Optical connector and optical connector module

Abstract

A light connector (20) of the present disclosure, which is mounted to an optical transmission path (10) having a base (11) and an optical waveguide section (12) laminated to the base (11), the light connector (20) includes: a first side surface (A1) that opposes an end surface of the optical transmission path (10); a second side surface (A2) that is located on an opposite side of the first side surface (A1) in a propagation direction of light; at least one first lens (225) that is formed in the first side surface (A1) and opposes the end surface of the optical waveguide section (12); and a plurality of second lenses (226) that are formed in the second side surface (A2) at positions that oppose the first lens (225) in the propagation direction, and the number of the first lenses (225) is less than the number of the second lenses (226).

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Japanese Patent Application No. 2020-128660, dated July 29, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to optical connectors and optical connector modules. Background Technology

[0004] Optical connectors for optically coupling optical transmission paths to each other are known in the past. For example, Patent Document 1 discloses an optical connector that can reduce coupling loss and facilitate miniaturization.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Invention Patent No. 6401888 Summary of the Invention

[0008] One embodiment of the present disclosure provides an optical connector that is mounted to an optical transmission path having a substrate and an optical waveguide portion stacked on the substrate. The optical connector comprises:

[0009] The first side face is opposite to the end face of the optical transmission path;

[0010] The second side is located on the opposite side of the first side in the direction of light propagation;

[0011] At least one first lens is formed on the first side surface and faces the end face of the optical waveguide portion;

[0012] A plurality of second lenses are formed in the second side surface at a position opposite to the first lens in the propagation direction;

[0013] The number of the first lens is less than the number of the second lens.

[0014] One embodiment of the optical connector module disclosed herein includes:

[0015] The aforementioned optical connector;

[0016] A refractive index matching agent is positioned between the end face of the light transmission path and the first side face to adjust the refractive index. Attached Figure Description

[0017] Figure 1 This is a top-down perspective view showing the appearance of an optical connector module containing one embodiment of the optical connector.

[0018] Figure 2 It is a magnified representation from a top-down perspective. Figure 1 A three-dimensional view of the optical transmission path component.

[0019] Figure 3 It means Figure 1 A three-dimensional view of the appearance of a single optical connector component.

[0020] Figure 4 It is a schematic representation from the front. Figure 1 A cross-sectional view of the optical connector module.

[0021] Figure 5 yes Figure 1 A sectional view along the V-V arrow line.

[0022] Figure 6 It is magnification Figure 5 Enlarged view of section VI within the dashed box.

[0023] Figure 7 It is a further amplification Figure 6 Enlarged view of section VII within the dashed box.

[0024] Figure 8 yes Figure 1 An enlarged sectional view along the arrow line VIII-VIII.

[0025] Figure 9A This means that in the absence of a refractive index matching agent, in Figure 8 A schematic diagram of the shape of light propagating in the end channel.

[0026] Figure 9B This means that in the absence of a refractive index matching agent, in Figure 8 A schematic diagram of the shape of light propagating in the central channel.

[0027] Figure 10A In the presence of a refractive index matching agent, and with Figure 9A The corresponding diagram.

[0028] Figure 10B In the presence of a refractive index matching agent, and with Figure 9B The corresponding diagram.

[0029] Figure 11 This represents a variation of the optical connector module, and... Figure 8 The corresponding enlarged sectional view. Detailed Implementation

[0030] In the optical connector described in Patent Document 1, the number of first lenses constituting the first lens section and the number of second lenses constituting the second lens section are the same as the number of fiber cores constituting the optical transmission path. Thus, with a one-to-one correspondence between the first and second lenses, the performance of the optical connector is affected by the properties of the materials constituting the connector. For example, when the optical connector has multiple lenses formed of resin material, warping and shrinkage of components during manufacturing make it difficult to mold each lens and achieve high-precision optical axis alignment between the first and second lenses. As a result, the optical axes of the first and second lenses are misaligned, making it difficult to obtain the desired high-precision optical characteristics.

[0031] According to one embodiment of the optical connector and optical connector module of this disclosure, even with a first lens and a second lens, the desired high-precision optical characteristics can be easily obtained.

[0032] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. The directions of front-back, left-right, and up-down in the following description are based on the directions of the arrows in the drawings. Figures 1 to 10B In the diagram, the directions of the arrows are consistent with each other in different attached diagrams.

[0033] In this specification, "direction of light propagation" includes, for example, the front-back direction. "First direction orthogonal to the direction of light propagation" includes, for example, the left-right direction. "Second direction orthogonal to both the direction of light propagation and the first direction" includes, for example, the up-down direction. However, this is not a limitation; the first direction orthogonal to the direction of light propagation may include the up-down direction, and the second direction orthogonal to both the direction of light propagation and the first direction may include the left-right direction.

[0034] Figure 1 This is a top-down perspective view showing the external appearance of an optical connector module 1 including an optical connector 20 according to one embodiment. (Refer to...) Figure 1 This section provides an overview of the structure and function of the optical connector module 1.

[0035] The optical connector module 1 has an optical transmission path 10, an optical connector 20 optically coupled to the optical transmission path 10, and a refractive index matching agent 30 for adjusting the first space S1 between the optical transmission path 10 and the optical connector 20.

[0036] The optical connector 20 is installed onto the optical transmission path 10 according to an installation method comprising multiple steps. The installation method includes, for example, a first step of positioning the optical connector 20 in a state where it is placed on the optical transmission path 10.

[0037] The installation method includes, for example, a second step, in which, such as... Figure 1As indicated by the left-right arrows, an adhesive is applied from both sides of the optical connector 20, which is positioned in the first step, towards the space between the optical connector 20 and the optical transmission path 10. The second step is a step for securing the optical connector 20 to the optical transmission path 10 using this adhesive. In this specification, "adhesive" includes, for example, any filler with adhesive properties. For example, the adhesive includes an adhesive.

[0038] The installation method includes, for example, a third step, in which, such as... Figure 1 As indicated by the upward-pointing arrow, the refractive index matching agent 30 flows from below the optical connector 20, which is fixed to the optical transmission path 10 in the second step, into the first space S1 formed between the optical transmission path 10 and the optical connector 20. The refractive index matching agent 30 has both an adhesive function for fixing the optical connector 20 to the optical transmission path 10 and a function for adjusting the refractive index in the first space S1. The third step is a step for fixing the optical connector 20 to the optical transmission path 10 using this refractive index matching agent 30.

[0039] Optical connector module 1 optically couples with other optical transmission paths, such as optical fibers and optical waveguides. For example, in optical connector module 1, optical coupling between optical transmission path 10 and optical fiber is achieved by connecting optical connector 20, which is mounted to optical transmission path 10, and ferrules that hold the optical fiber together. For example, optical connector module 1 can achieve optical coupling between optical transmission path 10 and optical waveguide by connecting optical connector 20, which is mounted to optical transmission path 10, to other optical connectors similarly mounted to optical waveguides.

