Optical module

Abstract

The present invention relates to an optical module comprising: an optical waveguide (10) which has a core (11) and a sheet-like cladding (12) including a plurality of cores arranged side by side in the width direction, and which has different widths at both ends in the longitudinal direction as a result of being deformed in the width direction along the longitudinal direction; and a substrate (30) to which one longitudinal-end side of the optical waveguide is connected, wherein the one longitudinal-end sides of a plurality of such optical waveguides (10) are connected in the same plane of the substrate (30).

Description

Optical module

[0001] The present invention relates to an optical module.

[0002] Silicon photonics, which is a technology for integrating silicon optical circuits on a silicon chip, has attracted attention. In silicon photonics, for example, as shown in Patent Document 1, an optical waveguide is known as a waveguide for transmitting an optical signal between a silicon optical waveguide formed in an optical integrated circuit and an optical fiber. According to such an optical waveguide, cores can be arranged at a higher density compared to an optical fiber.

[0003] Patent Document 2 discloses a configuration of an optical connector and an optical transmission module having a first lens that reflects light emitted from a first optical transmission path, a second lens that reflects light emitted from a second optical transmission path, a third lens that collimates the light reflected by the first lens, and a fourth lens that collimates the light reflected by the second lens, as a configuration for transmitting the light transmitted from an optical fiber to the substrate side at a high density.

[0004] Japanese Patent Application Laid-Open No. 2014-81586, Japanese Patent Application Laid-Open No. 2017-134282

[0005] In Patent Document 2, the purpose is to increase the mounting density of optical fibers connected to an optical integrated circuit by reflecting the light irradiated from a plurality of optical fibers arranged two-dimensionally in two rows in the vertical direction toward the same plane of the substrate. However, it is necessary to attach the optical fibers to the optical connector with high precision, and a lens corresponding to each optical fiber is required, resulting in an increase in the number of parts. Therefore, there are problems in terms of workability and cost during assembly. Furthermore, as a means for transmitting an optical signal to a silicon optical waveguide provided on the substrate side of the optical integrated circuit, only vertical coupling or grating coupling can be used, so there is also a problem with versatility.

[0006] The present invention has been made in view of the above situation, and its object is to provide an optical module that can mount cores for transmitting light to the substrate of an optical integrated circuit at a high density with a simple and low-cost configuration, and can connect the cores to a silicon optical waveguide provided in the optical integrated circuit with high space efficiency.

[0007] The above object of the present invention is achieved by the following configuration: (1) an optical module having a core and a sheet-like cladding including a plurality of the cores arranged side by side in the width direction, wherein the optical waveguide is deformed in the width direction along the longitudinal direction so that the widths of the two ends in the longitudinal direction are different, and a substrate to which one end in the longitudinal direction of the optical waveguide is connected, wherein one end in the longitudinal direction of the plurality of optical waveguides is connected within the same plane of the substrate.

[0008] According to the present invention, by connecting optical waveguides with different widths at both ends in the longitudinal direction within the same plane of a substrate, a core that transmits light to the substrate can be densely arranged in a simple and low-cost configuration. Furthermore, the core of the optical waveguide can be connected to the substrate side in a space-efficient manner.

[0009] Figure 1 is a perspective view showing one embodiment of an optical module to which the present invention is applied. Figure 2 is a plan view showing one embodiment of an optical module to which the present invention is applied. Figure 3 is a side view showing one embodiment of an optical module to which the present invention is applied. Figure 4 is a model diagram showing the cross-sectional shape of a polymer optical waveguide. Figure 5 is an exploded perspective view showing the connection configuration between the polymer optical waveguide and the optical circuit board. Figure 6 is a side view showing an optical module of the second embodiment. Figure 7 is a plan view showing an optical module of the third embodiment. Figure 8 is a perspective view showing an optical module of the fourth embodiment. Figure 9 is a plan view showing an optical module of the fourth embodiment. Figure 10 is a perspective view showing an optical module of the fifth embodiment.

