Optical connection system and optical connector

Abstract

An optical connection system (1) comprises a first optical system (S1) which is installed at a first base member (10) that includes an optical waveguide (30), a second base member (20) which is stacked on the first base member (10) and at which an optical fiber (40) is installed, and a second optical system (S2) which is installed at the second base member (20). The first optical system (S1) collimates signal light emitted from the optical waveguide (30) and then guides the signal light to the second optical system (S2). The second optical system (S2) condenses the signal light from the first optical system (S1) on the incidence end surface of the optical fiber (40).

Description

Optical connection system and optical connector

[0001] The present invention relates to an optical connection system for connecting an optical fiber and an optical waveguide, and an optical connector provided with the optical connection system.

[0002] Conventionally, optical transmission systems that transmit optical signals using optical fibers have been used in various communication systems. For example, in a data center where a large number of servers are installed, adjacent servers are connected by optical fibers for data transmission and reception. In such an optical transmission system, an optical connector is used to connect an optical waveguide installed on the substrate of the server and an optical fiber.

[0003] Patent Document 1 below describes an optical connection structure in which a rectangular fixing block having an optical fiber overlaps the upper surface of a rectangular polymer optical waveguide. In this optical connection structure, the fixing block is installed on the upper surface of the polymer optical waveguide so that one end of the optical fiber and one end of the polymer optical waveguide are arranged vertically. Reflective mirrors are respectively arranged at these ends, and the polymer optical waveguide and the optical fiber are optically connected by these reflective mirrors.

[0004] Japanese Patent Application Laid-Open No. 2004-125946

[0005] However, in the optical connection structure having the above configuration, if a misalignment occurs between the fixing block and the polymer optical waveguide in a direction parallel to the upper surface of the polymer optical waveguide, the incident position of light on the reflective mirror on the fixing block side will deviate from the position of the core of the optical fiber. Therefore, in the above configuration, it is necessary to accurately align the fixing block and the polymer optical waveguide while installing the fixing block on the upper surface of the polymer optical waveguide.

[0006] In view of such problems, an object of the present invention is to provide an optical connection system and an optical connector that can easily connect an optical waveguide and an optical fiber while suppressing optical loss.

[0007] A first aspect of the present invention relates to an optical connection system. The optical connection system according to this aspect comprises a first optical system installed on a first base member including an optical waveguide, a second base member superimposed on the first base member and on which an optical fiber is installed, and a second optical system installed on the second base member. The first optical system aligns signal light emitted from the optical waveguide and guides it to the second optical system, and the second optical system focuses the signal light from the first optical system onto the incident end face of the optical fiber.

[0008] When an optical element for aligning signal light emitted from an optical waveguide is arranged on a second base member, a misalignment between the first and second base members causes the incident state of light on this optical element to change from the proper state. As a result, the signal light is not properly aligned, or it travels along an optical path that is slightly tilted from the normal optical path. Therefore, the point of focus of the light by the second optical system shifts from the incident end face of the optical fiber (core), reducing the coupling efficiency of the signal light to the optical fiber. Consequently, when an optical element is arranged on the second base member in this manner, precise positional adjustment between the first base member (first optical system) and the second base member (second optical system) is necessary. In contrast, with the optical connection system according to this embodiment, the signal light emitted from the optical waveguide is aligned by the first optical system arranged on the first base member, so the above problems are less likely to occur. Therefore, the optical waveguide and the optical fiber can be easily connected while suppressing optical loss.

[0009] A second aspect of the present invention relates to an optical connector. The optical connector according to this aspect comprises the optical connection system according to the first aspect and the first base member.

[0010] According to the optical connector of this embodiment, since the optical system of the first embodiment is used, the same effects as in the first embodiment can be achieved.

[0011] As described above, the present invention provides an optical connection system and an optical connector that can easily connect an optical waveguide and an optical fiber while suppressing optical loss.

[0012] The effects and significance of the present invention will become even clearer from the description of the embodiments shown below. However, the embodiments shown below are merely examples of how to implement the present invention, and the present invention is not limited in any way to those described in the embodiments below.

[0013] Figure 1 is a perspective view showing the configuration of the optical connection system and optical connector according to Embodiment 1. Figure 2 is a perspective view illustrating the assembly procedure of the optical connection system according to Embodiment 1. Figure 3 is a perspective view illustrating the assembly procedure of the optical connection system according to Embodiment 1. Figure 4 is a perspective view illustrating the assembly procedure of the optical connection system according to Embodiment 1. Figure 5 is a perspective view illustrating the assembly procedure of the optical connector according to Embodiment 1. Figure 6 is a schematic diagram showing the cross-section of the optical connector when it is cut by a plane parallel to the Y-Z plane at the position C1-C2 in Figure 5, according to Embodiment 1. Figure 7 is a schematic diagram showing the configuration of the optical system of the optical connection system according to Embodiment 1. Figures 8(a) to 8(c) are diagrams showing the signal light rays corresponding to the Y-axis displacement of the second base member according to the simulation of the comparative example, respectively. Figures 9(a) to 9(c) are diagrams showing the signal light rays corresponding to the Y-axis displacement of the second base member according to the simulation of Embodiment 1, respectively. Figures 10(a) to 10(c) are diagrams showing the signal light rays corresponding to the Z-axis displacement of the second base member in the simulation of Embodiment 1, respectively. Figures 11(a) and 11(b) are graphs showing the relationship between the displacement of the second base member and the coupling loss at the incident end face in the simulation of Embodiment 1, respectively. Figures 12(a) to 12(c) are diagrams showing the Gaussian distribution of the incident end face corresponding to the Y-axis displacement of the second base member in the simulation of Embodiment 1, respectively. Figures 13(a) to 13(c) are diagrams showing the Gaussian distribution of the incident end face corresponding to the Z-axis displacement of the second base member in the simulation of Embodiment 1, respectively. Figure 14 is a schematic diagram showing the cross-section when the structure consisting of the first base member and optical element and the structure consisting of the second base member and optical element are cut by a plane parallel to the Y-Z plane at the central position in the X-axis direction, according to Embodiment 2. Figure 15 schematically shows a cross-section of the optical connector when it is cut in a plane parallel to the Y-Z plane at the same position as C1-C2 in Figure 5, according to Embodiment 2. Figure 16 schematically shows the configuration of the optical system of the optical connection system according to Embodiment 2.Figures 17(a) to 17(c) are diagrams showing the signal light rays corresponding to the Y-axis displacement of the second base member in the simulation of Embodiment 2, respectively. Figures 18(a) to 18(c) are diagrams showing the signal light rays corresponding to the Z-axis displacement of the second base member in the simulation of Embodiment 2, respectively. Figures 19(a) and 19(b) are graphs showing the relationship between the displacement of the second base member and the coupling loss at the incident end face in the simulation of Embodiment 2, respectively. Figure 20 is a schematic diagram showing the configuration of the optical system of the optical connection system in Embodiment 3. Figures 21(a) to 17(c) are diagrams showing the signal light rays corresponding to the Y-axis displacement of the second base member in the simulation of Embodiment 3, respectively. Figures 22(a) to 17(c) are diagrams showing the signal light rays corresponding to the Z-axis displacement of the second base member in the simulation of Embodiment 3, respectively. Figures 23(a) and 23(b) are graphs showing the relationship between the displacement of the second base member and the coupling loss at the incident end face in the simulation of Embodiment 3, respectively. Figure 24 is a schematic diagram showing the optical system configuration of the optical connection system according to Modification Example 1. Figure 25 is a schematic diagram showing the cross-section when the optical connector is cut in a plane parallel to the Y-Z plane at the same position as C1-C2 in Figure 5, according to Modification Example 2.

