Optical module

Abstract

The present invention relates to an optical module having a core (11), a sheet-like cladding (12) containing a plurality of cores arranged side by side in the width direction, and an optical waveguide (10) with different widths at both ends in the longitudinal direction, which is formed by deformation in the width direction along the longitudinal direction, and a substrate (30) to which one end of the optical waveguide in the longitudinal direction is connected, wherein one end of the plurality of optical waveguides (10) in the longitudinal direction is connected within the same plane of the substrate (30).

Description

Technical Field

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

[0002] Silicon photonics, a technology for integrating silicon optical circuits on silicon chips, has attracted attention. In silicon photonics, as disclosed for example in Patent Document 1, an optical waveguide is known as a waveguide that transmits optical signals 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 than in optical fibers.

[0003] Patent Document 2 discloses a configuration of an optical connector and an optical transmission module that transmits light transmitted from an optical fiber to a substrate side at high density, the configuration including: 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. Prior Art Documents Patent Documents

[0004] Patent Document 1 Japanese Unexamined Patent Publication No. 2014-81586 Patent Document 2 Japanese Unexamined Patent Publication No. 2017-134282 Summary of the Invention Problems to be Solved by the Invention

[0005] Patent Document 2 aims to increase the mounting density of optical fibers connected to an optical integrated circuit by reflecting light emitted from multiple optical fibers arranged two-dimensionally in two rows in the vertical direction toward the same plane on the substrate. However, this requires high-precision attachment of the optical fibers to the optical connector, and a lens corresponding to each optical fiber is required, resulting in a large number of parts, which presents challenges in terms of workability and cost during assembly. Furthermore, since only vertical coupling and lattice coupling can be used as means of transmitting optical signals to the silicon optical waveguide provided on the substrate side of the optical integrated circuit, versatility is also a challenge.

[0006] The present invention has been made in view of the above circumstances, and its objective is to provide an optical module that enables high-density mounting of light-transmitting cores on a substrate of an optical integrated circuit in a simple and low-cost configuration, and enables space-efficient connection of the cores to a silicon optical waveguide provided in the optical integrated circuit. [Means for solving the problem]

[0007] The above objective of the present invention is achieved by the following configuration. (1) A light waveguide having a core and a sheet-like cladding including a plurality of the cores arranged side by side in the width direction, which deforms in the width direction along the longitudinal direction, thereby having different widths at both ends in the longitudinal direction, The optical waveguide has a substrate to which one longitudinal end is connected, The longitudinal ends of the multiple optical waveguides are connected within the same plane of the substrate. Optical module. [Effects of the Invention]

[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. [Brief explanation of the drawing]

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

[0010] <First Embodiment> Hereinafter, preferred embodiments of the optical module of the present invention, as shown in the accompanying 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 FIG. 1 includes a pair of upper and lower polymer optical waveguides 10, a connector 20 that supports one end side of the polymer optical waveguides 10, and an optical circuit board 30 of an optical integrated circuit to which the other end side of the polymer optical waveguides 10 is connected.

[0012] (Polymer Optical Waveguide 10) As shown in FIG. 1, the polymer optical waveguide 10 includes a core 11 that transmits light and a sheet-shaped cladding 12 that houses the core 11, and is a sheet-shaped deformed optical waveguide having different widths at both ends in the longitudinal direction depending on the outer edge shape in the width direction of the cladding 12. Further, as shown in FIG. 1 and FIG. 2, the polymer optical waveguide 10 includes a connector-side end portion 10a connected to the connector side, a substrate-side end portion 10b formed to be narrower than the connector-side end portion 10a and connected to the optical circuit board 30 side, and a deformed portion 10c whose outer edge shape in the width direction deforms so that the width narrows from the connector-side end portion 10a toward the substrate-side end portion 10b. In the present embodiment, the deformed portion 10c is a portion obtained by curving one side in the width direction of the cladding 12 into an S-shape from the connector-side end portion 10a toward the substrate-side end portion 10b. The other end side in the width direction of the cladding 12 is formed straight along the longitudinal direction. Note that the shape of the deformed portion 10c is not limited to the illustrated shape, and may be formed at both ends in the width direction of the cladding 12.

