JP5307040B2 - Bent optical waveguide structure, optical transceiver module, and optical connector module - Google Patents

Description

  The present invention relates to a bent optical waveguide structure that optically couples an optical element and a transmission medium arranged in an orthogonal direction, or optically couples transmission media arranged in an orthogonal direction, and the bent optical waveguide structure. The present invention relates to an optical transmission / reception module and an optical connector module.

  Japanese Patent Application Laid-Open No. 2004-151561 discloses a technique regarding an optical transceiver module. More specifically, the optical transceiver module 1 includes a bent optical waveguide structure 4 for optically coupling the optical element 2 and the optical fiber 3 arranged in the orthogonal direction. Yes. In the optical transceiver module 1, the optical element 2 is mounted on a substrate 5. The optical fiber 3 is provided as a transmission medium and is arranged in parallel to the substrate 5. The optical fiber 3 can be optically coupled to the optical element 2 whose optical axis is perpendicular to the substrate 5 because the bent optical waveguide structure 4 is interposed between the optical fiber 3 and the optical element 2. Yes.

  The bent optical waveguide structure 4 has a bent core portion 6, an upper clad portion 7 and a lower clad portion 8, and is formed in a rectangular cross section. The bent optical waveguide structure 4 has an optical element facing surface 9 and an optical fiber facing surface 10, and one end face 11 of the core portion 6 is exposed on the optical element facing surface 9. ing. The end face 11 is disposed so as to face the optical element 2 at a predetermined interval. On the optical fiber facing surface 10, the other end surface 12 of the core portion 6 is exposed flush. The end face 12 is disposed so as to face the core 13 of the optical fiber 3 at a predetermined interval.

  The manufacturing method of the bent optical waveguide structure 4 will be described with reference to FIGS. 9B to 9G. First, as shown in FIGS. 9B and 9C, the upper cladding portion 7 and the lower cladding portion. 8 is molded. Although not particularly illustrated, the upper clad portion 7 is molded by using a dedicated molding die, and the lower clad portion 8 is molded by using a dedicated mold. Both the upper clad part 7 and the lower clad part 8 have arcuate surfaces 14 and 15, and are formed so that the cross-sectional shape becomes the above-mentioned rectangular shape when the arcuate surfaces 14 and 15 that are uneven are overlapped. ing.

  Explaining the shape in more detail, the lower clad portion 8 is formed in a quarter cylindrical shape. Further, the upper clad portion 7 is formed in a shape obtained by removing the ¼ cylindrical lower clad portion 8 from the quadrangular prism. A groove 16 extending in the arc direction of the arc surface 14 is formed on the arc surface 14 of the upper cladding portion 7. The groove 16 is formed so that both end portions of the groove open to the optical element facing surface 9 and the optical fiber facing surface 10.

  After forming the upper clad part 7 and the lower clad part 8, respectively, next, as shown in FIGS. 9D and 9E, the groove 16 is filled with a molten resin (core resin) to be the core part 6. Finally, as shown in FIGS. 9F and 9G, when the upper cladding portion 7 and the lower cladding portion 8 are bonded together so that the circular arc surfaces 14 and 15 are overlapped, the bending optical waveguide structure 4 Manufacturing is complete. In the bent optical waveguide structure 4 after the manufacture is completed, the periphery of the core portion 6 is covered with the upper clad portion 7 and the lower clad portion 8.

JP 2005-115346 A

  By the way, in the said prior art, manufacture of the bending optical waveguide structure 4 requires the following 4 processes. That is, a molding step of the upper cladding portion 7, a molding step of the lower cladding portion 8, a step of filling the core resin in the groove 16 of the upper cladding portion 7, and a step of bonding the lower cladding portion 8 to the upper cladding portion 7. 4 steps are required. Therefore, there is a problem that the cost increases due to the large number of processes. Moreover, since there are many processes, the productivity of the bent optical waveguide structure 4 is lowered.