[0014] However, the drawings are for illustrative purposes only and do not limit the scope of this invention.

[0015] Embodiments of the present invention will be described below with reference to the figures. For convenience, each figure is labeled with mutually orthogonal X, Y, and Z axes. The negative Z-axis direction is the height direction of the optical connection system 1 and the optical connector 2, and the X-axis direction is the width direction of the optical connection system 1 and the optical connector 2.

[0016] <Embodiment 1> Figure 1 is a perspective view showing the configuration of the optical connection system 1 and the optical connector 2.

[0017] In Embodiment 1, four optical connection systems 1 are arranged in a line along the X-axis. Each optical connection system 1 comprises a first base member 10, a second base member 20, an optical waveguide 30, an optical fiber 40, an optical element 100 (see Figure 2), and an optical element 200. The first base member 10 and the second base member 20 are made of, for example, silicon. The cubic prototypes of the first base member 10 and the second base member 20 are subjected to an etching process to form the outer shapes of the first base member 10 and the second base member 20.

[0018] The optical connector 2 comprises four optical connection systems 1 and a fixing mechanism 3. With two adjacent optical connection systems 1 positioned adjacent to each other in the X-axis direction, the lower surfaces (positive Z-axis side) of the four optical connection systems 1 are mounted on a substrate (not shown). The fixing mechanism 3 comprises a planar portion 3a parallel to the X-Y plane and a pair of side portions 3b extending downward from both ends of the planar portion 3a in the X-axis direction. The side portions 3b have openings 3c that penetrate the side portions 3b in the X-axis direction. The fixing mechanism 3 is fitted from the upper side (negative Z-axis side) of the four optical connection systems 1, and the openings 3c of the pair of side portions 3b engage with projections 11 formed on the sides of the optical connection systems 1 on the positive X-axis side and the negative X-axis side, respectively. This fixes the second base member 20 to the first base member 10.

[0019] Figures 2-5 are perspective views illustrating the assembly procedure of the optical connection system 1 and the optical connector 2.

[0020] As shown in Figure 2, a recess 12 and two inclined surfaces 13 and 14 are formed on the upper surface of the first base member 10. Inside the first base member 10, an optical waveguide 30 is formed for transmitting signal light incident from the negative Y-axis end of the first base member 10 in the positive Y-axis direction. The core of the optical waveguide 30 is made of, for example, silicon. The recess 12 has a triangular shape in side view. The inclined surfaces 13 and 14 are fitted with inclined surfaces 23 and 24 of the second base member 20, which will be described later.

[0021] In Embodiment 1, a tapered optical waveguide 31 is formed at the positive Y-axis end of the optical waveguide 30. The tapered optical waveguide 31 expands the beam size of the signal light from the optical waveguide 30 while totally reflecting it. The tapered shape of the tapered optical waveguide 31 is set so that the beam diameter at the positive Y-axis exit end face of the tapered optical waveguide 31 is approximately the same as the beam diameter at the incident end face F1 (see Figure 7) of the optical fiber 40. The tapered optical waveguide 31 is sometimes called a spot size converter. The signal light from the optical waveguide 30 is emitted into the recess 12 after its beam size has been expanded by the tapered optical waveguide 31.

[0022] The optical element 100 has a shape substantially similar to the recess 12 and is made of a material with high light transmittance (for example, glass or resin). A slope is formed on the lower side of the optical element 100, and the first mirror 101 is formed by depositing a highly reflective metallic material onto this slope. In Figure 2, for convenience, the first mirror 101 is shown as a halftone dot. A first lens 102 is formed on the upper side of the optical element 100. The first lens 102 is a collimator lens. The first mirror 101 and the first lens 102 are integrally formed in the optical element 100 and constitute the first optical system S1. The optical element 100 is installed in the recess 12 of the first base member 10 using adhesive. In this way, the assembly of the first base member 10 is completed.

[0023] As shown in Figure 3, an opening 21 and a support portion 22 are formed on the upper surface of the second base member 20. The opening 21 is open to the upper side of the second base member 20, and the negative Y-axis end of the opening 21 is open to the lower side of the second base member 20. The support portion 22 has a valley shape of a certain depth that extends in the Y-axis direction. The valley shape when viewed in the Y-axis direction is V-shaped. Two slopes 23 and 24 are formed on the lower surface of the second base member 20. The slopes 23 and 24 are placed on the slopes 13 and 14 of the first base member 10 (see Figure 2), respectively.

[0024] The optical element 200 has a shape that fits into the aperture 21 and is made of a material with high light transmittance (for example, glass or resin). A bevel is formed on the negative Y-axis end of the optical element 200, and a second mirror 201 is formed by depositing a highly reflective metal material onto this bevel. In Figure 3, for convenience, the second mirror 201 is shown as a halftone dot. A second lens 202 is formed on the positive Y-axis end of the optical element 200, as this end has a curved shape. The second lens 202 is a focusing lens. The second mirror 201 and the second lens 202 are integrally formed in the optical element 200 and constitute the second optical system S2. A core 41 is formed inside the optical fiber 40. The core 41 is a single-mode core.

[0025] The optical element 200 is inserted into the opening 21 of the second base member 20, and the slanted surface on the negative side of the Y axis and the lower surface near the positive side of the Y axis of the optical element 200 are installed in the opening 21 using adhesive. The optical fiber 40 is installed in the support portion 22 using adhesive. In this way, the assembly of the second base member 20 is completed.

[0026] As shown in Figure 4, the assembled second base member 20 is placed on top of the assembled first base member 10 from above. At this time, the inclined surfaces 23 and 24 of the second base member 20 are superimposed on the inclined surfaces 13 and 14 of the first base member 10. This positions the second base member 20 relative to the first base member 10. In this way, the assembly of one optical connection system 1 is completed.