[0040] Figure 2 It is a magnified representation from a top-down perspective. Figure 1 A three-dimensional view of the optical transmission path component 10. (Refer to...) Figure 2 The structure of the optical transmission path 10 will be described in detail. In one embodiment, the optical transmission path 10 has a substrate 11 and an optical waveguide portion 12 stacked on the substrate 11.

[0041] The optical transmission path 10, for example, has a substrate 11 made of a rigid printed wiring board and an optical waveguide portion 12 stacked on the upper surface of the substrate 11. The optical waveguide portion 12 is formed in a U-shape, for example, projecting upwards from the upper surface of the substrate 11. The optical waveguide portion 12 is formed such that its end face coincides with the end face of the substrate 11 for optical coupling with the optical connector 20. The end face of the optical waveguide portion 12 is formed in a planar shape, for example, along the end face of the substrate 11. The waveguide mode of the optical waveguide portion 12 can be either single-mode or multi-mode.

[0042] The optical waveguide 12 has a fiber core 121 and a cladding 122 stacked on the substrate 11 in a stacking direction orthogonal to the substrate 11. More specifically, the optical waveguide 12 has a first cladding 122a stacked on the upper surface of the substrate 11, a fiber core 121 stacked on the first cladding 122a, and a second cladding 122b sandwiched together with the first cladding 122a in the stacking direction and surrounding the fiber core 121.

[0043] Multiple fiber cores 121 are formed such that they are separated from each other at predetermined intervals in the left-right direction. Each fiber core 121 extends in the front-back direction. The fiber cores 121 and the cladding 122 are formed of a suitable material, such as quartz glass. The refractive index of the fiber cores 121 is higher than that of the cladding 122. Hereinafter, the optical waveguide 12 is described as an example of an embedded type optical waveguide, but it is not limited to this. The optical waveguide 12 can be a planar type or a semi-embedded type optical waveguide, etc.

[0044] When the waveguide mode of the optical waveguide section 12 is single-mode, the core size of the fiber core 121 is, for example, in the range of 5 μm or more and 15 μm or less. When the waveguide mode of the optical waveguide section 12 is multimode, the core size of the fiber core 121 is, for example, 35 μm or more and 62.5 μm or less. In this specification, "fiber core" includes, for example, the actual size of the fiber core 121 and not the mode field diameter. The refractive index of the fiber core 121 is, for example, 1.6.

[0045] The optical transmission path 10 is manufactured, for example, using photolithography. The manufacturing method is performed in the order of the first cladding 122a, the fiber core 121, and the second cladding 122b. The manufacturing method of the optical transmission path 10 includes a step of laminating the first cladding 122a constituting the optical waveguide portion 12 onto the substrate 11 along a lamination direction orthogonal to the substrate 11. The manufacturing method of the optical transmission path 10 includes a step of laminating the fiber core 121 constituting the optical waveguide portion 12 onto the first cladding 122a. The manufacturing method of the optical transmission path 10 includes a step of laminating the second cladding 122b constituting the optical waveguide portion 12 together with the first cladding 122a in a manner in which the fiber core 121 is sandwiched between them in the lamination direction.

[0046] Figure 3 It means Figure 1 A perspective view of the external appearance of a single optical connector 20. (Refer to...) Figure 3 Mainly for Figure 1 An example of the structure of the optical connector 20 is given to illustrate this.

[0047] The optical connector 20 is formed in an L-shape, for example, from a light-transmitting resin material. The first lens unit 225 (hereinafter simply referred to as the first lens), formed on the first side surface A1 opposite to the end face of the light transmission path 10, and the second lens unit 226 (hereinafter simply referred to as the second lens), formed on the second side surface A2 opposite to the first side surface A1, are also formed, for example, from a light-transmitting resin material. For example, the optical connector 20 is formed from a material having a refractive index similar to that of the fiber core 121 of the optical waveguide portion 12.

[0048] The material of the optical connector 20 includes, for example, polyetherimide (PEI). However, it is not limited to this; the material of the optical connector 20 may also include any other resin material such as polycarbonate (PC) and polymethyl methacrylate (PMMA). The refractive index of the optical connector 20 is, for example, in the range of 1.4 or higher and 1.7 or lower. The refractive index of the optical connector 20 varies depending on the wavelength of the propagating light and the temperature. Furthermore, the material of the optical connector 20 may also include materials other than resin materials. In this case, the first lens 225 and the second lens 226 of the optical connector 20, described later, may also be formed of materials other than resin materials.

[0049] The optical connector 20 has a first base 21 extending in the front-rear direction. The optical connector 20 has a lower surface 211, which is coplanar with the lower surface of the sidewall 215 (described later) in the first base 21. The optical connector 20 has a recess 212, which is recessed further inward from the center of the lower surface 211 in the left-right direction towards the upper direction of the first base 21.

[0050] The optical connector 20 has an abutment portion 213 that protrudes further outward in a vertical direction from the lower surface 211 of the first base 21. The abutment portion 213 is located on the left and right sides relative to the recess 212. The abutment portion 213 includes an abutment surface 213a located at the lowermost part in the downward direction of the first base 21, i.e., the distal end of the first base 21. The abutment surface 213a is formed in the first base 21 at the most protruding position on the side towards the optical transmission path 10. The abutment surface 213a forms the lower distal surface in the first base 21. The abutment portion 213 and the abutment surface 213a extend in a front-rear direction across substantially the entire first base 21.

[0051] The optical connector 20 has a first adhesive portion 214, which is formed in a first base 21 in a region different from the abutment portion 213. The first adhesive portion 214 includes a portion of the lower surface 211 of the first base 21. The first adhesive portion 214 is located laterally than the abutment portion 213, on either side of the recess 212. The first adhesive portion 214 includes an adhesive surface 214a, which is located in the first base 21 in an upper direction, i.e., more inner, relative to the abutment surface 213a. The adhesive surface 214a is located on the opposite side of the optical transmission path 10 in the first base 21 relative to the abutment surface 213a. In the first base 21, the area of ​​the adhesive surface 214a is larger than the area of ​​the abutment surface 213a. The first adhesive portion 214 and the adhesive surface 214a extend across the entire first base 21 in the front-rear direction.

[0052] The optical connector 20 has a sidewall 215 forming a side end portion of the first base 21. The sidewall 215 is located on the left and right sides relative to the recess 212. A first adhesive portion 214 is formed on the sidewall 215. The adhesive surface 214a of the first adhesive portion 214 forms part of the lower surface 211 of the sidewall 215. The sidewall 215 protrudes to both sides in the left and right direction relative to the second base 22 described later. The sidewall 215 extends across the entire first base 21 in the front-back direction at the side end portion of the first base 21.

[0053] The optical connector 20 has a clearance recess 216, which is formed in the first base 21 to separate the abutment portion 213 and the first adhesive portion 214. The clearance recess 216 is formed in a groove shape, for example, as a clearance groove. The clearance recess 216 is sandwiched between the abutment portion 213 and the first adhesive portion 214, and is located on the left and right sides relative to the recess 212. The clearance recess 216 extends across the entire first base 21 in the front-back direction.