[0010] <First Embodiment> Hereinafter, preferred embodiments of the optical module of the present invention shown in the attached drawings will be described. Figure 1 is a perspective view showing one embodiment of an optical module to which the present invention is applied. Figure 2 is a plan view showing one embodiment of an optical module to which the present invention is applied. Figure 3 is a side view showing one embodiment of an optical module to which the present invention is applied. Figure 4 is a model diagram showing the cross-sectional shape of a polymer optical waveguide. Figure 5 is an exploded perspective view showing the connection configuration between the polymer optical waveguide and the optical circuit board.

[0011] The optical module 100 shown in Figure 1 comprises a pair of upper and lower polymer optical waveguides 10, a connector 20 that supports one end of the polymer optical waveguide 10, and an optical circuit board 30 of an optical integrated circuit to which the other end of the polymer optical waveguide 10 is connected.

[0012] (Polymer Optical Waveguide 10) As shown in Figure 1, the polymer optical waveguide 10 comprises a core 11 that transmits light and a sheet-like cladding 12 that encloses the core 11. Due to the widthwise outer edge shape of the cladding 12, it is a sheet-like optical waveguide with different widths at both ends in the longitudinal direction. Furthermore, as shown in Figures 1 and 2, the polymer optical waveguide 10 has a connector-side end 10a connected to the connector side, a substrate-side end 10b that is narrower than the connector-side end 10a and connected to the optical circuit board 30 side, and a deformed portion 10c in which the widthwise outer edge shape is deformed so as to narrow from the connector-side end 10a to the substrate-side end 10b. In this embodiment, the deformed portion 10c is a portion in which one side of the cladding 12 in the widthwise direction is curved in an S-shape from the connector-side end 10a to the substrate-side end 10b. The other end of the cladding 12 in the widthwise direction is formed straight along the longitudinal direction. The shape of the deformed portion 10c is not limited to the shape shown in the figure, and may be formed at both ends in the width direction of the cladding 12.

[0013] In the polymer optical waveguide 10, multiple cores 11 are arranged in parallel along the direction of light propagation of the cores 11 in the polymer optical waveguide 10 (hereinafter referred to in this specification as "direction of light propagation in the polymer optical waveguide" or "longitudinal direction of the polymer optical waveguide"). As shown in Figure 1, the multiple cores 11 arranged side by side within the cladding 12 are curved along the outer edge shape of the polymer optical waveguide 10. As a result, at the substrate-side end 10b of the polymer optical waveguide 10, the space between the cores 11 arranged side by side in the width direction becomes narrower, and the cores 11 are arranged at a high density.

[0014] As shown in Figures 1 to 3, two polymer optical waveguides 10 are arranged vertically between the connector 20 and the optical circuit board 30. As shown in Figures 1 and 2, the upper and lower polymer optical waveguides 10 are arranged so that a portion of them near the connector-side end 10a overlaps in a plan view, and the deformed portion 10c extends in different directions in the width direction so that the substrate-side end 10b does not overlap in a plan view. As shown in Figure 3, the lower polymer optical waveguide 10 is arranged without vertical displacement from the connector 20 toward the optical circuit board 30, while the upper polymer optical waveguide 10 is curved downward in the middle of its longitudinal direction toward the connector 20 toward the optical circuit board 30.

[0015] As a result, the upper and lower polymer optical waveguides 10 are arranged so that at least a portion of them overlap in a plan view, with the connector-side ends 10a attached to the connector 20. Meanwhile, the substrate-side ends 10b of the upper and lower polymer optical waveguides 10 are connected to substrate-side coupling portions 31 that are formed side by side in the width direction on the same plane of the optical circuit board 30.

[0016] Furthermore, there may be two or more polymer optical waveguides 10 arranged between the connector 20 and the optical circuit board 30, and are not limited to two. Also, the multiple polymer optical waveguides 10 only need to have their substrate-side ends 10b connected on the same plane as the optical circuit board 30, and two or more polymer optical waveguides 10 may be displaced in the vertical direction, or not all of the polymer optical waveguides 10 may be displaced in the vertical direction.