[0027] As shown in Figure 5, the four assembled first base members 10 are fixed to a substrate (not shown) parallel to the X-Y plane so that they are aligned in the X-axis direction. The fixing mechanism 3 is then fitted in from above the four optical connection systems 1. A projection 11 is formed on the X-axis negative side of the first base member 10 of the optical connection system 1 furthest to the X-axis negative side, and on the X-axis positive side of the first base member 10 of the optical connection system 1 furthest to the X-axis positive side.

[0028] When the fixing mechanism 3 is fitted, the pair of openings 3c of the fixing mechanism 3 engage with the two protrusions 11. At this time, the lower surface of the flat portion 3a of the fixing mechanism 3 abuts against the upper surface of the second base member 20 of the four optical connection systems 1. This suppresses misalignment in the Z-axis direction, and the second base member 20 is fixed to the first base member 10. In this way, the optical connector 2 shown in Figure 1 is completed.

[0029] Figure 6 schematically shows a cross-section of the optical connector 2 when it is cut along a plane parallel to the Y-Z plane at the position C1-C2 in Figure 5.

[0030] As described above, the second base member 20 is superimposed on the first base member 10, so that the inclined surfaces 23 and 24 of the second base member 20 are in contact with the inclined surfaces 13 and 14 of the first base member 10. Also, the tapered optical waveguide 31 and the optical element 100 are adjacent in the Y-axis direction. The optical elements 100 and 200 face each other in the Z-axis direction, and the optical element 200 and the optical fiber 40 face each other in the Y-axis direction.

[0031] Figure 7 is a schematic diagram showing the configuration of the optical system of the optical connection system 1.

[0032] The first optical system S1 directs the signal light emitted from the tapered optical waveguide 31 in the positive Y-axis direction to the second optical system S2 after translating it into parallel light. Specifically, the first mirror 101 of the first optical system S1 reflects the signal light from the tapered optical waveguide 31 in the negative Z-axis direction, and the first lens 102 of the first optical system S1 focuses the signal light from the first mirror 101 into parallel light.

[0033] The second optical system S2 focuses the signal light from the first optical system S1 onto the incident end face F1 on the negative Y-axis side of the optical fiber 40. Specifically, the second mirror 201 of the second optical system S2 reflects the signal light from the first optical system S1 in the positive Y-axis direction, and the second lens 202 of the second optical system S2 focuses the signal light from the second mirror 201 onto the incident end face F1 of the optical fiber 40. The incident end face F1 is the incident end face of the single-mode core 41 of the optical fiber 40.

[0034] By the way, in the configuration where the first lens 102 for aligning the signal light emitted from the optical waveguide 30 is located on the second base member 20 (comparative example), if a misalignment occurs between the first base member 10 and the second base member 20, the incident state of light on the first lens 102 changes from the proper state. As a result, the signal light is not properly aligned, or it travels along an optical path that is slightly tilted from the normal optical path. Therefore, the light collection position by the second optical system S2 shifts from the incident end face F1 of the core 41 of the optical fiber 40, and the coupling efficiency of the signal light to the optical fiber 40 decreases. For this reason, when the first lens 102 is located on the second base member 20 as in the comparative example, it is necessary to precisely adjust the position between the first base member 10 (first optical system S1) and the second base member 20 (second optical system S2).

[0035] In contrast, according to this embodiment, the signal light emitted from the optical waveguide 30 is made into parallel light by the first optical system S1 arranged on the first base member 10, so the above-mentioned problems do not occur. Therefore, the optical waveguide 30 and the optical fiber 40 can be easily connected while suppressing optical loss.

[0036] Next, we will describe the simulations performed by the inventors to examine the extent of optical loss caused by the misalignment of the second base member 20 in the comparative example and the present embodiment.

[0037] As shown in Figures 8(a) to 8(c), in the simulation of the comparative example, the emission point of the signal light from the tapered optical waveguide 31 was set to P1, and the positions of the emission point P1 and the first mirror 101 were fixed. The first lens 102, the second mirror 201, the second lens 202, and the incident end face F1 of the optical fiber 40 were provided on the second base member 20, and these were moved according to the displacement of the second base member 20. On the other hand, as shown in Figures 9(a) to 10(c), in the simulation of this embodiment, the positions of the emission point P1, the first mirror 101, and the first lens 102 were fixed. The second mirror 201, the second lens 202, and the incident end face F1 of the optical fiber 40 were provided on the second base member 20, and these were moved according to the displacement of the second base member 20.

[0038] Figures 8(a) to 8(c) show the signal light rays when the Y-axis displacement of the second base member 20 is 0 μm, +30 μm, and -30 μm, respectively, in the simulation of the comparative example.

[0039] In the comparative example, since the first lens 102 is positioned on the second base member 20, the first lens 102 shifts in the Y-axis direction according to the Y-axis displacement of the second base member 20, and the incident state of light on the first lens 102 changes. Therefore, as shown in Figures 8(b) and 8(c), when the second base member 20 is shifted in the Y-axis direction, the signal light reflected by the second mirror 201 travels along an optical path that is slightly inclined in the Z-axis direction from the optical path when there is no positional displacement, and the focusing position of the signal light by the second lens 202 is shifted in the Z-axis direction with respect to the incident end face F1. Consequently, in the comparative example, when the second base member 20 is shifted in the Y-axis direction, the focusing position of the signal light with respect to the incident end face F1 changes significantly, and the coupling efficiency of the signal light to the core 41 of the optical fiber 40 decreases.

[0040] In the comparative example, when the second base member 20 is displaced in the Z-axis direction, the position of the first lens 102 changes in the Z-axis direction according to the displacement of the second base member 20. In this case, the optical path length from the exit point P1 to the first lens 102 changes, so the signal light from the first mirror 101 is not properly parallelized. Consequently, the focusing position of the signal light relative to the incident end face F1 changes significantly in the Y-axis direction, and the coupling efficiency of the signal light to the core 41 of the optical fiber 40 decreases.

[0041] Figures 9(a) to 9(c) show the signal light rays when the Y-axis displacement of the second base member 20 is 0 μm, +30 μm, and -30 μm, respectively, in the simulation of Embodiment 1.