  In addition, in the above prior art, when the core resin is filled in the groove 16 of the upper clad portion 7, a dispenser is used, but filling it so that bubbles are not mixed is a troublesome operation. Has problems (leads to reduced productivity). In addition, there is a problem that it is difficult to precisely control the amount of core resin to be filled with a dispenser (which leads to a decrease in productivity). Further, since the grooves 16 extend in the arc direction, there is a problem that uniform filling of the core resin is difficult (leading to a decrease in productivity). When a large amount of the core resin is filled, excess portions protrude when the lower clad portion 8 is bonded, and a gap is generated in the upper clad portion 7 and the lower clad portion 8 due to the protrusion. Therefore, there is a problem that there is a risk of light loss. Further, there is a problem that it is a troublesome work to bond the upper clad part 7 and the lower clad part 8 so as not to mix bubbles.

  This invention is made | formed in view of an above-described situation, and makes it a subject to provide the bending optical waveguide structure which can aim at cost reduction and productivity improvement. It is another object of the present invention to provide an optical transceiver module and an optical connector module that include the bent optical waveguide structure.

  The bent optical waveguide structure of the present invention according to claim 1, which has been made to solve the above-mentioned problems, is a light-transmitting block portion having an arc surface, and projects from the arc surface integrally with the arc surface and of the same material. And an optical waveguide having a convex cross section extending in the arc direction, and the outer surface of the optical waveguide extending in the arc direction is formed in a mirror state.

  According to the present invention having such characteristics, the bent optical waveguide structure is a single component and can be optically coupled with a single material. The light (light beam) incident from the incident surface in the optical waveguide portion travels to the emission surface while being reflected by the upper surface (outer surface) of the optical waveguide portion serving as an interface with air. The light travels while bending in the arc direction according to the shape of the optical waveguide. The light reflected from the upper surface of the optical waveguide section is bent in the direction of the arc, so that part of the light passes through the block section, but returns to the optical waveguide section and is reflected again. Proceed while repeating.

  A bent optical waveguide structure according to a second aspect of the present invention is the bent optical waveguide structure according to the first aspect, wherein a convex lens is integrally provided at one end surface position and / or the other end surface position of the optical waveguide portion. It is characterized by that.

  According to the present invention having such characteristics, even if the NA of light traveling toward the incident surface in the optical waveguide section (incident light NA) is large, the incident light NA becomes small due to the presence of the convex lens.

  An optical transmission / reception module according to a third aspect of the present invention, which has been made to solve the above problems, comprises the bent optical waveguide structure according to the first or second aspect, an optical element, and a transmission medium. The optical element is arranged to face one end face of the optical waveguide section in the bent optical waveguide structure, and the transmission medium is arranged to face the other end face of the optical waveguide section. It is characterized by.

  According to the present invention having such a feature, when the optical element is a light emitting element, light (light ray) from the light emitting element is incident on the incident surface of the optical waveguide portion in the bent optical waveguide structure and then interfaced with air. It progresses to the output surface while being reflected by the upper surface (outer surface) of the optical waveguide part. The light travels while bending in the arc direction according to the shape of the optical waveguide. The light (light beam) emitted from the emission surface of the optical waveguide part enters the transmission medium, and thereby the light emitting element and the transmission medium are optically coupled. On the other hand, when the optical element is a light receiving element, the light (light beam) emitted from the transmission medium is incident on the incident surface of the optical waveguide unit in the bent optical waveguide structure, and then the optical waveguide unit serving as an interface with air. The light travels toward the exit surface while being reflected by the upper surface (outer surface). The light emitted from the emission surface enters the light receiving element, whereby the light receiving element and the transmission medium are optically coupled.

  An optical connector module of the present invention according to claim 4, which has been made to solve the above problem, comprises the bent optical waveguide structure according to claim 1 or 2 and a pair of transmission media, One of the transmission media is arranged to face one end face of the optical waveguide section in the bent optical waveguide structure, and the other of the transmission medium is arranged to face the other end face of the optical waveguide section. It is characterized by becoming.