[0054] The optical connector 20 has a positioning portion 217, which is recessed into the first base 21 such that it, together with the sidewall 215, sandwiches the abutment portion 213. From another viewpoint, the positioning portion 217 is recessed in the center of the abutment portion 213. The positioning portion 217 is located on the left and right sides relative to the recess 212. The positioning portion 217 extends across the entire first base 21 in the front-rear direction. The positioning portion 217 is continuously formed from the through hole 221 of the second base 22 (described later) to the rear end of the first base 21. The positioning portion 217 is a semi-circular recess in cross-sectional view. The through hole 221 and the positioning portion 217 are formed concentrically.

[0055] The optical connector 20 has a second base 22, which is L-shaped and extends from the first base 21 in a direction orthogonal to the extending direction of the first base 21. The second base 22 is formed to protrude forward toward the first base 21 and is continuous with the first base 21. The second base 22 is formed to extend downward from the first base 21. A first side surface A1 and a second side surface A2, described later, are formed on the second base 22.

[0056] The optical connector 20 has a circular through hole 221 that extends from the front surface to the rear surface of the second base 22 in cross-sectional view. The through hole 221 is formed at the left and right ends of the second base 22 in such a way that it corresponds to the positioning portion 217 of the first base 21 and is located on the left and right sides relative to the recess 212 of the first base 21.

[0057] The optical connector 20 has a first cutout portion 222 that cuts from the inner surface, i.e., the rear surface, of the second base portion 22 to the first side surface A1. The first cutout portion 222 is formed in a concave shape. The optical connector 20 has a second adhesive portion 223, which is composed of four sides forming the first cutout portion 222 (top, bottom, left, and right), the first side surface A1, and the inner surface of the second base portion 22 located directly below the first cutout portion 222.

[0058] The optical connector 20 has a second cutout portion 224 that cuts from the outer surface, i.e. the front surface, of the second base 22 to the second side surface A2. The second cutout portion 224 is formed in a concave shape.

[0059] The optical connector 20 has, for example, one first lens 225, which is formed with a large radius of curvature across a substantially entire portion of a first side surface A1 that forms part of the first notch 222 in the left-right direction. For example, the first lens 225 is a single lens with a gentle curvature along the left-right direction on the first side surface A1. For example, the number of first lenses 225 differs from the number of fiber cores 121 in the optical transmission path 10, with only one formed. The number of first lenses 225 is less than the number of second lenses 226 described later.

[0060] The optical connector 20 has a plurality of second lenses 226, which are formed on a second side A2 that constitutes part of the second notch 224 and is located on the opposite side of the first side A1 in the direction of light propagation. The plurality of second lenses 226 are arranged in a row in a first direction orthogonal to the direction of light propagation. The plurality of second lenses 226 are formed across approximately the entire second side A2 in the left-right direction. Each second lens 226 is formed on the second side A2 at a position opposite to the first lens 225 in the direction of light propagation. The second lens 226 is a lens having a radius of curvature that is sufficiently smaller than that of the first lens 225. The number of second lenses 226 corresponds to the fiber core 121 of the optical transmission path 10.

[0061] Figure 4 It is a schematic representation from the front. Figure 1 A cross-sectional view of the optical connector module 1. (Refer to...) Figure 4 This section mainly describes the structure and function of the optical connector 20 related to the optical transmission path 10.

[0062] In the first step of the above-described installation method, after the optical connector 20 is placed onto the optical waveguide 12 from above the optical transmission path 10, the first base 21 is placed onto the optical transmission path 10. For example, the abutment portion 213 formed in the first base 21 abuts against the mounting surface of the optical transmission path 10. For example, the abutment surface 213a formed in the first base 21 as the distal surface abuts against the upper surface of the first cladding 122a of the optical waveguide 12.

[0063] Thus, the position of the optical connector 20 relative to the optical transmission path 10 in the vertical direction is determined based on the contact between the contact surface 213a of the first base 21 and the upper surface of the first cladding 122a of the optical waveguide 12.

[0064] Furthermore, in the first step of the above-described installation method, the optical connector 20 can also be positioned relative to the optical transmission path 10 in the front-back and left-right directions by an appropriate method. For example, the optical connector 20 can also be positioned in the front-back and left-right directions by engaging the positioning part 217 with the stud pin formed in the first cladding layer 122a.

[0065] The first adhesive portion 214 separates from the surface of the optical transmission path 10. For example, the adhesive surface 214a, located more inner than the abutment surface 213a in the first base 21, separates from the upper surface of the first cladding layer 122a of the optical waveguide portion 12. At this time, a second space S2 is formed between the first adhesive portion 214 and the surface of the optical transmission path 10, and an agent A for mounting the optical connector 20 to the optical transmission path 10 is inserted into the second space S2. The second space S2 is surrounded by the surface of the optical transmission path 10, the adhesive surface 214a, and the abutment portion 213. More specifically, the second space S2 is surrounded by the upper surface of the first cladding layer 122a, the adhesive surface 214a, and the outer walls of the abutment portion 213 in the left-right direction.

[0066] In the second step of the above-described installation method, the filler A is filled from both sides of the optical connector 20 into the second space S2 formed between the optical connector 20 and the optical transmission path 10. At this time, the filler A forms an inset F near the corner C of the sidewall 215 of the optical connector 20. Even assuming that there is an excess of filler A, the remaining portion of filler A will be accommodated in the clearance recess 216.

[0067] As described above, in the second step of coating agent A, the optical connector 20 is fixed to the optical transmission path 10 by agent A. At this time, the adhesive surface 214a of the optical connector 20 is bonded to agent A. Similarly, the upper surface of the first cladding layer 122a of the optical transmission path 10 is bonded to agent A.

[0068] Figure 5 yes Figure 1 A sectional view along the V-V arrow line. Figure 6 It is magnification Figure 5 Enlarged view of section VI within the dashed box. Figure 7 It is a further amplification Figure 6 An enlarged view of section VII within the dashed box. (Refer to...) Figures 5 to 7 This section mainly describes the structure and function related to the refractive index matching agent 30, as well as the optical function of the optical connector 20.

[0069] like Figure 1 As shown, the optical connector 20 is mounted on the optical waveguide portion 12 above the optical transmission path 10. The optical connector 20 is configured such that its first base 21 abuts against the upper surface of the optical waveguide portion 12 and covers a portion of the optical transmission path 10. The second base 22 is configured to protrude forward from the end of the base 11 and extend downward from the first base 21. The second base 22 protrudes downward with its lower surface positioned lower than the vertical position of the optical waveguide portion 12. The second base 22 is opposite to the end face of the optical transmission path 10, which is orthogonal to the surface of the optical transmission path 10, i.e., the upper surface.

[0070] At this time, as Figure 5 As shown, a first space S1 is formed between the optical transmission path 10 and the optical connector 20. The inner surface of the second base 22 of the optical connector 20, where the first cutout 222 is formed, is separated from the end face of the base 11.

[0071] In the third step of the above-described installation method, the refractive index matching agent 30 is filled from below to completely fill the first space S1. The refractive index matching agent 30 is made of a material having a refractive index approximately similar to that of the fiber core 121 of the light transmission path 10. The material of the refractive index matching agent 30 can be determined to be an optimal material suitable for the refractive index of the fiber core 121 of the light transmission path 10.