[0042] According to Embodiment 1, since the first lens 102 is disposed on the first base member 10, the position of the first lens 102 does not change according to the displacement of the second base member 20 in the Y-axis direction. As a result, even when the second base member 20 is displaced in the Y-axis direction as shown in FIGS. 9(b) and 9(c), the signal light collimated by the first lens 102 travels substantially parallel to the optical path in the case of no displacement, and is focused at a position substantially the same as the focusing position in the case of no displacement. Therefore, in Embodiment 1, even when the second base member 20 is displaced in the Y-axis direction, the focusing position of the signal light with respect to the incident end face F1 hardly changes, and the coupling efficiency of the signal light with respect to the core 41 of the optical fiber 40 is maintained high.

[0043] FIGS. 10(a) to 10(c) are diagrams showing the light rays of the signal light in the case where the displacement of the second base member 20 in the Z-axis direction is 0 μm, +30 μm, and -30 μm, respectively, in the simulation of Embodiment 1.

[0044] Also in this case, the position of the first lens 102 does not change according to the displacement of the second base member 20 in the Z-axis direction. Further, even when the second base member 20 is displaced in the Z-axis direction, the signal light collimated by the first lens 102 travels substantially the same optical path as in the case of no displacement, and is focused in substantially the same state as in the case of no displacement. Therefore, in Embodiment 1, even when the second base member 20 is displaced in the Z-axis direction, the focusing state of the signal light with respect to the incident end face F1 hardly changes, and the coupling efficiency of the signal light with respect to the core 41 of the optical fiber 40 is maintained high.

[0045] FIGS. 11(a) and 11(b) are graphs showing the relationship between the displacement of the second base member 20 and the coupling loss at the incident end face F1 in the simulation of Embodiment 1.

[0046] As shown in FIG. 11(a), when the absolute value of the displacement of the second base member 20 in the Y-axis direction increases, the coupling loss of the signal light at the incident end face F1 increases. Usually, since the coupling loss can be allowed up to about -1 dB, if the tolerance range of the displacement in the Y-axis direction is in the range of -15 μm or more and +15 μm or less, the coupling loss can be suppressed within the allowable range.

[0047] As shown in Fig. 11(b), regardless of the displacement of the second base member 20 in the Z-axis direction, the coupling loss of the signal light at the incident end face F1 hardly changes. Therefore, the allowable range (tolerance range) of the displacement in the Z-axis direction can be set to be sufficiently wide.

[0048] Figs. 12(a) to (c) are diagrams showing the Gaussian distribution of the incident end face F1 when the displacement of the second base member 20 in the Y-axis direction is 0 μm, +10 μm, and -10 μm, respectively, in the simulation of Embodiment 1. Figs. 13(a) to (c) are diagrams showing the Gaussian distribution of the incident end face F1 when the displacement of the second base member 20 in the Z-axis direction is 0 μm, +10 μm, and -10 μm, respectively, in the simulation of Embodiment 1.

[0049] As shown in Fig. 12(a), when the Gaussian distribution is properly set in the case where there is no displacement of the second base member 20 in the Y-axis direction, as shown in Figs. 12(b) and (c), even when the displacement of the second base member 20 in the Y-axis direction is +10 μm and -10 μm, the Gaussian distribution becomes proper, similar to the case where there is no displacement in the Y-axis direction. Also, as shown in Fig. 13(a), when the Gaussian distribution is properly set in the case where there is no displacement of the second base member 20 in the Z-axis direction, as shown in Figs. 13(b) and (c), even when the displacement of the second base member 20 in the Z-axis direction is +10 μm and -10 μm, the Gaussian distribution becomes proper, similar to the case where there is no displacement in the Z-axis direction.

[0050] Thus, according to Embodiment 1, even when the second base member 20 is displaced in the Y-axis direction and the Z-axis direction, the Gaussian distribution at the incident end face F1 becomes proper. From this, it can be understood that in Embodiment 1, the optical loss of the signal light incident on the optical fiber 40 can be suppressed, and the optical coupling efficiency of the signal light to the optical fiber 40 can be maintained high.

[0051] <Effect of Embodiment 1> According to Embodiment 1, the following effects are achieved.

[0052] As shown in Figure 7, the optical connection system 1 includes a first optical system S1 installed on a first base member 10 including an optical waveguide 30, a second base member 20 superimposed on the first base member 10 and on which an optical fiber 40 is installed, and a second optical system S2 installed on the second base member 20. The first optical system S1 aligns the signal light emitted from the optical waveguide 30 and guides it to the second optical system S2, and the second optical system S2 focuses the signal light from the first optical system S1 onto the incident end face F1 of the optical fiber 40.

[0053] As shown in Figures 8(a) to 8(c), when the first lens 102 for aligning the signal light emitted from the optical waveguide 30 is located on the second base member 20 (comparative example), if a misalignment occurs between the first base member 10 and the second base member 20, the incident state of light on the first lens 102 changes from the proper state. As a result, the signal light is not properly aligned, or it travels along an optical path that is slightly tilted from the normal optical path. Consequently, the light collection position by the second optical system S2 shifts from the incident end face F1 of the core 41 of the optical fiber 40, and the coupling efficiency of the signal light to the optical fiber 40 decreases. Therefore, when the first lens 102 is located on the second base member 20 in this manner, it is necessary to precisely adjust the position between the first base member 10 (first optical system S1) and the second base member 20 (second optical system S2).

[0054] In contrast, according to the above configuration of Embodiment 1, as shown in Figures 9(a) to 10(c), the signal light emitted from the optical waveguide 30 is made into parallel light by the first optical system S1 arranged on the first base member 10, so the above-mentioned problems are less likely to occur. Therefore, the optical waveguide 30 and the optical fiber 40 can be easily connected while suppressing optical loss.

[0055] The first optical system S1 includes a first mirror 101 that bends the optical path of the signal light emitted from the optical waveguide 30 toward the second base member 20, and a first lens 102 that aligns the signal light emitted from the optical waveguide 30 into parallel light.

[0056] With this configuration, the combination of the first mirror 101 and the first lens 102 makes it possible to parallelize the signal light emitted from the optical waveguide 30 and guide it to the second optical system S2.

[0057] The first mirror 101 and the first lens 102 are integrated into a single unit.

[0058] This configuration eliminates the need for positional adjustment between the first mirror 101 and the first lens 102, and also reduces the number of parts.

[0059] The second optical system S2 includes a second mirror 201 that bends the optical path of the signal light incident from the first optical system S1, and a second lens 202 that focuses the signal light reflected by the second mirror 201 onto the incident end face F1 of the optical fiber 40.

[0060] With this configuration, the combination of the second mirror 201 and the second lens 202 makes it possible to focus the signal light incident from the first optical system S1 onto the incident end face F1 of the optical fiber 40.

[0061] The second mirror 201 and the second lens 202 are integrated into a single unit.

[0062] This configuration eliminates the need for positional adjustment between the second mirror 201 and the second lens 202, and also reduces the number of parts.