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

[0014] As shown in FIGS. 1 to 3, two polymer optical waveguides 10 are arranged vertically side by side between the connector 20 and the optical circuit board 30. As shown in FIGS. 1 and 2, the upper and lower polymer optical waveguides 10 are arranged such that portions thereof near the connector-side end portions 10a overlap each other in a plan view, and extend in different directions in the width direction via deformed portions 10c so that the substrate-side end portion 10b sides do not overlap each other in a plan view. As shown in FIG. 3, the lower polymer optical waveguide 10 is arranged without being displaced in the vertical direction from the connector 20 toward the optical circuit board 30, while the upper polymer optical waveguide 10 has a middle portion in the longitudinal direction curved downward from the connector 20 toward the optical circuit board 30.

[0015] Thereby, in a state where the pair of upper and lower polymer optical waveguides 10 are arranged such that at least a part thereof overlaps in a plan view, the connector-side end portions 10a are attached to the connector 20. On the other hand, the substrate-side end portions 10b of the pair of upper and lower polymer optical waveguides 10 are respectively connected to substrate-side coupling portions 31 formed side by side in the width direction on the same plane of the optical circuit board 30.

[0016] Note that the number of polymer optical waveguides 10 arranged between the connector 20 and the optical circuit board 30 only needs to be 2 or more, and is not limited to two. Further, for the plurality of polymer optical waveguides 10, it is only required that the substrate-side end portions 10b are connected to the same plane of the optical circuit board 30, two or more polymer optical waveguides 10 may be displaced in the vertical direction, or all of the polymer optical waveguides 10 may not be displaced in the vertical direction.

[0017] As shown in FIG. 4, the clad 12 of the polymer optical waveguide 10 includes an underclad 13 and an overclad 14. The underclad 13 has a lower refractive index than the core 11, and is present around the core 11. The overclad 14 has a lower refractive index than the core 11, and is present around the core 11 on the opposite side from the underclad 13.

[0018] In the polymer optical waveguide 10 of this embodiment, multiple cores 11 arranged in a line in the width direction on the plane of a sheet-like underclad 13 are covered by a sheet-like overclad 14 on all sides (outside in the width direction and one side in the vertical direction). 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, 12 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 shape shown. The distance between adjacent cores 11 within the overcladding 14 is made larger than the mode field diameter, which is determined by the size of the cores 11 and the difference in refractive index between the cores 11 and the cladding 12. This allows for a high density arrangement of cores 11 within the cladding 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 to between 10 μm and 100 μm. However, 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 undercladding 13 and overcladding 14, was made greater than half the mode field diameter. This prevents light from leaking out of the undercladding 13 and overcladding 14, which would increase the propagation loss in the core 11. The mode field diameter was set to 1 μm or larger. The core height h of core 11 is set to be between 0.1 μm and 50 μm, with a more preferable core height h being between 0.5 μm and 30 μm. The core width of core 11 is set to be between 0.5 μm and 50 μm, with a more preferable core width being between 1 μm and 30 μm. With this configuration, the yield of the manufactured polymer optical waveguides is increased, as is the mounting density of core 11. In this specification, "core width" refers to the width of the core in a cross section perpendicular to the direction of light propagation in the polymer optical waveguide, in the direction perpendicular to the thickness direction of the polymer optical waveguide. "Core height" refers to the height of the core in a cross section perpendicular to the direction of light propagation in the polymer optical waveguide, in the direction perpendicular to the direction of light propagation in the polymer optical waveguide.

[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 that constitutes 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 waveguide 10 can be connected on the same plane. The optical circuit board 30 is a substrate on which general modules that constitute 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. The multiple substrate-side coupling portions 31 are arranged side by side along 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 recessed linearly from the edge 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 is formed in a trapezoidal shape with a pair of inclined surfaces and a bottom, and has 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 the projection 15 formed by the substrate-side end 10b of the overcladding 14 that constitutes the polymer optical waveguide 10, as shown in Figure 5. According to 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 of the optical circuit board 30. Furthermore, with the above configuration, lattice coupling, evanescent coupling, or direct pair 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 substrate 30 side.

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

[0027] (Mechanism of action and effects) In 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 respectively connected to substrate-side coupling portions 31 which are arranged side by side on the same plane of the optical circuit board 30. According to this configuration, multiple cores 11 contained in two polymer optical waveguides 10 formed narrowly 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 portion 31 formed on the same plane. As a result, the cores 11 of the polymer optical waveguide 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-like polymer optical waveguides 10, which are supported vertically 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. According to this configuration, multiple polymer optical waveguides 10 connected to the same plane of the optical circuit board 30 can be arranged in a state where they are stacked vertically, thus allowing for more space-efficient installation of multiple polymer optical waveguides 10.