[0072] The material of the refractive index matching agent 30 may include, for example, a polymer. The refractive index matching agent 30 may also be a so-called matching oil. The refractive index of the refractive index matching agent 30 is, for example, in the range of 1.3 or higher and 1.8 or lower. The refractive index of the refractive index matching agent 30 varies depending on the wavelength of the propagating light and the temperature.

[0073] For example, the refractive index n1 of the optical connector 20 and the refractive index n2 of the refractive index matching agent 30 have a relationship as shown in Equation 1 below. The difference between the refractive index n1 and the refractive index n2 is within 15% of the refractive index n2. In this case, the value of the refractive index n1 is greater than the value of the refractive index n2, or the same as the value of the refractive index n2.

[0074] [Mathematical Expression 1]

[0075] 1≤n1 / n2≤1.15 (Equation 1)

[0076] Not limited to this, the value of refractive index n1 can also be less than the value of refractive index n2 if the difference between refractive index n1 and refractive index n2 is within 15% of refractive index n2.

[0077] The conditions in Equation 1 are calculated based on Snell's law to give the optical connector module 1 the desired high-precision optical characteristics. In this specification, "desired high-precision optical characteristics" includes, for example, the coupling efficiency, which is the coupling efficiency of light via the refractive index matching agent 30 between the optical transmission path 10 and the optical connector 20, and is a coupling efficiency higher than the specified value based on the required specification.

[0078] The refractive index matching agent 30 is positioned between the end face of the optical transmission path 10 and the first side surface A1 to adjust the refractive index of the optical path between the fiber core 121 and the first side surface A1. For example, the refractive index matching agent 30 is positioned between the end face of the optical waveguide 12 and the first lens 225. In this case, the second adhesive portion 223 of the optical connector 20 is bonded to the refractive index matching agent 30. Similarly, the end face of the optical transmission path 10 is bonded to the refractive index matching agent 30. The refractive index matching agent 30, while filling the interior of the first lens 225 and the first notch 222, is in close contact with the second adhesive portion 223 and the end face of the optical transmission path 10. As described above, the optical connector 20 is fixed to the optical transmission path 10 by the refractive index matching agent 30.

[0079] The optical connector 20 is optically coupled to the optical waveguide 12 included in the optical transmission path 10 when it is fixed to the optical transmission path 10. For example... Figure 6 As shown, the first side surface A1 faces the end face of the optical transmission path 10, such as the end face of the fiber core 121. Similarly, the first lens 225 faces the end face of the optical waveguide section 12, such as the end face of the fiber core 121. The refractive index matching agent 30 is located between the end faces of the first lens 225 and the fiber core 121.

[0080] like Figure 6As shown, the second lens 226 is positioned opposite the first lens 225 via the second base 22 of the optical connector 20. As an example, the second lens 226 is formed in a convex shape on its second side surface A2. The second lens 226 is formed as a convex lens on its second side surface A2. Along the direction of light propagation... Figure 6 In that cross-sectional view, the second lens 226 is formed in an arc shape. The half-width (radius) of the second lens 226 in the vertical direction is greater than the radius of the fiber core 121 of the optical transmission path 10.

[0081] In the second direction, which is orthogonal to the direction of light propagation and the first direction, the center P1 of the first lens 225 through which the optical axis passes coincides with the center P2 of the collective of multiple second lenses 226. The vertical position of the center P1 of the first lens 225 coincides with the vertical position of the center P2 of the second lens 226.

[0082] use Figure 6 As an example, the transmission pattern of light when it exits from the end face of the light transmission path 10 will be described. The light transmission path 10 will be described as transmitting light from the light-emitting element. However, it is not limited to this; the light transmission path 10 can also transmit light to the light-receiving element. In this case, it should be understood that the following description applies when the light propagation direction is set to be completely opposite.

[0083] When the refractive index matching agent 30 is made of a material having a refractive index approximately similar to that of the fiber core 121, Fresnel reflection of light incident on the boundary between the refractive index matching agent 30 and the fiber core 121 is suppressed by the matching of refractive indices. Therefore, light incident on this boundary is emitted into the interior of the refractive index matching agent 30 with high transmittance.

[0084] Light emitted from the fiber core 121 diffuses within the refractive index matching agent 30 due to diffraction and enters the first lens 225. When the optical connector 20 is formed of a material having a refractive index approximately similar to that of the refractive index matching agent 30, Fresnel reflection of light incident on the boundary between the optical connector 20 and the refractive index matching agent 30 is suppressed by the refractive index matching. Therefore, light incident on this boundary exits with high transmittance into the interior of the optical connector 20, for example, the second base 22.

[0085] As described later, when the first lens 225 is formed as a concave lens, the light emitted into the interior of the second base 22 is further diffused and enters the second lens 226. When the second lens 226 is formed as a convex lens, the light entering the boundary surface between the outside and the optical connector 20 is, for example, collimated by the second lens 226. In this way, the optical connector module 1, for example, propagates the light emitted from the optical transmission path 10 to the outside in a collimated state.

[0086] Light emitted from optical connector module 1 couples with other optical transmission paths. For example, light couples with the optical fiber held by the ferrule connected to optical connector 20. For example, light couples with optical waveguide paths mounted with other optical connectors connected to optical connector 20.

[0087] Figure 7 express Figure 1 The shape of the end face of the optical transmission path 10. For example... Figure 7 As shown, the end face of the optical waveguide 12 coincides with the end face of the substrate 11. The end faces of the fiber core 121 and the cladding 122 are formed on the same plane along the end face of the substrate 11. However, this is not a limitation; the end face of the optical waveguide 12, such as the end face of the fiber core 121, may also be a curved surface protruding toward the optical connector 20. For example, the end face of the fiber core 121 may be a curved surface that protrudes further toward the optical connector 20 than the end face of the cladding 122.

[0088] Figure 8 yes Figure 1 An enlarged sectional view along the arrow line VIII-VIII. Figure 8 In the optical transmission path 10, the region extends from the left-hand channel CH1 to the central channel CH2 located in the center in the left-right direction, among the multiple transmission channels included in the optical transmission path 10.

[0089] As an example, the first lens 225 is formed in a concave shape on the first side surface A1. The first lens 225 is formed as a concave lens on the first side surface A1. The first lens 225 is gently shaped into an arc along a first direction orthogonal to the direction of light propagation. The radius of curvature of the first lens 225 is sufficiently larger than the radius of curvature of the second lens 226.

[0090] The first lens 225 is formed to coincide with the plurality of second lenses 226 in a first direction orthogonal to the direction of light propagation. In the first direction orthogonal to the direction of light propagation, the center P1 of the first lens 225 through which the optical axis passes coincides with the center P2 of the plurality of second lenses 226 as a whole. The center P1 of the arc of the first lens 225 in the left-right direction coincides with the center P2 of the plurality of second lenses 226 in the left-right direction.

[0091] For example, the radius of curvature of the first lens 225 is in the range of 200 mm or more and 400 mm or less. For example, the radius of curvature of the first lens 225 may be 250 mm. For example, the radius of curvature of the second lens 226 is in the range of 0.2 mm or more and 0.5 mm or less.