[0063] The system includes a positioning mechanism (inclined surfaces 13, 14, 23, 24) that positions the second base member 20 relative to the first base member 10 by overlapping the second base member 20 with the first base member 10.

[0064] With this configuration, the second base member 20 can be positioned on the first base member 10 by overlapping it with the first base member 10. Therefore, the installation work of the second base member 20 on the first base member 10 can be simplified.

[0065] The optical connector 2 comprises an optical connection system 1 and a first base member 10.

[0066] In this configuration as well, the first optical system S1 arranged on the first base member 10 aligns the signal light emitted from the optical waveguide 30, thus preventing a decrease in the coupling efficiency of the signal light to the optical fiber 40. Therefore, the optical waveguide 30 and the optical fiber 40 can be easily connected while suppressing optical loss.

[0067] The optical connector 2 further includes a fixing mechanism 3 that fixes the second base member 20 to the first base member 10 while suppressing displacement of the second base member 20 in the negative Z-axis direction (direction away from the first base member 10).

[0068] This configuration allows the second base member 20 (second optical system S2) to be fixed to the first base member 10 while suppressing misalignment of the second base member 20 in the Z-axis direction.

[0069] <Embodiment 2> In Embodiment 2, the second optical system S2 is modified compared to Embodiment 1 so as to suppress coupling loss caused by misalignment of the second base member 20 in the Y-axis direction.

[0070] Figure 14 schematically shows the cross-sections of a structure consisting of a first base member 10 and optical elements 100 and 300, and a structure consisting of a second base member 20 and optical element 200, when cut by a plane parallel to the Y-Z plane at the central position in the X-axis direction.

[0071] In Embodiment 2, the shapes of the first base member 10, the second base member 20, and the optical element 200 are changed compared to Embodiment 1, and an optical element 300 is added. The configurations that differ from Embodiment 1 will be described below.

[0072] An opening 15 and a support portion 16 are formed near the positive Y-axis end of the first base member 10. The support portion 16 has the same configuration as the support portion 22 in Embodiment 1. The opening 15 is adjacent to the negative Y-axis side of the support portion 16. The opening 15 is open above the first base member 10, and a slope is formed at the negative Y-axis end of the opening 15. The optical element 300 has a triangular prism shape and is made of a material with high light transmittance (for example, glass or resin). A slope is formed on the lower side of the optical element 300, and a mirror 301 is formed by depositing a highly reflective metal material onto this slope.

[0073] The optical element 300 is installed on the inclined surface on the negative Y-axis side of the opening 15 of the first base member 10 using adhesive. The optical fiber 40 is installed on the support portion 16 using adhesive. The optical element 300 and the optical fiber 40 face each other in the Y-axis direction through the opening 15.

[0074] An opening 25 is formed on the lower surface side of the second base member 20. The optical element 200 includes a portion 200a that faces the optical element 100 and extends in the Y-axis direction, a portion 200b that extends in the Z-axis direction from the Y-axis positive end, and a portion 200c that connects portions 200a and 200b. The Y-axis negative end of portion 200a has a concave shape, and a mirror 211 is formed by depositing a highly reflective metal material onto this end. The Y-axis positive end of portion 200a also has a concave shape, and a mirror 212 is formed by depositing a highly reflective metal material onto this end. A lens 213 is formed at the lower end of portion 200b.

[0075] Mirrors 211 and 212 are a pair of mirrors facing each other in the Y-axis direction, and each has a concave shape that is symmetrical with respect to a plane parallel to the X-Z plane. As shown in Figure 16, the pair of mirrors 211 and 212 have a common imaging position at an intermediate position P2 between them. If parallel light in the negative Z-axis direction is incident on the concave shapes (reflective surfaces) of the pair of mirrors 211 and 212, the pair of mirrors 211 and 212 reflect the incident light in opposite directions, focusing it at the intermediate position P2 between the pair of mirrors 211 and 212.

[0076] Lens 213 is a condensing lens. The pair of mirrors 211 and 212 and lens 213 are integrally formed in the optical element 200 and constitute the second optical system S2. The optical element 200 is inserted into the opening 25 of the second base member 20, and the upper surface of the optical element 200 is set in the opening 25 using adhesive.

[0077] In this embodiment, it is preferable that the pair of mirrors 211 and 212 are anamorphic aspherical mirrors (mirrors with different curvatures in the X-axis direction and the Y-axis direction). In this case, the curvature of the pair of mirrors 211 and 212 in the Y-axis direction is set to be greater than the curvature in the X-axis direction. This makes it possible to suppress the shift in the direction of propagation of the signal light between the imaging position of the signal light focused by the mirror 211 in the Y-axis direction and the imaging position of the signal light focused by the mirror 211 in the X-axis direction.

[0078] In other words, as shown in Figure 14, when the signal light from the optical waveguide 30 is reflected by the first mirror 101 which is tilted with respect to the X-Y plane, even if the signal light from the optical waveguide 30 is approximately circular, the beam diameters of the reflected signal light will be different in the X-axis direction and the Y-axis direction. For this reason, the numerical aperture of the signal light relative to the mirror 211 will be different in the Y-axis direction and the X-axis direction. In this case, if the curvature of the concave shape of the mirror 211 is uniform over its entire circumference, the difference in numerical aperture will cause the imaging position of the signal light in the Y-axis direction and the imaging position of the signal light in the Z-axis direction to be shifted in the direction of propagation of the signal light.

[0079] Such misalignment of the image formation position can be eliminated by making the curvature of the concave shape of the mirror 211 different in the Y-axis direction and the X-axis direction, as described above. For this reason, it is preferable that the pair of mirrors 211 and 212 be composed of anamorphic aspherical mirrors with a concave shape that can suppress such misalignment of the image formation position.

[0080] On the other hand, if the curvature of the mirror 211 is made different in the Y-axis direction and the X-axis direction, astigmatism occurs in the signal light reflected by the mirror 211. However, since the concave shape of the other mirror 212, which is positioned opposite the mirror 211, is symmetrical with the concave shape of the mirror 211 (anamorphic aspherical), the astigmatism generated in one mirror 211 is canceled out by the other mirror 212. As a result, the second optical system S2 (Gaussian distribution optical system) including these mirrors 211 and 212 can be made into an aberration-free optical system.

[0081] Figure 15 schematically shows a cross-section of the optical connector 2 when it is cut in a plane parallel to the Y-Z plane at the same position as C1-C2 in Figure 5.