[0017] As shown in Figure 4, the cladding 12 of the polymer optical waveguide 10 comprises an undercladding 13 and an overcladding 14. The undercladding 13 has a lower refractive index than the core 11 and is located around the core 11. The overcladding 14 has a lower refractive index than the core 11 and is located around the core 11 on the opposite side from the undercladding 13.

[0018] In the polymer optical waveguide 10 of this embodiment, the periphery (outside in the width direction and one side in the vertical direction) of a plurality of cores 11 arranged in a line in the width direction on the plane of a sheet-like underclad 13 is covered by a sheet-like overclad 14. Note that the cores 11 contained within the clad 12 may be configured such that a portion of the longitudinal end of the core 11 is not covered by the overclad 14 and is exposed.

[0019] As a result, multiple cores 11 are arranged side by side in the width direction within the overclad 14. In the illustrated example, twelve cores 11 are arranged side by side within the clad 12. Note that the number of cores 11 and the shape of the clad 12 are not limited to the illustrated shape. The distance between adjacent cores 11 within the overclad 14 is made larger than the mode field diameter, which is determined by the size of the core 11 and the difference in refractive index between the core 11 and the clad 12. This allows for a high density arrangement of cores 11 within the clad 12 while suppressing crosstalk caused by the mixing of light propagating between adjacent cores 11. The distance between adjacent cores 11 at the connector-side end 10a is set to 125 μm or 250 μm. The distance between adjacent cores 11 at the substrate-side end 10b is set between 10 μm and 100 μm. Note that the distances between any of the cores 11 are not limited to the above settings.

[0020] Furthermore, the film thickness, which is the vertical height of the underclad 13 and overclad 14, was made greater than half the mode field diameter. This prevents light from leaking out of the underclad 13 and overclad 14, which would increase the propagation loss of the core 11. The mode field diameter was set to 1 μm or more. The core height h of the core 11 was set to 0.1 μm or more and 50 μm or less, with a more preferable core height h being 0.5 μm or more and 30 μm or less. The core width of the core 11 was set to 0.5 μm or more and 50 μm or less, with a more preferable core width being 1 μm or more and 30 μm or less. With this configuration, the yield of the manufactured polymer optical waveguide is increased, as is the mounting density of the core 11. In this specification, "core width" refers to the width of the core in the direction perpendicular to the thickness direction of the polymer optical waveguide in a cross section perpendicular to the direction of light propagation in the polymer optical waveguide. "Core height" refers to the height of the core in the thickness direction of the polymer optical waveguide in a cross-section perpendicular to the direction of light propagation.

[0021] (Connector 20) The connector 20 is attached with the connector-side ends 10a of the two polymer optical waveguides 10 aligned vertically. Each connector 20 also has a pair of guide holes 28 for positioning the connector 20.

[0022] (Optical Circuit Board 30) The optical circuit board 30 is a substrate constituting an optical integrated circuit and has a substrate-side coupling portion 31 to which the substrate-side end 10b of the polymer optical waveguide 10 is connected. The optical circuit board 30 only needs to be such that the polymer optical waveguides 10 can be connected on the same plane. The optical circuit board 30 is a substrate on which general modules constituting an optical integrated circuit, such as receivers and transmitters, can be mounted, and its application is not limited. Multiple substrate-side coupling portions 31 are provided in accordance with the number of polymer optical waveguides 10 connected to the optical circuit board 30. Multiple substrate-side coupling portions 31 are arranged side by side on one side forming the outer edge of the optical circuit board 30. In this embodiment, as shown in Figures 1 and 2, two substrate-side coupling portions 31 are arranged side by side on one side of the optical circuit board 30 so that two polymer optical waveguides 10 are connected.

[0023] As shown in Figure 5, the substrate-side connecting portion 31 is linearly recessed from the end of the optical circuit board 30 and has multiple guide grooves 32 arranged in a row in the width direction, and a substrate-side connecting portion 33 which is a flat surface formed between adjacent guide grooves 32 in the width direction.