[0092] For example, Figure 8The inter-plane distance L shown refers to the optical path length between the lens surface of the first lens 225 and the lens surface of the second lens 226. This inter-plane distance L varies depending on the position of the second lens 226 in the left-right direction. For example, the inter-plane distance L is in the range of 1.0 mm or more and 2.0 mm or less.

[0093] For example, Figure 8 The inter-channel spacing P, as indicated in the text, refers to the distance between the center of one second lens 226 in the left-right direction and the center of another second lens 226 adjacent to it in the left-right direction. Such an inter-channel spacing P is, for example, in the range of 0.125 mm or more and 0.250 mm or less. The inter-channel spacing P can be the same value relative to each of the multiple second lenses 226. The multiple second lenses 226 can be formed at equal intervals in the left-right direction. In this case, the multiple transmission channels of the optical transmission path 10 are also arranged at equal intervals in the left-right direction, and the left-right positions of the second lenses 226 are the same as or approximately the left-right positions of the corresponding transmission channels.

[0094] The parameters of the optical connector 20, including the radius of curvature of the first lens 225, the radius of curvature of the second lens 226, the inter-plane distance L, the inter-channel distance P, and the refractive index n1 of the optical connector 20, are determined and correlated with the core size and refractive index of the fiber core 121, the refractive index of the cladding 122, and the refractive index n2 of the refractive index matching agent 30, to obtain the desired high-precision optical characteristics.

[0095] For example, the parameters of the optical connector 20 are determined such that diffused light emitted from the fiber core 121 of the optical transmission path 10 passes through the refractive index matching agent 30 and enters the first lens 225, and exits as parallel light from the second lens 226 to the outside of the optical connector 20. Alternatively, the parameters of the optical connector 20 are determined such that parallel light entering the second lens 226 from the outside of the optical connector 20 passes through the first lens 225 and the refractive index matching agent 30, and is focused onto the fiber core 121 of the optical transmission path 10.

[0096] For example, the radius of curvature of the first lens 225 and the radius of curvature of the second lens 226 are determined based on the inter-plane distance L.

[0097] Figure 9A This means that in the absence of refractive index matching agent 30, in Figure 8 A schematic diagram of the shape of light propagating in the terminal channel CH1. Figure 9B This means that in the absence of refractive index matching agent 30, in Figure 8 A schematic diagram of the shape of light propagating in the central channel CH2.

[0098] exist Figure 9A as well as Figure 9BIn the scenario shown, unlike this disclosure, there is no refractive index matching agent 30 between the optical connector 20 and the optical transmission path 10, and the light propagates in the air. (The following uses...) Figure 10A as well as Figure 10B To describe the optical function of the refractive index matching agent 30, before that, as a comparison, the propagation of light in the absence of the refractive index matching agent 30 will be explained.

[0099] To emphasize the arc shape of the first lens 225 in the end channel CH1 for simpler explanation Figure 9A In the diagram, the left and right ends of the first lens 225 are schematically shown to be tilted as a large angle, like an inclined surface. However, in reality, the left and right ends of the first lens 225 form part of an arc with a gentle curvature in the left and right directions.

[0100] like Figure 9A as well as Figure 9B As shown, light with a beam diameter of φ enters from outside the optical connector 20 and enters the second lens 226 corresponding to each channel. The beam diameter φ is, for example, in the range of 75 μm or more and 100 μm or less.

[0101] At this time, for example, in the central channel CH2, light that enters the second lens 226 and passes through the interior of the optical connector 20 enters the lens surface of the first lens 225, which is approximately a plane along a first direction orthogonal to the direction of light propagation.

[0102] In the central channel CH2, light incident on the lens surface of the first lens 225 is refracted at an angle derived from the refractive index n1 of the optical connector 20 and the refractive index of air using Snell's law. For example, the refractive index of air is less than the refractive index n1 of the optical connector 20, and the lens surface of the first lens 225 is approximately planar. At this time, the light passing through the first lens 225 converges, and a portion of the light is focused onto the fiber core 121 of the light transmission path 10.

[0103] Similarly, for example, in the end channel CH1, light that enters the second lens 226 and passes through the interior of the optical connector 20 enters the lens surface of the first lens 225, which is approximately inclined at a predetermined angle along a first direction orthogonal to the direction of light propagation.

[0104] In the end channel CH1, light incident on the lens surface of the first lens 225 is refracted at an angle derived from the refractive index n1 of the optical connector 20 and the refractive index of air using Snell's law. For example, the refractive index of air is less than the refractive index n1 of the optical connector 20, and the lens surface of the first lens 225 is approximately a tilted surface. At this time, the light passing through the first lens 225 converges, but only a very small portion of the light couples with the fiber core 121 of the optical transmission path 10. The majority of the light illuminates a portion of the optical transmission path 10 that differs from the fiber core 121.

[0105] like Figure 9A as well as Figure 9B As shown, in the absence of the refractive index matching agent 30 and the absence of a large refractive index difference between the optical connector 20 and air, the refractive effect of the lens surface of the first lens 225 of the optical connector 20 increases. Furthermore, the first lens 225 is formed as an arc with a gentle curvature in the left-right direction, and the shape of its lens surface varies according to the left-right position of each channel. Therefore, the coupling efficiency of light emitted from the first lens 225 of the optical connector 20 to the light transmission path 10 is different for each channel.

[0106] The refractive index matching agent 30 disclosed herein suppresses or reduces the deviation in optical coupling efficiency between channels. Figure 10A In the presence of refractive index matching agent 30, and with Figure 9A The corresponding diagram. Figure 10B In the presence of refractive index matching agent 30, and with Figure 9B The corresponding diagram.

[0107] exist Figure 10A as well as Figure 10B In the situation shown, with Figure 9A as well as Figure 9B The situation shown is different; a refractive index matching agent 30 exists between the optical connector 20 and the optical transmission path 10, and light propagates within the refractive index matching agent 30. Using Figure 10A as well as Figure 10B This mainly explains the refractive index matching agent 30 of this disclosure relative to... Figure 9A and Figure 9B The validity of the situation.

[0108] like Figure 10A as well as Figure 10B As shown, light with a beam diameter of φ enters from outside the optical connector 20 and enters the second lens 226 corresponding to each channel. Figure 9A as well as Figure 9B Similarly, the beam diameter φ is, for example, in the range of 75 μm or more and 100 μm or less.

[0109] At this time, for example, in the central channel CH2, light that enters the second lens 226 and passes through the interior of the optical connector 20 enters the lens surface of the first lens 225, which is approximately a plane along a first direction orthogonal to the direction of light propagation.

[0110] Since the refractive index n1 of the optical connector 20 and the refractive index n2 of the refractive index matching agent 30 satisfy the relationship shown in Equation 1 and are approximately the same, the refraction effect of light incident on the lens surface of the first lens 225 in the central channel CH2 is suppressed. In the central channel CH2, the angular change caused by the refraction of light incident on the lens surface of the first lens 225 is suppressed. At this time, if the optical connector 20 is formed faithfully according to the parameters of the optical connector 20 determined to meet the desired high-precision optical characteristics, then the light can be effectively focused approximately as a whole onto the fiber core 121 of the light transmission path 10.