[0082] Similar to Embodiment 1, the second base member 20 is superimposed on the first base member 10, so that the inclined surfaces 23 and 24 of the second base member 20 come into contact with the inclined surfaces 13 and 14 of the first base member 10. As a result, the first lens 102 and mirror 211 face each other in the Z-axis direction, and the mirrors 212 and 301 face each other in the Z-axis direction. In addition, the lens 213 protruding from the second base member 20 in the positive Z-axis direction is housed in the opening 15 of the first base member 10. As a result, the mirror 301, lens 213 and optical fiber 40 are aligned in the Y-axis direction. Then, similar to Embodiment 1, the fixing mechanism 3 is installed on the four optical connection systems 1, and the optical connector 2 is completed.

[0083] Figure 16 is a schematic diagram showing the configuration of the optical system of the optical connection system 1.

[0084] Similar to Embodiment 1, the first optical system S1 directs the signal light emitted from the tapered optical waveguide 31 in the positive Y-axis direction, aligns it, and guides it to the second optical system S2. At this time, the first optical system S1 causes the alignable signal light to be incident on the mirror 211 in the Z-axis direction.

[0085] The second optical system S2 focuses the signal light from the first optical system S1 onto the incident end face F1 on the negative Y-axis side of the optical fiber 40. Mirror 211 reflects the signal light from the first optical system S1 in the positive Y-axis direction and focuses it onto an intermediate position P2. Mirror 212 reflects the signal light from the intermediate position P2 in the positive Z-axis direction. Since the pair of mirrors 211 and 212 each have a concave shape that is symmetrical to each other, the signal light reflected by mirror 212 becomes parallel light again. Mirror 301 reflects the signal light from mirror 212 in the positive Y-axis direction. Lens 213 focuses the signal light from mirror 301 onto the incident end face F1 of the optical fiber 40.

[0086] Next, we will describe a simulation similar to that in Embodiment 1, which the inventors performed to examine how much light loss occurs due to the misalignment of the second base member 20 in this embodiment.

[0087] In the simulation of this embodiment, the positions of the exit point P1, the first mirror 101, the first lens 102, and the mirror 301 were fixed. A pair of mirrors 211 and 212, a lens 213, and the incident end face F1 of the optical fiber 40 were provided on the second base member 20, and these were moved in accordance with the displacement of the second base member 20.

[0088] Figures 17(a) to 17(c) show the signal light rays when the Y-axis displacement of the second base member 20 is 0 μm, +30 μm, and -30 μm, respectively, in the simulation of Embodiment 2.

[0089] According to Embodiment 2, similar to Embodiment 1, the first lens 102 is positioned on the first base member 10. Therefore, even if the second base member 20 is misaligned in the Y-axis direction as shown in Figures 17(b) and (c), the signal light is properly parallelized by the first lens 102 and guided by the pair of mirrors 211 and 212 to a position of mirror 301 that is almost the same as in Figure 17(a). As a result, even if the second base member 20 is misaligned in the Y-axis direction, the focusing position at the incident end face F1 is almost the same as the focusing position when there is no misalignment.

[0090] Figures 18(a) to 18(c) show the signal light rays when the Z-axis displacement of the second base member 20 is 0 μm, +30 μm, and -30 μm, respectively, in the simulation of Embodiment 2.

[0091] In this case as well, even if the second base member 20 is misaligned in the Z-axis direction, the signal light from the first lens 102 is guided as parallel light to approximately the same position on the mirror 301 by the pair of mirrors 211 and 212. If the second base member 20 is misaligned in the Z-axis direction, the position of the lens 213 will shift in the Z-axis direction, causing the focusing position at the incident end face F1 to shift slightly in the Z-axis direction. However, since the signal light incident on the lens 213 is parallel light, the shift in the focusing position at the incident end face F1 is suppressed.

[0092] Figures 19(a) and 19(b) are graphs showing the relationship between the positional displacement of the second base member 20 and the coupling loss at the incident end face F1, respectively, in the simulation of Embodiment 2.

[0093] As shown in Figure 19(a), the coupling loss of the signal light at the incident end face F1 remains virtually unchanged regardless of the Y-axis displacement of the second base member 20. Therefore, a sufficiently wide tolerance range for the Y-axis displacement can be set.

[0094] As shown in Figure 19(b), when the absolute value of the Z-axis displacement of the second base member 20 increases, the coupling loss of the signal light at the incident end face F1 increases. Normally, coupling loss can be tolerated up to about -1 dB, so if the tolerance range for the Z-axis displacement is between -15 μm and +15 μm, the coupling loss can be kept within the acceptable range.

[0095] <Effects of Embodiment 2> As shown in Figure 16, the second optical system S2 includes a pair of mirrors 211 and 212 facing each other in the Y-axis direction (first direction). The pair of mirrors 211 and 212 each have a concave shape that is symmetrical with respect to each other, and have an optical effect of reflecting light incident on each concave shape in the Z-axis direction (second direction) perpendicular to the Y-axis direction (first direction) in opposite directions, and focusing the light at an intermediate position P2 between the pair of mirrors 211 and 212. The first optical system S1 causes signal light to be incident on one of the pair of mirrors 211 and 212 in the Z-axis direction (second direction).

[0096] With this configuration, as shown in Figure 19(a), the tolerance for positional displacement in the Y-axis direction can be increased.

[0097] <Embodiment 3> In Embodiment 1, the first optical system S1 was composed of a first mirror 101 and a first lens 102. In contrast, in this embodiment, the first optical system S1 is composed of a concave mirror 103.

[0098] Figure 20 is a schematic diagram showing the configuration of the optical system of the optical connection system 1.

[0099] In this embodiment, compared to Embodiment 1, a concave mirror 103 is provided instead of the first mirror 101 and the first lens 102. The concave mirror 103 is formed on the optical element 100. The concave mirror 103 reflects the optical path of the signal light emitted from the tapered optical waveguide 31 in the positive Z-axis direction and also aligns the signal light emitted from the tapered optical waveguide 31. Preferably, the concave mirror 103 is an anamorphic aspherical mirror (a mirror with different curvatures in the X-axis direction and the Y-axis direction).

[0100] Next, we will describe a simulation similar to that in Embodiment 1, which the inventors performed to investigate how much optical loss occurs due to the misalignment of the second base member 20.

[0101] In the simulation of this embodiment, the positions of the exit point P1 and the concave mirror 103 were fixed. The second mirror 201, the second lens 202, and the incident end face F1 of the optical fiber 40 were provided on the second base member 20, and these were moved in accordance with the displacement of the second base member 20.

[0102] Figures 21(a) to (c) show the signal light rays when the Y-axis displacement of the second base member 20 is 0 μm, +30 μm, and -30 μm, respectively, in the simulation of Embodiment 3.

