating lens 12. A portion of the first glass member 11 is located between the first collimating lens 12 and the first surface 10A. The diameter of the first collimating lens 12 is, for example, approximately 100 μm.

[0025] The optical waveguide 32 has one surface 32A and the other surface 32B that are continuous with the end surface 30A. The surface 32A contacts the main surface 31A of the substrate 31, and the surface 32B is on the opposite side to the surface 32A. The surfaces 32A and 32B are parallel to the main surface 31A. For example, the core layer 34 is exposed on the surface 32B. Furthermore, a second clad layer 35 may be provided between adjacent core layers 34, and this portion of the second clad layer 35 may also be exposed on the surface 32B.

[0026] The first optical connector 10 has a second surface 10C that is continuous with the first surface 10A and is in close contact with the surface 32B of the optical waveguide 32. For example, the angle between the first surface 10A and the second surface 10C is 90 degrees. The surface 32B and the second surface 10C may be bonded to each other with a light-transmitting adhesive.

[0027] The first optical connector 10 has an alignment mark 18. The alignment mark 18 may be formed mechanically, such as a recess, or may be formed by a coloring process such as ion implantation.

[0028] The second optical connector 20 has a second glass member 21, a plurality of second collimating lenses 22, and a plurality of optical fiber cores 26. For example, the second glass member 21 and the plurality of second collimating lenses 22 are integrally formed from glass. The number of second collimating lenses 22 and the number of cores 26 are equal to the number of core layers 34 and the number of first collimating lenses 12. The second glass member 21 can function as a cladding for the cores 26. The cores 26 are an example of second cores.

[0029] The second optical connector 20 has a surface 20A and a surface 20B opposite to surface 20A. The optical axes of the cores 26 are parallel to each other within the second glass member 21. For example, surfaces 20A and 20B are perpendicular to the optical axes of the cores 26 within the second glass member 21. The cores 26 extend outward from surface 20A.

[0030] A recess 20S recessed toward the surface 20A is formed on the surface 20B, and a plurality of second collimating lenses 22 are provided on the bottom 20T of the recess 20S. The second collimating lenses 22 are located on the optical axes of the cores 26, and one second collimating lens 22 and one core 26 form a pair. In each pair, a second distance L2 between a second principal point 22P of the second collimating lens 22 and a second end face 26A of the core 26 is equal to the second focal length of the second collimating lens 22. A portion of the second glass member 21 is located between the second collimating lens 22 and the second end face 26A. The diameter of the second collimating lens 22 is, for example, approximately 100 μm.

[0031] The second optical connector 20 is detachably attached to the first optical connector 10. When the second optical connector 20 is coupled to the first optical connector 10, the surface 10B of the first optical connector 10 and the surface 20B of the second optical connector 20 face each other, and the recesses 10S and 20S are connected to each other. The optical waveguide component 1 also has a restraining mechanism 40. The restraining mechanism 40 has a plurality of fitting holes 41 provided on the surface 10B and a plurality of fitting pins 42 provided on the surface 20B, each fitting into the fitting holes 41. For example, the fitting holes 41 are located on both outer sides of the recess 10S in the direction in which the plurality of first collimating lenses 12 are arranged, and the fitting pins 42 are located on both outer sides of the recess 20S in the direction in which the plurality of second collimating lenses 22 are arranged. By fitting the mating pins 42 into the mating holes 41, the first optical connector 10 and the second optical connector 20 are mechanically restrained from misalignment in a direction parallel to the faces 10B and 20B of the connectors. The first collimating lenses 12 and the second collimating lenses 22 face each other, and a signal of collimated light 45 is transmitted between the facing first collimating lenses 12 and second collimating lenses 22. In this way, the restraining mechanism 40 restrains the first optical connector 10 and the second optical connector 20 from each other in a direction perpendicular to the optical axis of the collimated light 45. Preferably, the mode field diameter (MFD) is the same between the core layer 34 and the core 26.

[0032] The positions of the fitting holes 41 and the fitting pins 42 are not limited. The fitting holes 41 may be located on both sides of the row of first collimating lenses 12 in the extension direction of the core layer 34, and the fitting pins 42 may be located on both sides of the row of second collimating lenses 22 in the extension direction of the core 26.

[0033] [Methods of manufacturing and using optical waveguide components] Next, a method for manufacturing and using the optical waveguide component according to the embodiment will be described.