[0111] Similarly, for example, in the end channel CH1, light that enters the second lens 226 and passes through the interior of the optical connector 20 enters the lens surface of the first lens 225, which is approximately inclined at a predetermined angle along a first direction orthogonal to the direction of light propagation.

[0112] Since the refractive index n1 of the optical connector 20 and the refractive index n2 of the refractive index matching agent 30 satisfy the relationship shown in Equation 1 and are approximately the same as those in the center channel CH2, the refraction effect of light incident on the lens surface of the first lens 225 is suppressed, even in the end channel CH1. In the end channel CH1, the angular change caused by the refraction of light incident on the lens surface of the first lens 225 is suppressed. At this time, if the optical connector 20 is formed faithfully with the parameters of the optical connector 20 determined to meet the desired high-precision optical characteristics, the light can be effectively focused approximately as a whole onto the fiber core 121 of the light transmission path 10.

[0113] like Figure 10A as well as Figure 10B As shown, when the refractive index matching agent 30 is present and the refractive index difference between the optical connector 20 and the refractive index matching agent 30 is small, the refractive effect of the lens surface of the first lens 225 of the optical connector 20 is reduced. Therefore, even if the first lens 225 is formed as an arc with a gentle curvature in the left-right direction, and the shape of its lens surface varies according to the left-right position of each channel, the angular change caused by light refraction when light passes through the lens surface of the first lens 225 can be suppressed equally across the left-right direction. As a result, the coupling efficiency of the light emitted from the first lens 225 of the optical connector 20 to the light transmission path 10 is improved equally across the left-right direction.

[0114] For example, even if the shape of the first lens 225 is manufactured with deviations for each optical connector 20, the coupling efficiency of the light emitted from the first lens 225 to the optical transmission path 10 will be improved for each individual due to the presence of the refractive index matching agent 30.

[0115] According to the optical connector 20 of the above embodiment, even with a first lens 225 and a second lens 226, the desired high-precision optical characteristics can be easily obtained. For example, by making the number of first lenses 225 less than the number of second lenses 226, and different from the number of second lenses 226, it is not necessary to make a one-to-one correspondence between the first lenses 225 and the second lenses 226. It is not necessary to perform precise one-to-one alignment of the optical axes of the first lenses and the second lenses with each other as in the prior art.

[0116] Therefore, the degrees of freedom related to the optical design of the first lens 225 and the second lens 226 are increased. For example, the radius of curvature of the first lens 225 can be made larger than that of the second lens 226. Even if the optical design value of the second lens 226 is slightly off relative to the first lens 225 due to warping and shrinkage of the components of the optical connector 20 caused by thermal strain and other factors during manufacturing due to the properties of the materials constituting the optical connector 20, the desired optical design related to the first lens 225 and the second lens 226 can be easily achieved. As a result, the desired high-precision optical characteristics can be easily maintained for the optical connector module 1.

[0117] The optical connector 20, having a first lens 225 and a second lens 226, enables optical adjustment via a lens system that combines these lenses. The optical connector 20 increases the degree of freedom in optical adjustment through the two lenses. Therefore, the optical connector module 1 can easily provide emitted light with the desired beam state.

[0118] Since there is only one first lens 225, the formation positions of multiple second lenses 226 can be determined for only one first lens 225. This further increases the degree of freedom in the optical design related to the first lens 225 and the second lens 226, making it easier to maintain the desired high-precision optical characteristics for the optical connector module 1.

[0119] Furthermore, compared to the case where multiple first lenses 225 are formed on the first side surface A1, fine forming processing is not required, making the forming processing of the first lenses 225 on the first side surface A1 easier.

[0120] By forming a first lens 225 in the first side surface A1 as an arc with a gentle curvature in the left-right direction, the forming process is easier compared to forming the first side surface A1 as a completely flat surface without forming the first lens 225. For example, in the case of forming based on resin material, such as in the optical connector 20, warping and shrinkage of components are prone to occur during the manufacturing of the optical connector 20. Therefore, it is difficult to form an optically ideal flat surface on the first side surface A1. In this disclosure, by utilizing this warping and shrinkage of the component in the opposite way, a first lens 225 in the first side surface A1 with a gentle curvature in the left-right direction can be easily formed.

[0121] By arranging multiple second lenses 226 in a row in a first direction orthogonal to the light propagation direction, the optical connector 20 can also be optically coupled to the optical transmission path 10, which has multiple transmission channels arranged in a row in the same direction. Therefore, the optical connector module 1 can transmit multiple optical signals in parallel based on the multiple transmission channels formed across the optical transmission path 10 and the optical connector 20. This improves the transmission efficiency of the optical signals using the optical connector module 1.

[0122] By aligning the first lens 225 with the plurality of second lenses 226 in a first direction orthogonal to the direction of light propagation, the first lens 225 can optically act on the light passing through the plurality of second lenses 226. Thus, the lens system combining the first lens 225 and the second lenses 226 allows for optical adjustment of each of the plurality of transmission channels in the optical connector module 1. The optical connector module 1 can increase the degree of freedom in optical adjustment for each of the plurality of transmission channels through the two lenses. Therefore, the optical connector module 1 can easily provide emitted light with the desired beam state for each of the plurality of transmission channels.

[0123] By aligning the center P1 of the first lens 225, through which the optical axis passes, with the center P2 of the plurality of second lenses 226 as a whole, in a first direction orthogonal to the direction of light propagation and a second direction orthogonal to both the direction of light propagation and the first direction, the arc-shaped first lens 225 can be symmetrically arranged relative to the plurality of second lenses 226 in the vertical and horizontal directions. Therefore, in the plurality of transmission channels whose centers are located on the left and right sides respectively relative to the horizontal direction of the optical connector module 1, identical optical characteristics can be obtained. This improves the consistency of optical characteristics across the plurality of transmission channels of the optical connector module 1.

[0124] By making the radius of curvature of the first lens 225 larger than that of the second lens 226, the first lens 225 formed on the first side surface A1 does not require the same fine structure as the second lens 226 formed on the second side surface A2. Therefore, it is easier to form the first lens 225 on the first side surface A1.

[0125] By forming the first lens 225 as a concave lens, the optical connector 20 can force the diffusion of light emitted from the fiber core 121 of the light transmission path 10. For example, by forming a concave lens at a position opposite the fiber core 121 on the first side A1, the diffusion of light suppressed by the refractive index matching agent 30 can be forced in an earlier stage after emission. Conversely, light entering the first lens 225 from outside the optical connector 20 through the second lens 226 is focused and can be efficiently coupled to the fiber core 121.

[0126] By forming the second lens 226 as a convex lens, the optical connector 20 can, for example, convert light diffused by the first lens 225 (which is a concave lens) into collimated light. Through the combination of a concave lens and a convex lens formed by the first lens 225 and the second lens 226, the optical connector 20 can provide collimated light with a large aperture. Therefore, the optical connector 20 can provide collimated light that can be efficiently focused into a smaller spot. The optical connector 20 can illuminate collimated light with excellent characteristics.