[0024] In the example shown in Figure 5, the guide groove 32 has a pair of inclined surfaces and a bottom, and is formed in a trapezoidal shape with a tapered angle that decreases in width as the groove deepens. The shape of the guide groove 32 is not limited to this, and may be rectangular, semicircular, or a V-groove that is a standard design for optical fiber mounting.

[0025] As a result, the guide groove 32 engages with a projection 15 formed by the substrate-side end 10b of the overcladding 14 constituting the polymer optical waveguide 10, as shown in Figure 5. With this configuration, by engaging the projection 15 of the polymer optical waveguide 10 with a predetermined position in the guide groove 32 of the optical circuit board 30, the polymer optical waveguide 10 can be smoothly and accurately positioned at the substrate-side coupling portion 31, which is a predetermined coupling position on the optical circuit board 30. Furthermore, with this configuration, lattice coupling, evanescent coupling, or direct coupling can be used as the optical connection method between the core 11 of the polymer optical waveguide 10 and the silicon optical waveguide on the optical circuit board 30 side.

[0026] The substrate-side coupling portion 31 is not limited to the illustrated configuration, as long as it can be connected to the substrate-side end portion 10b of the polymer optical waveguide 10.

[0027] (Function and Effects) According to the optical module 100 with the above configuration, the substrate-side ends 10b of the two polymer optical waveguides 10 supported by the connector 20 are connected to substrate-side coupling portions 31 arranged side by side on the same plane of the optical circuit board 30. With this configuration, the multiple cores 11 contained in the two polymer optical waveguides 10, which are formed to be narrow toward the optical circuit board 30, can be concentrated toward the optical circuit board 30 by deformation associated with the deformation portion 10c and connected to the substrate-side coupling portions 31 formed on the same plane. As a result, the cores 11 of the polymer optical waveguides 10 connected to the optical circuit board 30 can be arranged at a higher density. In other words, it is possible to achieve both increased capacity of the cores 11 that can be connected to the optical circuit board 30 and miniaturization of the optical circuit board 30 to which the cores 11 are connected.

[0028] As shown in Figure 2, the sheet-shaped polymer optical waveguides 10, which are supported in a vertical arrangement by the connector 20, are connected to the optical circuit board 30 on the same plane by curving at least one of the polymer optical waveguides 10 so that it is displaced vertically. With this configuration, multiple polymer optical waveguides 10 connected to the same plane of the optical circuit board 30 can be arranged in a vertically overlapping state, so that multiple polymer optical waveguides 10 can be installed more space-efficiently.

[0029] Furthermore, when arranged vertically, polymer optical waveguides 10 that overlap at least partially in a plan view can be arranged more space-efficiently if the area of ​​overlap between the polymer optical waveguides 10 in a plan view is large. Specifically, they are arranged so that approximately 5 to 70% of the area of ​​the polymer optical waveguides 10 overlaps with each other in a plan view. More preferably, 10 to 60%, and even more preferably, approximately 14 to 40% overlap. This allows for space-efficient arrangement of the polymer optical waveguides while enabling high-density installation of the core 11 on the optical circuit board 30 side. The ratio of the area of ​​overlap between polymer optical waveguides 10 arranged vertically in a plan view is defined as (area of ​​overlapping portion of polymer optical waveguides 10 in a plan view) / (combined area of ​​two polymer optical waveguides 10 arranged vertically).

[0030] Furthermore, when an asymmetric polymer optical waveguide 10 is used as in this embodiment, compared to when a symmetric polymer optical waveguide 10 is used, it is no longer necessary to offset the connectors 20 that are arranged vertically in the width direction, thus increasing the area in which the polymer optical waveguides 10 overlap in a plan view.

[0031] In the above example, the substrate-side ends 10b of the polymer optical waveguides 10 arranged vertically are both connected to the surface of the substrate 30. However, they may also be connected to the back surface of the substrate 30, or one may be connected to the surface of the substrate 30 and the other to the back surface. With this configuration, even with symmetrical polymer optical waveguides 10, the overlapping area in a plan view can be increased, allowing for space-efficient arrangement of the polymer optical waveguides 10. Incidentally, in this embodiment, the polymer optical waveguides 10 arranged vertically are not in contact with each other, but they may be arranged so that a portion of them is in contact.