  According to the present invention having such characteristics, light (light rays) emitted from one transmission medium is incident on the incident surface of the optical waveguide portion in the bent optical waveguide structure, and thereafter becomes an interface with air. The light travels toward the exit surface while being reflected by the upper surface (outer surface) of the optical waveguide. The light (light beam) emitted from the emission surface is incident on the other transmission medium, whereby the pair of transmission media are optically coupled.

  Here, features other than the above will be described below.

  (1) The molding die of the present invention includes a concave block portion molding portion having an arc surface, and a groove-shaped optical waveguide molding portion that dents the arc surface and extends in the arc direction, and The concave shape of the block portion molding portion is formed into a concave shape that is one of a plurality of cylinders divided in the axial direction, and the groove inner surface of the optical waveguide portion molding portion is further mirror-finished And

  According to the present invention having such characteristics, it is possible to provide a molding die suitable for manufacturing a bent optical waveguide structure.

  (2) The method for producing a bent optical waveguide structure according to the present invention uses the molding die described in (1) above, and transmits light to the block molding portion and the optical waveguide molding portion of the molding die. A bent optical waveguide structure is manufactured by filling the resin material and taking out the molded product after cooling.

  According to the present invention having such characteristics, a bent optical waveguide structure for optically coupling an optical element and a transmission medium or a pair of transmission media by using the molding die described in (1). Can be manufactured by a single resin molding.

  According to the first aspect of the present invention, since the bent optical waveguide structure can be optically coupled with one part and one material, the structure and manufacturing can be simplified as compared with the conventional one. As a result, the cost can be reduced. In addition, the productivity can be improved as compared with the conventional case.

  According to the second aspect of the present invention, there is an effect that the incident light NA can be reduced by the convex lens. Thereby, there is an effect that light loss can be reduced. In addition, according to the present invention, the convex lens can increase the positional displacement tolerance between the optical element and the bent optical waveguide structure and the transmission medium and the bent optical waveguide structure, thereby increasing the effectiveness on the mounting surface. Play.

  According to the third aspect of the present invention, it is possible to provide an optical transceiver module that is low in cost and high in productivity.

  According to the fourth aspect of the present invention, there is an effect that it is possible to provide a low-cost and high-productivity optical connector module.

(A) is a schematic side view of an optical transceiver module including the bent optical waveguide structure of the present invention, and (b) is a schematic side view of an optical connector module including the bent optical waveguide structure of the present invention. (A) is a perspective view of the bending optical waveguide structure of this invention, (b) is the sectional view on the AA line of (a). It is sectional drawing of a shaping die. It is a figure which shows a mode that the advancing direction of an incident ray bends at right angle. It is a graph which shows the relationship between the bending radius of a bending optical waveguide structure, and optical loss. It is a figure which shows the mode of the light leakage in a bending optical waveguide structure. It is a graph which shows the relationship between incident light NA and optical loss. It is a perspective view of the bending optical waveguide structure which has a lens. (A) is a sectional view of a conventional optical transceiver module, (b), (d), (f) are sectional views relating to the production of a bent optical waveguide structure, (c), (e), (g) are It is a front view which concerns on manufacture of a bending optical waveguide structure.

  The bent optical waveguide structure is for optically coupling an optical element and a transmission medium, or for optically coupling a pair of transmission media, and is one of a plurality of cylinders divided in the axial direction. A light-transmitting block portion formed in such a shape, and an optical waveguide portion having a convex cross section extending in the arc direction that is integral with the arc surface of the block portion and protrudes from the arc surface with the same material, The outer surface of the optical waveguide portion extending in the arc direction is formed in a mirror state.