[0127] The optical connector 20 can expand the allowable range of optical coupling by using collimated light with a large aperture. In other words, even if the optical axis is slightly offset from other optical transmission paths that are the objects of optical coupling, the optical connector 20 can still perform optical coupling within a specified allowable range.

[0128] By forming the second lens 226 as a convex lens, the optical connector 20 can focus the light entering the second lens 226 as collimated light. The optical connector 20 effectively focuses light through the combination of a concave lens and a convex lens formed by the first lens 225 and the second lens 226. Therefore, the optical connector 20 enables efficient coupling of light to the fiber core 121 of the optical transmission path 10.

[0129] By forming the optical connector 20 into an L-shape with the first base 21 and the second base 22, and with the first side A1 and the second side A2 formed on the second base 22 facing the end face of the optical transmission path 10, the first lens 225 and the second lens 226 can be compactly arranged at the far end of the L-shape. Therefore, even with the optical connector 20 miniaturized, the desired high-precision optical characteristics can be easily obtained.

[0130] The optical connector 20 is formed of resin material, so warping and shrinkage of the components are prone to occur during the manufacturing of the optical connector 20. Even under these circumstances, as described above, the desired optical design associated with the first lens 225 and the second lens 226 can be easily achieved. Thus, the desired high-precision optical characteristics can be easily maintained for the optical connector module 1.

[0131] The optical connector module 1, by having a refractive index matching agent 30 located between the end face of the optical transmission path 10 and the first side surface A1, can reduce the coupling loss between the optical transmission path 10 and the optical connector 20. For example, by placing the refractive index matching agent 30 between the end face of the optical waveguide 12 and the first lens 225, the optical connector module 1 can reduce losses caused by diffraction effects, losses caused by scattering or absorption of light due to foreign matter mixed into the first space S1 from the outside, and losses caused by Fresnel reflection, etc.

[0132] Specifically, by placing a refractive index matching agent 30 with a refractive index similar to that of the fiber core 121 in the optical path, the optical connector module 1 can suppress light diffusion caused by diffraction effects compared to the case in air. Thus, the optical connector module 1 can reduce the proportion of light in the light output from the fiber core 121 that is not coupled to the first lens 225 due to diffraction effects.

[0133] The refractive index matching agent 30 also serves to suppress the ingress of foreign matter. By filling the first space S1 with the refractive index matching agent 30, the optical connector module 1 can suppress the ingress of foreign matter from the outside. As a result, the optical connector module 1 can suppress the loss caused by scattering or absorption associated with foreign matter from the outside, thereby reducing coupling loss.

[0134] Since the refractive index of the refractive index matching agent 30 is approximately the same as that of the fiber core 121 and the optical connector 20, the optical connector module 1 can suppress Fresnel reflections at each boundary surface. The optical connector module 1 allows light to exit from the fiber core 121 with high transmittance, improving coupling efficiency. The optical connector module 1 also allows light to exit from the optical connector 20 with high transmittance, further improving coupling efficiency.

[0135] By fixing the optical transmission path 10 and the optical connector 20 with a refractive index matching agent 30, the optical connector module 1 can suppress optical axis misalignment caused by use and aging. Therefore, the optical connector module 1 can maintain the same optical characteristics over a long period of time, with its relative positions determined through initial positioning. In this way, the optical connector module 1 improves the quality of the product.

[0136] By making both the refractive index matching agent 30 and the optical connector 20 formed of a material having a refractive index similar to that of the fiber core 121, the optical connector module 1 is able to suppress Fresnel reflection and reduce coupling loss.

[0137] It will be apparent to those skilled in the art that this disclosure can be implemented in other specific ways besides the embodiments described above without departing from its spirit or essential characteristics. Therefore, the foregoing description is exemplary and not limiting. The scope of the disclosure is determined not by the foregoing description but by the appended claims. All modifications within their equivalents are included therein.

[0138] For example, the shape, arrangement, orientation, and number of the constituent parts described above are not limited to the content shown in the above description and the accompanying drawings. The shape, arrangement, orientation, and number of each constituent part can be arbitrarily configured as long as it can achieve its function.

[0139] For example, the values ​​of the parameters related to the optical transmission path 10, the optical connector 20, and the refractive index matching agent 30 are not limited to the values ​​mentioned above. Each parameter can include any value that enables the optical connector module 1 to obtain the desired high-precision optical characteristics.

[0140] In the above embodiments, the core size of the fiber core 121 of the optical transmission path 10 is described as being in the range of, for example, 5 μm or more and 15 μm or less, but it is not limited thereto. For example, the core size of the fiber core 121 may be 0.2 μm. For example, the refractive index of the fiber core 121 of the optical transmission path 10 may also be in the range of, for example, 3.0 or more and 4.0 or less. Similarly, the refractive index of the refractive index matching agent 30 may also be in the range of, for example, 3.0 or more and 4.0 or less. Similarly, the refractive index of the optical connector 20 may also be in the range of, for example, 3.0 or more and 4.0 or less.

[0141] In the above embodiments, it is stated that the difference between refractive index n1 and refractive index n2 is within 15% of refractive index n2, but it is not limited to this. For example, the difference between refractive index n1 and refractive index n2 can be within 20% or 25% of refractive index n2.

[0142] In the above embodiment, it is stated that the number of the first lens 225 is one, but it is not limited to this. The number of the first lens 225 can be two or more, as long as it is less than the number of the second lens 226.

[0143] Figure 11 This represents a modified example of optical connector module 1, and Figure 8 The corresponding enlarged sectional view. For example, such as... Figure 11As shown, the total number of second lenses 226 is 12, and the number of first lenses 225 can also be 6. In this case, for example, in the first direction orthogonal to the direction of light propagation, the center of one first lens 225 through which the optical axis passes and the centers of the two second lenses 226 corresponding to one first lens 225 can coincide. Furthermore, one first lens 225 can be formed such that it coincides with the two corresponding second lenses 226 in the first direction orthogonal to the direction of light propagation.

[0144] In the above embodiment, it is described that a plurality of second lenses 226 are arranged in a row in a first direction orthogonal to the direction of light propagation, but this is not a limitation. The second lenses 226 along the first direction orthogonal to the direction of light propagation may also be arranged in multiple rows in the vertical direction. In this case, relative to the multiple rows of second lenses 226, the first lens 225 may be formed as one or a row, or it may be adapted to the multiple rows of second lenses 226 to be formed in multiple rows in the vertical direction.

[0145] In the above embodiment, it is described that a plurality of second lenses 226 are formed at equal intervals in the left-right direction, but this is not a limitation. The plurality of second lenses 226 may also be formed at non-equal intervals in the left-right direction. In this case, the plurality of transmission channels of the optical transmission path 10 may also be arranged at non-equal intervals in the left-right direction.

[0146] In the above embodiment, it is described that the first lens 225 is formed to overlap with the entire plurality of second lenses 226 in a first direction orthogonal to the direction of light propagation, but it is not limited thereto. For example, the first lens 225 may also be formed to overlap with a portion of the plurality of second lenses 226 in a first direction orthogonal to the direction of light propagation.