[0032] <Second Embodiment> Next, the optical module 100A of the second embodiment will be described with reference to Figure 6. Figure 6 is a side view showing the optical module of the second embodiment. The differences in the configuration of the optical module of the second embodiment from the example described above will be explained below.

[0033] The connector 20A has a lower connector 20A1 to which the lower polymer optical waveguide 10 is attached, and an upper connector 20A2 to which the upper polymer optical waveguide 10 is attached. That is, instead of using a single connector 20 as in the first embodiment, one end 10a of the two polymer optical waveguides 10 is attached to the lower connector 20A1 and the other end is attached to the upper connector 20A2.

[0034] Furthermore, as shown in Figure 6, the lower connector 20A1 is positioned below the plane on which the substrate-side coupling portion 31 of the optical circuit board 30 is formed, and the upper connector 20A2 is positioned below the plane on which the substrate-side coupling portion 31 of the optical circuit board 30 is formed. As a result, the lower polymer optical waveguide 10 is curved upward toward the substrate-side end 10b, and the upper polymer optical waveguide 10 is curved downward toward the substrate-side end 10b.

[0035] Furthermore, the lower connector 20A1 and the upper connector 20A2, which are arranged side by side vertically, may be configured to overlap in a plan view, or they may be configured to be offset in the width direction in a plan view. As a result, the irregularly shaped polymer optical waveguides 10, which are arranged side by side vertically and connected to each connector 20A and the optical circuit board 30, may have an asymmetrical or symmetrical shape.

[0036] This configuration allows for greater flexibility in the placement of the optical circuit board 30 and the connector 40, thereby improving versatility.

[0037] <Third Embodiment> Next, the optical module 100B of the third embodiment will be described based on Figure 7. Figure 7 is a plan view showing the optical module of the third embodiment. The differences in the configuration of the optical module of the third embodiment from the example described above will be explained below.

[0038] As shown in Figure 7, the connector 20B is arranged in a wide manner so that the connector-side ends 10a of the irregularly shaped polymer optical waveguide 10, which have different widths at both ends in the longitudinal direction, are mounted side by side in the width direction. As a result, the vertical positions of the two polymer optical waveguides 10 attached to the connector 20B and the substrate-side coupling portion 31 of the optical circuit board 30 are arranged on the same plane. With this configuration, compared to the above embodiment, the vertical width of the entire optical module 100 can be reduced while increasing the mounting density of the cores 11 connected to the optical circuit board 30.

[0039] <Fourth Embodiment> Next, the optical module 100C of the fourth embodiment will be described based on Figures 8 and 9. Figure 8 is a perspective view showing the optical module of the fourth embodiment. Figure 9 is a plan view showing the optical module of the fourth embodiment. The differences in the configuration of the optical module of the fourth embodiment from the example described above will be explained below.

[0040] The optical module 100C shown in FIGS. 8 and 9 includes three polymer optical waveguides 10C arranged side by side in the vertical direction, a connector 20C that supports one end side of each polymer optical waveguide 10C, and an optical circuit board 30 of an optical integrated circuit to which the other end side of the polymer optical waveguide 10C is connected.

[0041] The connector 20C includes a lower connector 20C1, a central connector 20C2, and an upper connector 20C3, and they are arranged so as to overlap each other in the vertical direction.

[0042] The polymer optical waveguide 10C includes a lower optical waveguide 10C1 whose connector-side end 10a is connected to the lower connector 20C1, a middle optical waveguide 10C2 whose connector-side end 10a is connected to the central connector 20C2, and an upper optical waveguide 10C3 whose connector-side end 10a is connected to the upper connector 20C3.