  Embodiment 1 will be described below with reference to the drawings. FIG. 1A is a schematic side view of an optical transceiver module including the bent optical waveguide structure of the present invention. 2A is a perspective view of the bent optical waveguide structure of the present invention, and FIG. 2B is a cross-sectional view taken along line AA of FIG. FIG. 3 is a cross-sectional view of the molding die.

  In FIG. 1A, reference numeral 21 indicates the optical transceiver module of the present invention. The optical transceiver module 21 includes a light emitting and receiving unit 22, an optical fiber 23 as an example of a transmission medium, and the bent optical waveguide structure 24 of the present invention. The optical transmission / reception module 21 is configured such that, in the optical transmission / reception unit 25, the light emitting / receiving unit 22 and the optical fiber 23 arranged in the orthogonal direction can be optically coupled by the bent optical waveguide structure 24. First, the above configuration will be described.

  The light emitting / receiving unit 22 is mounted on a substrate (not shown) in the optical transmission / reception unit 25 and includes a light emitting element such as a surface light emitting element (VCSEL) and / or a light receiving element such as a photodiode. The light emitting / receiving unit 22 is arranged so that the optical axis of the light emitting element and / or the light receiving element is orthogonal to the mounting surface of the substrate (not shown). When the optical element included in the light receiving / emitting unit 22 is one of the light emitting element and the light receiving element, one optical waveguide unit 29 described later in the bent optical waveguide structure 24 is provided, One optical fiber 23 is also provided. On the other hand, when both the light emitting element and the light receiving element are included, two optical waveguide portions 29 are provided in accordance with the arrangement of these optical elements, and two optical fibers 23 are also provided. The light emitting / receiving unit 22 is disposed so as to face one end surface 33 of an optical waveguide unit 29 described later while aligning the optical axes of the optical elements. In this embodiment, the case where a light emitting element is included will be described as an example.

  As the optical fiber 23, a known transmission medium as described above is used. The optical fiber 23 includes a core 26, a clad 27 provided outside the core 26, and a coating (not shown) provided outside the clad 27. The optical fiber 23 is arranged so that one end side thereof is fixed in the optical transmitting / receiving unit 25 and the end face on one end side is opposed to the other end face 34 of the optical waveguide part 29 described later of the bent optical waveguide structure 24. .

  The bent optical waveguide structure 24 is a transparent material for optically coupling the optical element and the optical fiber 23, and is a single component and manufactured from one material. The bent optical waveguide structure 24 is not a combination of a plurality of components, but is manufactured by a single resin molding. The bent optical waveguide structure 24 is fixed by appropriate means in the optical transmitting / receiving unit 25 (it is not particularly limited as long as it is a fixing means that does not affect optical coupling).

  In FIG. 1A and FIG. 2, the bent optical waveguide structure 24 has a block portion 28 and an optical waveguide portion 29. In the present embodiment, the block portion 28 is formed in a shape (1/4 cylindrical shape) that becomes one of four cylinders divided in the axial direction. Since the block part 28 is such a shape, it has the circular arc surface 30, the two rectangular end surfaces 31, and the two fan-shaped end surfaces 32. FIG. The two rectangular end faces 31 are arranged at a right angle.

  The optical waveguide portion 29 is formed so as to be a portion having a convex cross section that protrudes from the arc surface 30 and extends in the arc direction. The optical waveguide portion 29 is a core portion that is a substantially ridge that bends along the arcuate surface 30, and is disposed and formed at the center in the width direction of the arcuate surface 30 in this embodiment. The optical waveguide section 29 has one end face 33 flush with the horizontal rectangular end face 31 in the figure and the other end face 34 flush with the vertical rectangular end face 31 in the figure. Is formed.

  One end surface 33 is disposed so as to face the optical element of the light emitting / receiving unit 22 (arranged according to the mounting position of the light emitting / receiving unit 22). The other end face 34 is disposed so as to face the core 26 of the optical fiber 23 (arranged in accordance with a fixing position for fixing one end side of the optical fiber 23).