[0147] In the above embodiment, it is described that in a first direction orthogonal to the direction of light propagation, the center P1 of the first lens 225 coincides with the center P2 of the plurality of second lenses 226 as a whole, but it is not limited to this. For example, the center P1 of the first lens 225 and the center P2 of the plurality of second lenses 226 as a whole may not coincide in the left-right direction.

[0148] In the above embodiment, it is described that in a second direction orthogonal to the direction of light propagation and the first direction, the center P1 of the first lens 225 coincides with the center P2 of the entire plurality of second lenses 226, but this is not a limitation. For example, the center P1 of the first lens 225 and the center P2 of the entire plurality of second lenses 226 may not coincide in the vertical direction.

[0149] In the above embodiments, it is stated that the radius of curvature of the first lens 225 is larger than that of the second lens 226, but this is not a limitation. For example, the radius of curvature of the first lens 225 may be the same as that of the second lens 226.

[0150] In the above embodiment, the first lens 225 is described as a concave lens, but it is not limited thereto. As long as the desired high-precision optical characteristics can be obtained, the first lens 225 can also be any type of lens such as a convex lens.

[0151] In the above embodiment, the second lens 226 is described as a convex lens, but it is not limited thereto. As long as the desired high-precision optical characteristics can be obtained, the second lens 226 can also be any type of lens such as a concave lens.

[0152] In the above embodiments, it is described that the shapes of the first lens 225 and the second lens 226 are arc-shaped in cross-sectional view, but they are not limited thereto. The shapes of the first lens 225 and the second lens 226 can be spherical or aspherical.

[0153] In the above embodiment, it is described that the optical waveguide portion 12 is formed on the upper surface of the substrate 11, but it is not limited thereto. For example, the optical waveguide portion 12 may also be embedded inside the substrate 11. In this case, the end face of the optical waveguide portion 12 may be formed to coincide with the end face of the substrate 11, and the end face of the fiber core 121 may be exposed from the substrate 11.

[0154] In the above embodiment, it is described that the refractive index matching agent 30 only fills the first space S1, but it is not limited to this. For example, the refractive index matching agent 30 may be filled in such a way that, in addition to the first space S1, it also fills the recess 212 of the optical connector 20 covering the optical transmission path 10.

[0155] In the above embodiment, it is described that the refractive index matching agent 30 is located between the end face of the optical waveguide 12 and the first lens 225, but it is not limited thereto. The refractive index matching agent 30 may also be located between the end face of the optical transmission path 10 and the first side surface A1, or in any other part other than between the end face of the optical waveguide 12 and the first lens 225. Even in such cases, the refractive index matching agent 30 serves to suppress the intrusion of foreign matter. Thus, the optical connector module 1 can suppress the loss caused by scattering or absorption due to foreign matter from the outside, as described above, thereby reducing coupling loss.

[0156] In the above embodiments, the optical connector module 1 is described as having an optical transmission path 10, which has a substrate 11 and an optical waveguide portion 12 stacked on the substrate 11, but is not limited thereto. The optical connector module 1 may also not have an optical transmission path 10, but only have an optical connector 20 and a refractive index matching agent 30.

[0157] Symbol Explanation

[0158] 1: Optical connector module;

[0159] 10: Optical transmission path;

[0160] 11: Matrix;

[0161] 12: Optical waveguide section;

[0162] 121: Fiber core;

[0163] 122: Cladding;

[0164] 122a: First cladding;

[0165] 122b: Second cladding;

[0166] 20: Optical connector;

[0167] 21: First base;

[0168] 211: Lower surface;

[0169] 212: concave part;

[0170] 213: Butt;

[0171] 213a: Abutment surface;

[0172] 214: First adhesive part;

[0173] 214a: Adhesive surface;

[0174] 215: Side wall;

[0175] 216: Avoid the concave part;

[0176] 217: Positioning section;

[0177] 22: Second base;

[0178] 221: Through hole;

[0179] 222: First incision site;

[0180] 223: Second adhesive part;

[0181] 224: Second incision site;

[0182] 225: Lens 1;

[0183] 226: Second lens;

[0184] 30: Refractive index matching agent;

[0185] A: Ingredients;

[0186] A1: First side view;

[0187] A2: Second side view;

[0188] C: Corner;

[0189] CH1: Terminal channel;

[0190] CH2: Central channel;

[0191] F: Embedded border;

[0192] L: Inter-face distance;

[0193] P: Spacing between channels;

[0194] P1: Center;

[0195] P2: Center;

[0196] S1: First Space;

[0197] S2: Second Space;

[0198] n1: Refractive index;

[0199] n2: Refractive index;

[0200] φ: Beam diameter.

Claims

1. An optical connector, mounted to an optical transmission path having a substrate, an optical waveguide portion stacked on the substrate, and multiple transmission channels, the optical connector comprising: The first side face is opposite to the end face of the optical transmission path; The second side is located on the opposite side of the first side in the direction of light propagation; At least one first lens is formed on the first side surface and faces the end face of the optical waveguide portion; A plurality of second lenses are formed in the second side surface at a position opposite to the first lens in the propagation direction; The number of the first lens is less than the number of the second lens; The shape of the lens surface of the first lens varies according to the lateral position of each of the multiple transmission channels for each channel.

2. The optical connector according to claim 1, wherein the number of the first lens is one.

3. The optical connector according to claim 2, wherein a plurality of the second lenses are arranged in a row in a first direction orthogonal to the propagation direction.

4. The optical connector according to claim 2 or 3, wherein the first lens is formed to be integrally overlapped with the plurality of the second lenses in a first direction orthogonal to the propagation direction.

5. The optical connector according to claim 2 or 3, wherein in a first direction orthogonal to the propagation direction and a second direction orthogonal to both the propagation direction and the first direction, the center of the first lens through which the optical axis passes coincides with the center of the plurality of second lenses as a whole.

6. The optical connector according to any one of claims 1 to 3, wherein the radius of curvature of the at least one first lens is larger than the radius of curvature of each of the plurality of second lenses.

7. The optical connector according to any one of claims 1 to 3, wherein the at least one first lens is a concave lens.

8. The optical connector according to any one of claims 1 to 3, wherein each of the plurality of second lenses is a convex lens.

9. The optical connector according to any one of claims 1 to 3, the optical connector comprising: a first base portion disposed on the optical transmission path; and a second base portion extending from the first base portion in a direction orthogonal to the extending direction of the first base portion and facing an end face of the optical transmission path; The first side and the second side are formed on the second base.

10. The optical connector according to any one of claims 1 to 3, wherein the optical connector is formed of a resin material.

11. Optical connector module, equipped with: The optical connector according to any one of claims 1 to 3; The optical transmission path includes the substrate and the optical waveguide portion stacked on the substrate; A refractive index matching agent is positioned between the end face of the light transmission path and the first side face to adjust the refractive index.

12. The optical connector module according to claim 11, wherein the refractive index matching agent is located between the end face of the optical waveguide and the at least one first lens.

Images