[0029] Furthermore, because they are arranged side by side in the vertical direction, the polymer optical waveguides 10 that overlap at least partially in a plan view can be arranged more space-efficiently as the area of ​​overlap between the polymer optical waveguides 10 in a plan view increases. Specifically, the polymer optical waveguides 10 are arranged so that approximately 5-70% of their area overlaps when viewed from above. More preferably, 10-60%, and even more preferably, 14-40% overlap. This allows for space-efficient arrangement of the polymer optical waveguides while enabling high-density placement of the cores 11 on the optical circuit board 30 side. The ratio of the overlapping area of ​​two polymer optical waveguides 10 arranged vertically in a plan view was calculated as (area of ​​the overlapping portion of the 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 positioned vertically in the width direction, thus increasing the area in which the polymer optical waveguides 10 overlap in a plan view.

[0031] In the example described above, 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 of the substrate 30. 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 based on 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 compared to the example described above will be explained below.

[0033] The connector 20A includes 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. In other words, instead of attaching the connector-side ends 10a of the two polymer optical waveguides 10 to a single connector 20 as in the first embodiment, one end is attached to the lower connector 20A1 and the other end 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. above They are positioned on the side. 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 asymmetrical or symmetrical shapes.

[0036] According to this configuration, the optical circuit board 30 and the connector 20A The increased flexibility in placement improves 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 configuration 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, can be attached 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 located on the same plane. With this configuration, compared to the above-described embodiment, the overall vertical width of the 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 Figures 8 and 9 comprises three polymer optical waveguides 10C arranged in a vertical direction, a connector 20C supporting one end of each polymer optical waveguide 10C, and an optical circuit board 30 of an optical integrated circuit to which the other ends of the polymer optical waveguides 10C are connected.

[0041] Connector 20C has a lower connector 20C1, a central connector 20C2, and an upper connector 20C3, which are arranged side by side and overlap 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 narrows toward one end in the width direction. The medium optical waveguide 10C2 has a straight vertical section formed toward 10b at the substrate-side end, and a deformed section 10c that narrows 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 narrows toward the other end in the width direction.

[0044] According to this configuration, three polymer optical waveguides 10C arranged vertically can be densely arranged on one end of the optical circuit board 30 while efficiently concentrating them in space. Furthermore, the polymer optical waveguides 10C arranged in the vertical direction are not limited to being symmetrical.

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

[0046] The optical module 100D shown in Figure 10 comprises two bifurcated polymer optical waveguides 10D arranged side by side in the vertical direction, a pair of connectors 20D supporting one end of each polymer optical waveguide 10D, and an optical circuit board 30 of an optical integrated circuit to which the other ends of the polymer optical waveguides 10D are connected.

[0047] The polymer optical waveguide 10D has two connector-side ends 10a and one substrate-side end 10b arranged side by side in the width direction, and is formed so that the two connector-side ends 10a merge with a Y-shaped deformation portion 10c. The two connector-side ends 10a are each connected to a pair of connectors 20D that are 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 direction of extension, the pair of polymer optical waveguides 10D arranged vertically are offset in the width direction when viewed from above. This configuration allows the substrate-side ends 10b of a pair of polymer optical waveguides 10D to be arranged side by side along the edge of the optical circuit board 30. This enables the cores 11 connected from each connector 20D via the polymer optical waveguides 10D to be connected to the optical circuit board 30 at a higher density.

[0049] It should be noted that the present invention is not limited to the embodiments described above. Combining the various components of the embodiments with each other, and modifying and applying them based on the description in the specification and well-known technology, are also intended to be done by those skilled in the art and are included within the scope of protection.

[0050] As described above, the following matters are disclosed in this specification: (1) A light waveguide having a core and a sheet-like cladding including a plurality of the cores arranged side by side in the width direction, which deforms in the width direction along the longitudinal direction, thereby having different widths at both ends in the longitudinal direction, The optical waveguide has a substrate to which one longitudinal end is connected, The longitudinal ends of the multiple optical waveguides are connected within the same plane of the substrate. Optical module. This configuration allows for a high-density arrangement of light-transmitting cores on a substrate in a simple and low-cost manner by connecting optical waveguides with different widths at both ends along their longitudinal direction within the same plane of the substrate. Furthermore, the optical waveguide cores can be connected to the substrate side in a space-efficient manner.