[0034] First, the optical waveguide substrate 30 is prepared, and the optical semiconductor chip 50 is mounted on the substrate 31. Next, the first optical connector 10 is attached to the optical waveguide substrate 30. At this time, alignment marks 18 are provided at positions that overlap specific core layers 34 in a plan view of the first optical connector 10. By aligning the alignment marks 18 with the core layers 34 visible through the first glass member 11, alignment in the direction in which the core layers 34 are aligned can be easily achieved. Furthermore, by closely adhering the first surface 10A to the end surface 30A of the optical waveguide substrate 30, alignment in the extension direction of the core layers 34 can be easily achieved. Furthermore, by closely adhering the second surface 10C to the surface 32B of the optical waveguide 32, alignment in the thickness direction of the optical waveguide substrate 30 can be easily achieved. The first optical connector 10 may be fixed to the optical waveguide substrate 30 using, for example, a light-transmitting adhesive.

[0035] The optical waveguide component 1 is used by connecting the first optical connector 10 and the second optical connector 20 to each other. When connecting, the second optical connector 20 is pressed against the first optical connector 10 while the mating pins 42 are fitted into the mating holes 41. Then, the second optical connector 20 is fixed to the first optical connector 10. The second optical connector 20 can be detachably fixed to the first optical connector 10 using, for example, a latch mechanism or the like.

[0036] In this manner, the optical waveguide component 1 according to the embodiment can be manufactured and used.

[0037] In the optical waveguide component 1, collimated light 45 transmitted through the first collimating lens 12 and the second collimating lens 22 is used for transmitting light between the core layer 34 and the core 26. This reduces loss and improves coupling efficiency.

[0038] For example, there may be a slight margin between the fitting hole 41 and the fitting pin 42, the second principal point 22P of the second collimating lens 22 may be slightly offset from the optical axis of the core layer 34, and the first principal point 12P of the first collimating lens 12 may be slightly offset from the optical axis of the core 26. Even with such offsets, by using collimated light 45, the light emitted from the first collimating lens 12 is focused on the second end face 26A of the core 26, and the light emitted from the second collimating lens 22 is focused on the first end face 34A of the core layer 34. In this way, the core layer 34 and the core 26 can be optically coupled by passive alignment.

[0039] The second optical connector 20 may be composed of a plurality of components. For example, the second optical connector 20 may be configured by bonding a component in which the second end face 26A of the core 26 is exposed and a component including the second collimating lens 22 together.

[0040] Although the preferred embodiments have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims. [Explanation of symbols]

[0041] 1. Optical waveguide components 10 First optical connector 11 First glass member 12 First collimating lens 12P 1st main point 18 Alignment Mark 20 Second optical connector 21 Second glass member 22 Second collimating lens 22P 2nd principal point 26 cores 30 Optical waveguide substrate 31 PCB 32 Optical waveguide 33 First cladding layer 34 Core layer 35 Second cladding layer 40 Restraint mechanism 41 Fitting hole 42 mating pins 45 Collimated Light

Claims

1. a substrate having a first major surface; an optical waveguide provided on the first main surface and including a first core; a first optical connector fixed to the substrate and including a first collimating lens; and an optical waveguide component, wherein a first distance between a first principal point of the first collimating lens and a first end face of the first core is equal to a first focal length of the first collimating lens;

2. The optical waveguide component according to claim 1 , wherein the first optical connector has a first surface that comes into close contact with the first end surface.

3. 3. The optical waveguide component according to claim 2, wherein the first optical connector has a first glass member located at least between the first collimating lens and the first surface.

4. 3. The optical waveguide component according to claim 1, wherein the optical waveguide is a polymer waveguide.

5. a second optical connector including a second collimating lens and detachable from the first optical connector; 3. The optical waveguide component according to claim 1, wherein a collimated light signal is transmitted between the first collimating lens and the second collimating lens.

6. the second optical connector includes a second core of an optical fiber; 6. The optical waveguide component according to claim 5, wherein a second distance between a second principal point of the second collimating lens and a second end face of the second core is equal to a second focal length of the second collimating lens.

7. 7. The optical waveguide component according to claim 6, wherein the second optical connector has a second glass member located at least between the second collimating lens and the second end face.

8. 6. The optical waveguide component according to claim 5, further comprising a restraining mechanism that restrains the first optical connector and the second optical connector relative to each other in a direction perpendicular to the optical axis of the collimated light.

9. 3. The optical waveguide component according to claim 1, further comprising an optical semiconductor chip mounted on the substrate and optically coupled to the optical waveguide.

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