  The optical waveguide 29 has at least an outer surface (upper surface 35, side surface 36) extending in the arc direction in a mirror state. The outer surface (upper surface 35, side surface 36) is formed as a portion that becomes an interface with air. The reason why the mirror surface is formed is to suppress light scattering at the interface.

  The bent optical waveguide structure 24 as described above is resin-molded using a molding die 37 as shown in FIG. 3, for example.

  In FIG. 3, a molding die 37 includes an upper die 38 and a lower die 39 as the main components. The upper mold 38 is formed with a concave block portion molding portion 41 having an arc surface 40 and a groove-shaped optical waveguide molding portion 42 which is recessed in the arc surface 40 and extends in the arc direction. The bent optical waveguide structure 24 (see FIG. 2) is manufactured by a molding method that transfers the shapes of the block portion molding portion 41 and the optical waveguide portion molding portion.

  The block portion forming portion 41 is a portion for forming the block portion 28 (see FIG. 2) in the bent optical waveguide structure 24, and the optical waveguide portion forming portion 42 is an optical waveguide portion 29 (in the bent optical waveguide structure 24). 2) is formed as a part to be molded. The split portions of the upper mold 38 and the lower mold 39 are set in accordance with the position of the rectangular end face 31 (see FIG. 2) in the bent optical waveguide structure 24. Note that the illustration of the gate for filling the transparent resin material is omitted.

  The molding die 37 is formed by subjecting at least the surface of the optical waveguide molding portion 42 to mirror finishing. By performing the mirror surface processing, the outer surface of the molded optical waveguide portion 29 (see FIG. 2) is formed in a mirror surface state.

  When the molding die 37 as described above is used and the block portion molding portion 41 and the optical waveguide portion molding portion 42 of the molding die 37 are filled with a light-transmitting resin material and the molded product is taken out after cooling, FIG. A bent optical waveguide structure 24 as shown in FIG. 2 is formed.

  Next, the bent optical waveguide structure 24 will be described more specifically with reference to FIGS. 2 and 4 to 7.

  FIG. 4 is a diagram showing how the traveling direction of the incident light beam is bent at a right angle, FIG. 5 is a graph showing the relationship between the bending radius of the bent optical waveguide structure and the optical loss, and FIG. 6 is the light leakage of the bent optical waveguide structure. FIG. 7 is a graph showing the relationship between incident light NA and optical loss. In addition, the numerical value given in the following description shall be an example.

  In FIG. 2, the bent optical waveguide structure 24 is formed so that the bending radius is 5 mm. That is, the length (radius shown by the dimension B) of the rectangular end surface 31 in the longitudinal direction is 5.0 mm. The optical waveguide 29 has a square cross section and is formed so that the length of one side C is 0.2 mm. The bent optical waveguide structure 24 is molded using a thermoplastic resin having transparency (light transmission), and the refractive index of the thermoplastic resin is n = 1.52. Examples of the thermoplastic resin include polymethyl methacrylate resin (PMMA), polycarbonate resin (PC), cycloolefin resin (COP), and the like. These thermoplastic resins are suitable. To do.

  In FIG. 4, the optical loss of the bent optical waveguide structure 24 as described above is calculated by ray tracing simulation. The simulation conditions are as follows: (1) the emission diameter of the light source is φ0.15 mm, and (2) the numerical aperture (NA) of the light emitted from the light source (incident light to the optical waveguide section 29) is NA = 0. (NA here represents the sine value of the angle θ at which the maximum value of the light intensity is 5% in the angular intensity distribution of the light emitted from the light source. NA = sin θ), and (3) the light receiving diameter of the light receiver is φ0. 3 mm, and (4) the number of rays is 100,000. In order to make a comparison with the conventional example, the bent optical waveguide structure 4 shown in FIG. 9 is manufactured so that the refractive index difference Δn between the lower clad part 8 and the core part 6 becomes 0.1. I made it. Also, the bending radius was set to 5 mm.