[0103] According to Embodiment 3, since the concave mirror 103 is positioned on the first base member 10, the position of the concave mirror 103 does not change in accordance with the Y-axis displacement of the second base member 20. As a result, even if the second base member 20 is displaced in the Y-axis direction, the signal light parallelized by the concave mirror 103 is suppressed from tilting relative to the optical path when there is no displacement, and the focusing position at the incident end face F1 is approximately the same as the focusing position when there is no displacement.

[0104] Figures 22(a) to (c) show the signal light rays when the Z-axis displacement of the second base member 20 is 0 μm, +30 μm, and -30 μm, respectively, in the simulation of Embodiment 3.

[0105] In this case as well, the position of the concave mirror 103 does not change in accordance with the Z-axis displacement of the second base member 20. Furthermore, even if the second base member 20 moves in the Z-axis direction, the signal light does not tilt relative to the optical path when there is no displacement, and the focusing position at the incident end face F1 is approximately the same as the focusing position when there is no displacement.

[0106] Figures 23(a) and 23(b) are graphs showing the relationship between the displacement of the second base member 20 and the coupling loss at the incident end face F1, respectively, in the simulation of Embodiment 3.

[0107] As shown in Figure 23(a), when the absolute value of the Y-axis displacement of the second base member 20 increases, the coupling loss of the signal light at the incident end face F1 increases. Normally, coupling loss can be tolerated up to about -1 dB, so if the tolerance range for the Y-axis displacement is between -7 μm and +7 μm, the coupling loss can be kept within the acceptable range.

[0108] As shown in Figure 23(b), the coupling loss of the signal light at the incident end face F1 remains virtually unchanged regardless of the Z-axis displacement of the second base member 20. Therefore, a sufficiently wide tolerance range for the Z-axis displacement can be set.

[0109] <Effects of Embodiment 3> As shown in Figure 20, the first optical system S1 includes a concave mirror 103 that bends the optical path of the signal light emitted from the optical waveguide 30 in the negative Z-axis direction (direction toward the second base member 20) and rectifies the signal light emitted from the optical waveguide 30 into parallel light.

[0110] With this configuration, a single concave mirror 103 can rectify the signal light emitted from the optical waveguide 30 and guide it to the second optical system S2, thus simplifying the configuration of the first optical system S1 compared to Embodiment 1.

[0111] <Example of modification 1> In Embodiment 1, the signal light incident on the first optical system S1 was emitted from the optical waveguide 30 and the tapered optical waveguide 31, but it is not limited to these, and may also be emitted from the polymer optical waveguide 32.

[0112] Figure 24 is a schematic diagram showing the configuration of the optical system of the optical connection system 1.

[0113] In this modified example, compared to Embodiment 1, a polymer optical waveguide 32 is used instead of the optical waveguide 30 and tapered optical waveguide 31. Since the refractive index of the polymer optical waveguide 32 is about 1.5, the beam diameter at the exit end face on the positive Y-axis side of the polymer optical waveguide 32 is about the same as the beam diameter at the input end face F1 of the optical fiber 40. As a result, the tapered optical waveguide 31 used to adjust the beam diameter can be omitted, as in Embodiment 1.

[0114] In embodiments 2 and 3, a polymer optical waveguide 32 may be used instead of the optical waveguide 30 and the tapered optical waveguide 31.

[0115] <Example of modification 2> In Embodiment 2, the pair of mirrors 211, 212 and lens 213 of the second optical system S2 are provided on one optical element 200, but the invention is not limited to this, and may be provided on multiple optical elements.

[0116] Figure 25 schematically shows a cross-section of the optical connector 2 when it is cut in a plane parallel to the Y-Z plane at the same position as C1-C2 in Figure 5.

[0117] In this embodiment, an optical element 400 is added compared to Embodiment 2. A lens 401 is formed at the negative Y-axis end of the optical element 400, as this end has a curved shape. The lens 401 is configured similarly to the lens 213 in Embodiment 2. The optical element 400 is installed in an opening 26 formed below the second base member 20 using adhesive. The pair of mirrors 211, 212 and the lens 401 constitute the second optical system S2. The same effects as in Embodiment 2 are achieved in this modified example as well.

[0118] In Embodiment 2 and Modified Example 2, the pair of mirrors 211 and 212 of the second optical system S2 are provided on a single optical element 200. However, the invention is not limited to this, and the mirrors may be provided on two separate optical elements installed on the second base member 20.

[0119] Furthermore, in Embodiments 1, 3 and Modification 1, the second mirror 201 and the second lens 202 of the second optical system S2 are provided on a single optical element 200, but the invention is not limited to this, and they may be provided on two separate optical elements installed on the second base member 20. In Embodiments 1, 2 and Modifications 1, 2, the first mirror 101 and the first lens 102 are formed on a single optical element 100, but the invention is not limited to this, and they may be provided on two separate optical elements installed on the first base member 10.

[0120] <Other Modification Examples> In the above embodiment and modification examples, the signal light from the tapered optical waveguide 31 or polymer optical waveguide 32 is reflected by the first mirror 101 and then parallelized by the first lens 102. However, it is not limited to this, and the light may be parallelized by the first lens 102 and then reflected by the first mirror 101. In other words, the arrangement order of the first mirror 101 and the first lens 102 may be reversed.

[0121] In embodiments 1, 3 and modified example 1 described above, the signal light from the first optical system S1 was reflected by the second mirror 201 and then focused by the second lens 202. However, it is not limited to this configuration; the light may be focused by the second lens 202 and then reflected by the second mirror 201. In other words, the arrangement order of the second mirror 201 and the second lens 202 may be reversed.

[0122] In the above embodiments and modifications, the first lens 102, the second lens 202, and lenses 213 and 401 were single-surface refractive lenses, but are not limited to these; Fresnel lenses or diffractive lenses may also be used. Furthermore, the pair of mirrors 211 and 212 were single-surface concave mirrors, but are not limited to these; Fresnel mirrors or diffractive mirrors may also be used.

[0123] In the above embodiments and modifications, the number of optical connection systems 1 arranged in the optical connector 2 is not limited to four, but may be one, two, three, or five or more.

[0124] Embodiments of the present invention can be modified in various ways as appropriate within the scope of the technical idea set forth in the claims.

[0125] (Note) The above description of embodiments discloses the following technologies.

[0126] (Technical 1) An optical connection system comprising: a first optical system installed on a first base member including an optical waveguide; a second base member superimposed on the first base member and on which an optical fiber is installed; and a second optical system installed on the second base member, wherein the first optical system aligns signal light emitted from the optical waveguide and guides it to the second optical system, and the second optical system focuses the signal light from the first optical system onto the incident end face of the optical fiber.