[0043] The lower optical waveguide 10C1 has a deformed portion 10c that curves upward toward the substrate-side end 10b and becomes narrower toward one end side in the width direction. The middle optical waveguide 10C2 has a deformed portion 10c that is formed straight in the vertical direction toward the substrate-side end 10b and becomes narrower toward the center in the width direction. The upper optical waveguide 10C3 has a deformed portion 10c that curves downward toward the substrate-side end 10b and becomes narrower toward the other end side in the width direction.

[0044] According to this configuration, three polymer optical waveguides 10C arranged side by side in the vertical direction can be arranged densely while being efficiently aggregated on one end side of the optical circuit board 30 with space efficiency. Also, the polymer optical waveguides 10C arranged overlapping each other in the vertical direction are not limited to those that are line-symmetric.

[0045] <Fifth Embodiment> Next, the optical module 100D of the fifth embodiment will be described based on FIG. 10. FIG. 10 is a perspective view showing the optical module of the fifth embodiment. Hereinafter, the differences from the above example in the configuration of the optical module of the fifth embodiment will be described.

[0046] The optical module 100D shown in FIG. 10 includes a bifurcated polymer optical waveguide 10D arranged in two vertically, a pair of connectors 20D that support one end side of each polymer optical waveguide 10D, and an optical circuit board 30 of an optical integrated circuit to which the other end side of the polymer optical waveguide 10D is connected.

[0047] The polymer optical waveguide 10D has two connector-side end portions 10a arranged side by side in the width direction and one substrate-side end portion 10b, and is formed such that the two connector-side end portions 10a merge by a deformed portion 10c formed in a Y shape. The two connector-side end portions 10a are respectively connected to a pair of connectors 20D arranged side by side in the width direction.

[0048] In the illustrated example, since the polymer optical waveguide 10D is formed symmetrically with respect to the extending direction, the pair of polymer optical waveguides 10D arranged vertically are arranged shifted in the width direction in a plan view. With this configuration, the substrate-side end portions 10b of the pair of polymer optical waveguides 10D can be arranged side by side at the edge of the optical circuit board 30. Thereby, the cores 11 connected from each connector 20D via the polymer optical waveguide 10D can be connected to the optical circuit board 30 at a higher density.

[0049] Note that the present invention is not limited to the above-described embodiment, and it is also contemplated by the present invention that those skilled in the art make changes and applications based on combinations of each configuration of the embodiment, the description of the specification, and well-known techniques, and are included in the scope for which protection is sought.

[0050] As described above, the following matters are disclosed in this specification: (1) An optical module having a core and a sheet-like cladding including a plurality of the cores arranged side by side in the width direction, wherein the optical waveguide is deformed in the width direction along the longitudinal direction so that the widths of the two ends in the longitudinal direction are different, and a substrate to which one end in the longitudinal direction of the optical waveguide is connected, wherein the two ends in the longitudinal direction of the plurality of optical waveguides are connected within the same plane of the substrate. With this configuration, by connecting optical waveguides with widths of different widths at both ends in the longitudinal direction within the same plane of the substrate, a high density of cores that transmit light to the substrate can be arranged in a simple and low-cost configuration. In addition, the cores of the optical waveguides can be connected to the substrate side in a space-efficient manner.

[0051] (2) The optical module according to (1), wherein the plurality of optical waveguides are arranged such that a portion of the optical waveguides overlaps in a plan view by displacing at least one of the optical waveguides in the vertical direction. With this configuration, a plurality of optical waveguides connected to the same substrate can be installed in a space-efficient manner.

[0052] (3) The optical module according to (1) or (2), wherein the optical waveguide has the shorter end of its longitudinal direction connected to the substrate. With this configuration, multiple optical waveguides connected to the same substrate can be installed in a space-efficient manner. In addition, since multiple cores of the optical waveguide can be connected to the substrate in a smaller installation space, the mounting density of cores connected to the substrate can be increased.

[0053] (4) The optical module according to (3), wherein the cladding extending along the core has a deformed portion whose outer edge shape in the width direction is deformed toward the substrate end, which is the longitudinal end connected to the substrate. With this configuration, the outer edge shape in the width direction of the optical waveguide becomes narrower toward the substrate, so that the optical waveguide can be installed in a space-efficient manner.