  According to the ray tracing simulation, the calculation result that the optical loss of the bent optical waveguide structure 24 is 0.03 dB is obtained, and the optical loss of the bent optical waveguide structure 4 of the conventional example is 0.01 dB. The calculation result was obtained. Both of the calculation results are very small values of 0.1 dB or less, and based on the calculation results, it can be seen that the bent optical waveguide structure 24 has no practical problem.

  According to the ray tracing simulation, it can be seen that the traveling direction of the incident ray is bent at right angles before and after the bent optical waveguide structure 24 as shown in FIG. Specifically, the light (light beam) incident from the incident surface (one end surface 33) in the optical waveguide unit 29 is reflected by the upper surface 35 (outer surface) of the optical waveguide unit serving as an interface with air, and the output surface (the other surface). To the end face 34). The light travels while bending in the arc direction according to the shape of the optical waveguide portion 29. The light reflected by the upper surface 35 of the optical waveguide section 29 is partially bent through the block portion 28 because the shape of the optical waveguide section 29 is bent in the arc direction, but again to the optical waveguide section 29. Go back and repeat the reflection.

  The graph of FIG. 5 shows the relationship between the bending radius of the bent optical waveguide structure 24 and the optical loss. In this graph, the bending radius of the bending optical waveguide structure 24 is changed with the size of the optical waveguide portion 29 (see FIG. 2) (a square whose cross-sectional shape is 0.2 mm on one side) being constant, and a ray tracing simulation is performed. The optical loss is calculated, and the simulation conditions are the same as described above. FIG. 5 shows that the optical loss increases as the bending radius of the bent optical waveguide structure 24 increases.

  FIG. 6 shows how light leaks in the optical waveguide portion 29 ′ of the bent optical waveguide structure 24 ′. Here, the bent optical waveguide structure 24 'has a bending radius of 15 mm instead of 5 mm. Referring to FIG. 6, it can be seen that the number of light rays leaking from the optical waveguide portion 29 'to the block portion 28' of the bent optical waveguide structure 24 'is very large. Therefore, it can be seen that the optical loss increases when the bending radius increases, such as the bent optical waveguide structure 24 '.

  What can be said from the above is that the bending radius should be reduced in order to reduce the light leaking from the optical waveguide section 29 (optical waveguide section 29 ') to the block section 28 (block section 28'). Judging from FIG. 5, it can be said that the bending radius should be 7 mm or less in order to reduce the optical loss to 0.1 dB or less.

  When the bending radius is reduced, the dimensions of the bent optical waveguide structure 24 are reduced accordingly. As a result, the optical transceiver module 21 shown in FIG. Therefore, by using the bent optical waveguide structure 24, the optical transceiver module 21 can be designed to be small.

  The graph of FIG. 7 shows the relationship between the incident light NA and the optical loss of the bent optical waveguide structure 24 with a bending radius of 5 mm. The graph here shows the light loss calculated by ray tracing simulation while changing the incident light NA to the bent optical waveguide structure 24, and the simulation conditions are the same as above except for the light source emission light NA. To do. FIG. 7 shows that the optical loss increases as the incident light NA increases. Further, for example, it is understood that the light loss becomes larger than 0.1 dB when the incident light NA becomes larger than 0.3. Therefore, it can be seen that the incident light NA needs to be reduced in order to reduce the optical loss in the bent optical waveguide structure 24.

  As described above, according to the present invention, the bent optical waveguide structure 24 is a single component and can be optically coupled with one material, and therefore, compared with the conventional bent optical waveguide structure 4 (see FIG. 9). The structure and manufacturing can be simplified, and the cost can be reduced. In addition, the productivity can be improved as compared with the conventional case.