[0051] (2) 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. (1) The optical module described above. This configuration allows for space-efficient installation of multiple optical waveguides connected to the same substrate.

[0052] (3) The optical waveguide is connected to the substrate at the end with the shorter width in the longitudinal direction. The optical module described in (1) or (2). This configuration allows for space-efficient installation of multiple optical waveguides connected to the same substrate. Furthermore, because multiple cores of the optical waveguides 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 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, (3) The optical module described above. With this configuration, the outer edge shape of the optical waveguide in the width direction narrows towards the substrate, allowing the optical waveguide to be installed in a space-efficient manner.

[0054] (5) The bending radius of the optical waveguide that is displaced by curving in the vertical direction is 1 mm or more. The optical module described in any one of (1) to (4). This configuration allows for increased core mounting density on the board without increasing the connection loss of a single core.

[0055] (6) The substrate is an optical integrated circuit, The optical connection method between the optical waveguide and the optical integrated circuit is lattice coupling, evanescent coupling, or direct pair coupling. The optical module described in any one of (1) to (5). This configuration allows for increased core implementation density while also enabling various coupling methods for connecting the core to the optical fiber or silicon optical waveguide on the integrated circuit side, thus increasing versatility.

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

[0057] (8) The other longitudinal ends of the multiple optical waveguides are connected to an optical waveguide or optical fiber using a single connector. The optical module described in any one of (1) to (6). This configuration facilitates the positioning of multiple optical waveguides and reduces the number of components, thereby keeping costs low.

[0058] (9) 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. The optical module described in any one of (2) to (8). This configuration allows for space-efficient installation of optical waveguides positioned vertically.

[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. [Explanation of Symbols]

[0061] 10. Polymer Optical Waveguides (Optical Waveguides) 10a Connector side end 10b Board side edge 10c Deformed part 11 cores 12 clad 13 Underclad 14 Overclad 15 Protrusion 20 connectors 28 guide holes 30 Optical circuit board (substrate) 31 Substrate-side bonding portion 32 guide grooves 33. Circuit board side connection part 100 optical modules

Claims

1. A plurality of optical waveguides having a core and a sheet-like cladding including a plurality of the cores arranged side by side in the width direction, The plurality of optical waveguides have a substrate to which one longitudinal end is connected, The cladding has a deformed portion in which the outer edge shape in the width direction deforms toward the substrate-side end, which is one end in the longitudinal direction, so that the width of the one end in the longitudinal direction is shorter than the width of the other end in the longitudinal direction. Each of the multiple optical waveguides has one longitudinal end connected to a substrate-side coupling portion arranged on the same plane of the substrate along one side forming the outer edge of the substrate. Of the plurality of optical waveguides, at least two of the optical waveguides are arranged side by side in the vertical direction, and at least one of the optical waveguides is curved such that it is displaced vertically in the middle of its longitudinal direction. The at least two optical waveguides are arranged such that a portion of them near the other end in the longitudinal direction overlaps with each other in a plan view, and the deformed portion extends in different directions in the width direction such that the portions near the one end in the longitudinal direction do not overlap with each other in a plan view. Optical module.

2. The optical waveguide has a projection formed on one end in the longitudinal direction, The substrate-side coupling portion has a guide groove into which the projection fits. The optical module according to claim 1.

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

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

5. The other ends in the longitudinal direction of multiple optical waveguides are connected to optical waveguides or optical fibers using two or more connectors. The optical module according to claim 1.

6. The other longitudinal ends of multiple optical waveguides are connected to optical waveguides or optical fibers using a single connector. The optical module according to claim 1.

7. The area in which the optical waveguides arranged vertically overlap in a plan view is set to be 5% or more of the combined area of ​​the overlapping optical waveguides in a plan view. The optical module according to claim 1.

8. In each of the plurality of optical waveguides, the distance between adjacent cores at the substrate-side end is 10 μm or more and 100 μm or less. The optical module according to claim 1.

9. Each of the plurality of cores has a core height of 0.1 μm or more and 50 μm or less, and a core width of 0.5 μm or more and 50 μm or less. The optical module according to claim 1.

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