[0127] When an optical element for aligning signal light emitted from an optical waveguide is placed on a second base member, a misalignment between the first and second base members causes the incident state of light on this optical element to change from the proper state. As a result, the signal light is not properly aligned, or it travels along an optical path that is slightly tilted from the normal optical path. Therefore, the point of focus of the light by the second optical system shifts from the incident end face of the optical fiber (core), reducing the coupling efficiency of the signal light to the optical fiber. Consequently, when an optical element is placed on the second base member in this manner, precise positional adjustment between the first base member (first optical system) and the second base member (second optical system) is necessary. In contrast, according to the above technology, the signal light emitted from the optical waveguide is aligned by the first optical system placed on the first base member, so the above problems are less likely to occur. Therefore, the optical waveguide and the optical fiber can be easily connected while suppressing optical loss.

[0128] (Technology 2) An optical connection system according to Technology 1, wherein the first optical system comprises a first mirror that bends the optical path of the signal light emitted from the optical waveguide toward the second base member, and a first lens that aligns the signal light emitted from the optical waveguide.

[0129] According to this technology, the combination of the first mirror and the first lens makes it possible to parallelize the signal light emitted from the optical waveguide and guide it to the second optical system.

[0130] (Technology 3) An optical connection system as described in Technology 2, characterized in that the first mirror and the first lens are integrated.

[0131] This technology eliminates the need for positional adjustment between the first mirror and the first lens, and also reduces the number of parts.

[0132] (Technology 4) An optical connection system according to Technology 1, wherein the first optical system includes a concave mirror that bends the optical path of the signal light emitted from the optical waveguide toward the second base member and rectifies the signal light emitted from the optical waveguide into parallel light.

[0133] This technology allows a single concave mirror to align the signal light emitted from the optical waveguide and guide it to the second optical system, thereby simplifying the configuration of the first optical system.

[0134] (Technology 5) An optical connection system according to any one of Technology 1 to 4, wherein the second optical system comprises a second mirror that bends the optical path of the signal light incident from the first optical system, and a second lens that focuses the signal light reflected by the second mirror onto the incident end face of the optical fiber.

[0135] According to this technology, the combination of the second mirror and the second lens makes it possible to focus the signal light incident from the first optical system onto the incident end face of the optical fiber.

[0136] (Technical 6) An optical connection system as described in Technical 5, characterized in that the second mirror and the second lens are integrated.

[0137] This technology eliminates the need for positional adjustment between the second mirror and the second lens, and also reduces the number of parts.

[0138] (Technology 7) An optical connection system according to any one of Technology 1 to 4, wherein the second optical system comprises a pair of mirrors facing each other in a first direction, the pair of mirrors each having a concave shape symmetrical to each other, and having an optical effect of reflecting light incident on each of the concave shapes in opposite directions in a second direction perpendicular to the first direction, and focusing the light at an intermediate position between the pair of mirrors, and the first optical system causes the signal light to be incident on one of the pair of mirrors in the second direction.

[0139] This technology allows for a greater tolerance to the positional misalignment of the second optical system relative to the first optical system in the first direction.

[0140] (Technology 8) An optical connection system according to any one of Technology 1 to 7, characterized in that it is equipped with a positioning mechanism for positioning the second base member relative to the first base member by overlapping the second base member with the first base member.

[0141] According to this technology, the second base member can be positioned relative to the first base member by overlapping it with the first base member. Therefore, the installation work of the second base member relative to the first base member can be simplified.

[0142] (Technical 9) An optical connector comprising an optical connection system described in any one of Technical 1 to 8, and the first base member.

[0143] This technology achieves the same effects as the optical connection system described above.

[0144] (Technical 10) An optical connector as described in Technical 9, further comprising a fixing mechanism for fixing the second base member to the first base member while suppressing displacement of the second base member in a direction away from the first base member.

[0145] This technology allows the second base member (second optical system) to be fixed to the first base member while suppressing misalignment of the second base member in the Z-axis direction.

[0146] 1 Optical connection system 2 Optical connector 3 Fixing mechanism 10 First base member 13, 14 Inclined surface (positioning mechanism) 20 Second base member 23, 24 Inclined surface (positioning mechanism) 30 Optical waveguide 32 Polymer optical waveguide (optical waveguide) 40 Optical fiber 101 First mirror (first optical system) 102 First lens (first optical system) 103 Concave mirror (first optical system) 201 Second mirror (second optical system) 202 Second lens (second optical system) 211, 212 Pair of mirrors (second optical system) 213 Lens (second optical system) 401 Lens (second optical system) F1 Incident end face P2 Intermediate position S1 First optical system S2 Second optical system

Claims

1. An optical connection system comprising: a first optical system installed on a first base member including an optical waveguide; a second base member superimposed on the first base member and on which an optical fiber is installed; and a second optical system installed on the second base member, wherein the first optical system aligns signal light emitted from the optical waveguide and guides it to the second optical system, and the second optical system focuses the signal light from the first optical system onto the incident end face of the optical fiber.

2. An optical connection system according to claim 1, wherein the first optical system comprises a first mirror that bends the optical path of the signal light emitted from the optical waveguide toward the second base member, and a first lens that aligns the signal light emitted from the optical waveguide.

3. An optical connection system according to claim 2, characterized in that the first mirror and the first lens are integrated.

4. An optical connection system according to claim 1, wherein the first optical system includes a concave mirror that bends the optical path of the signal light emitted from the optical waveguide toward the second base member and rectifies the signal light emitted from the optical waveguide into parallel light.

5. An optical connection system according to claim 1, wherein the second optical system comprises a second mirror that bends the optical path of the signal light incident from the first optical system, and a second lens that focuses the signal light reflected by the second mirror onto the incident end face of the optical fiber.

6. An optical connection system according to claim 5, characterized in that the second mirror and the second lens are integrated.

7. An optical connection system according to claim 1, wherein the second optical system comprises a pair of mirrors facing each other in a first direction, the pair of mirrors each having a concave shape symmetrical to each other, and having an optical effect of reflecting light incident on each of the concave shapes in opposite directions in a second direction perpendicular to the first direction, thereby focusing the light at an intermediate position between the pair of mirrors, and the first optical system causes the signal light to be incident on one of the pair of mirrors in the second direction.

8. An optical connection system according to claim 1, characterized in that it includes a positioning mechanism for positioning the second base member relative to the first base member by overlapping the second base member with the first base member.

9. An optical connector comprising the optical connection system according to any one of claims 1 to 8, and the first base member.

10. An optical connector according to claim 9, further comprising a fixing mechanism for fixing the second base member to the first base member while suppressing displacement of the second base member in a direction away from the first base member.

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