  In addition, according to the present invention, the bent optical waveguide structure 24 is made of one part and one material, and is molded and manufactured using the molding die 37. Therefore, it is troublesome to fill the core resin so that bubbles are not mixed. As a result, there is an effect that productivity can be improved as compared with the conventional bent optical waveguide structure 4 (see FIG. 9).

  Further, according to the present invention, since the bent optical waveguide structure 24 is molded and manufactured using the molding die 37, it is not necessary to use a dispenser, and the amount of core resin to be filled is precisely determined by the dispenser. As a result, it is possible to improve the productivity as compared with the conventional bent optical waveguide structure 4 (see FIG. 9).

  In addition, according to the present invention, there is no structure and manufacturing in which the surplus of the core resin protrudes, so that there is an effect that no gap that leads to optical loss is generated.

  In addition, the optical transmission / reception module 21 has the effect that the bent optical waveguide structure 24 has the above-described effects, and thus can provide the optical transmission / reception module 21 with low cost and high productivity.

  Embodiment 2 will be described below with reference to the drawings. FIG. 1B is a schematic side view of an optical connector module including the bent optical waveguide structure of the present invention. In addition, the same code | symbol is attached | subjected to the same component as the said Example 1, and detailed description is abbreviate | omitted.

  In FIG. 1B, reference numeral 51 indicates the optical connector module of the present invention. The optical connector module 51 includes a pair of optical fibers 23 as an example of a transmission medium and the bent optical waveguide structure 24 of the present invention. The optical connector module 51 is configured such that a pair of optical fibers 23 arranged in an orthogonal direction can be optically coupled by the bent optical waveguide structure 24 in the optical connector portion 52.

  One end of each of the pair of optical fibers 23 is fixed to the optical connector 52 by appropriate means. Note that examples of transmission media other than the optical fiber 23 include known optical waveguides.

  In the above configuration, it can be seen that it is effective to apply the optical connector module 51 to a location where the medium (the optical fiber 23) is to be bent to a small diameter on the transmission medium. The optical connector module 51 includes the bent optical waveguide structure 24 in this configuration, and the effects related to the bent optical waveguide structure 24 are the same as those in the first embodiment.

  In this embodiment, the bent optical waveguide structure 24 can be said to be applied to an optical coupling portion of an optical connector that optically couples a pair of optical fibers 23 at a right angle.

  The light (light beam) emitted from one optical fiber 23 is incident on the incident surface (one end surface 33) of the optical waveguide unit 29 in the bent optical waveguide structure 24, and then the optical waveguide unit that becomes an interface with air. The light travels toward the light exit surface (the other end surface 34) while being reflected by the upper surface 35 (outer surface). The light (light beam) emitted from the emission surface is incident on the other optical fiber 23, whereby the pair of optical fibers 23 are optically coupled.

  Embodiment 3 will be described below with reference to the drawings. FIG. 8 is a perspective view of a bent optical waveguide structure having a lens. In addition, the same code | symbol is attached | subjected to the same structural member as the said Examples 1, 2, and detailed description is abbreviate | omitted.

  In FIG. 8, reference numeral 61 indicates the bent optical waveguide structure of the present invention. The bent optical waveguide structure 61 is used in place of the bent optical waveguide structure 24 of the optical transceiver module 21 shown in FIG. 1A or the bent optical waveguide structure 24 of the optical connector module 51 shown in FIG. Therefore, it is possible to increase the allowable amount of positional deviation with respect to the surface optical element and the transmission medium. This will be specifically described below.

  The bent optical waveguide structure 61 is a single component and is manufactured from a single material. The bent optical waveguide structure 61 is manufactured not by combining a plurality of parts but by a single resin molding. The bent optical waveguide structure 61 includes a block portion 62, a pair of optical waveguide portions 63, and a convex lens 64 provided integrally at the end surface position of each optical waveguide portion 63.