[0054] (5) An optical module according to any one of (1) to (4), wherein the bending radius of the optical waveguide that is displaced by curving in the vertical direction is 1 mm or more. With this configuration, the mounting density of cores connected to the substrate can be increased without increasing the connection loss of a single core.

[0055] (6) The optical module according to any one of (1) to (5), wherein the substrate is an optical integrated circuit, and the optical connection method between the optical waveguide and the optical integrated circuit is lattice coupling, evanescent coupling, or direct pair coupling. With this configuration, the core mounting density can be increased, and various coupling methods can be used for connecting the core to the optical fiber or the silicon optical waveguide on the optical integrated circuit side, thus increasing versatility.

[0056] (7) An optical module according to any one of (1) to (6), wherein the other longitudinal ends of a plurality of optical waveguides are connected to optical waveguides or optical fibers using two or more connectors. This configuration expands the range in which multiple optical waveguides connected to the same substrate can be arranged, thereby improving versatility.

[0057] (8) An optical module according to any one of (1) to (6), wherein the other longitudinal ends of a plurality of optical waveguides are connected to an optical waveguide or optical fiber using a single connector. With this configuration, the positioning of the plurality of optical waveguides is made easier and the number of parts can be reduced, thus keeping costs low.

[0058] (9) An optical module according to any one of (2) to (8), wherein the area in a plan view where the optical waveguides arranged in a vertical direction overlap each other is 10% or more of the combined area of ​​the overlapping optical waveguides in a plan view. With this configuration, the optical waveguides arranged vertically can be installed in a space-efficient manner.

[0059] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0060] This application is based on a Japanese patent application (Patent Application No. 2024-223099) filed on December 18, 2024, the contents of which are incorporated by reference within this application.

[0061] 10 Polymer optical waveguide (optical waveguide) 10a Connector side end 10b Substrate side end 10c Deformed part 11 Core 12 Cladding 13 Undercladding 14 Overcladding 15 Projection 20 Connector 28 Guide hole 30 Optical circuit board (substrate) 31 Substrate side coupling part 32 Guide groove 33 Substrate side connection part 100 Optical module

Claims

1. An optical module comprising: a core; a sheet-like cladding containing a plurality of the cores arranged side by side in the width direction, wherein the optical waveguide is deformed in the width direction along the longitudinal direction, resulting in optical waveguides with different widths at both ends in the longitudinal direction; and a substrate to which one end of the optical waveguide in the longitudinal direction is connected, wherein the longitudinal ends of the plurality of optical waveguides are connected within the same plane of the substrate.

2. The optical module according to claim 1, wherein the plurality of optical waveguides are arranged such that a portion of the optical waveguides overlaps in a plan view by displacing at least one of the optical waveguides in the vertical direction.

3. The optical module according to claim 1, wherein the optical waveguide is connected to the substrate at the end with the shorter width in the longitudinal direction.

4. The optical module according to claim 3, wherein the cladding extending along the core has a deformed portion whose outer edge shape in the width direction is deformed toward the substrate-side end, which is the longitudinal end connected to the substrate.

5. The optical module according to claim 1, wherein the bending radius of the optical waveguide that is displaced by curving in the vertical direction is 1 mm or more.

6. The optical module according to claim 1, wherein the substrate is an optical integrated circuit, and the optical connection method between the optical waveguide and the optical integrated circuit is lattice coupling, evanescent coupling, or direct pair coupling.

7. The optical module according to claim 1, wherein the other longitudinal ends of a plurality of optical waveguides are connected to optical waveguides or optical fibers using two or more connectors.

8. The optical module according to claim 1, wherein the other longitudinal ends of a plurality of optical waveguides are connected to optical waveguides or optical fibers using a single connector.

9. The optical module according to claim 2, wherein the area in which the optical waveguides arranged in a vertical direction overlap in a plan view is 10% or more of the combined area of ​​the optical waveguides that overlap in a plan view.

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