  The block part 62 is formed in a shape that is one of four cylinders divided in the axial direction. The block portion 62 having such a shape has an arc surface 65, two rectangular end surfaces 66, and two fan-shaped end surfaces 67. In addition, the block portion 62 has two recesses 68. The two rectangular end faces 31 are arranged at a right angle. The two recesses 68 are respectively formed so as to dent the arc surface 65. Further, the two concave portions 68 are arranged and formed in accordance with the positions of the convex lenses 64. The two concave portions 68 are formed so as to be concave according to the radius of each convex lens 64. In the case where the two concave portions 68 are not formed, the convex lens 64 may be formed on each rectangular end surface 66.

  The pair of optical waveguide portions 63 are both the same, and are divided for transmission and reception. Each optical waveguide 63 is formed so as to have a convex section extending from the arc surface 65 and extending in the arc direction. Each of the optical waveguide portions 63 is a core portion that is a substantially ridge that bends along the circular arc surface 65, and is arranged and formed on the circular arc surface 65 at a predetermined interval in this embodiment.

  Each optical waveguide portion 63 has at least an outer surface (upper surface 69, side surface 70) extending in the arc direction in a mirror state. The outer surface (upper surface 69, side surface 70) is a portion that becomes an interface with air.

  Each convex lens 64 has an effect that the incident light NA to each optical waveguide 63 can be reduced when the incident light NA increases. Thereby, there is an effect that light loss can be reduced. In addition, each convex lens 64 has an effect that it is possible to increase the positional displacement tolerance with respect to the surface optical element and the transmission medium as described above. According to the present invention, it can be seen that each convex lens 64 is very effective on the mounting surface. Note that the convex lens 64 may be integrally disposed at both end surface positions of the optical waveguide portion 63.

  In addition, the present invention can of course be modified in various ways within the scope not changing the gist of the present invention.

21 ... Optical transceiver module 22 ... Light emitting / receiving unit 23 ... Optical fiber (transmission medium)
DESCRIPTION OF SYMBOLS 24 ... Bending optical waveguide structure 25 ... Optical transmission / reception part 26 ... Core 27 ... Cladding 28 ... Block part 29 ... Optical waveguide part 30 ... Arc surface 31 ... Rectangular end surface 32 ... Fan-shaped end surface 33 ... One end surface 34 ... Other end surface 35 ... Upper surface (outer surface)
36 ... Side (outside)
37 ... Molding die 38 ... Upper die 39 ... Lower die 40 ... Arc surface 41 ... Block portion forming portion 42 ... Optical waveguide portion forming portion 51 ... Optical connector module 52 ... Optical connector portion 61 ... Bending optical waveguide structure 62 ... Block Part 63: Optical waveguide part 64 ... Convex lens 65 ... Arc surface 66 ... Rectangular end face 67 ... Fan-shaped end face 68 ... Concave part 69 ... Upper surface (outer surface)
70 ... Side (outside)

Claims (4)

A light-transmitting block portion having an arc surface, and an optical waveguide portion having a convex cross section that is integral with the arc surface and is made of the same material and protrudes from the arc surface and extends in the arc direction. A bent optical waveguide structure characterized in that an outer surface extending in an arc direction is formed in a mirror state. In the bent optical waveguide structure according to claim 1,
A bent optical waveguide structure, wherein a convex lens is integrally provided at one end face position and / or the other end face position of the optical waveguide section. A bent optical waveguide structure according to claim 1, an optical element, and a transmission medium, wherein the optical element is disposed so as to face one end face of the optical waveguide portion in the bent optical waveguide structure. The optical transmission / reception module, wherein the transmission medium is arranged so as to face the other end face of the optical waveguide unit. A bent optical waveguide structure according to claim 1 or 2 and a pair of transmission media, wherein one of the transmission media is arranged so as to face one end face of the optical waveguide portion in the bent optical waveguide structure. An optical connector module comprising: the other of the transmission mediums disposed so as to face the other end face of the optical waveguide unit.

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