Optical component

Abstract

To provide an optical component that makes it possible to simplify the alignment between a light path and a meta-lens.SOLUTION: An optical component 11 is formed from a light-transmissive material, and includes: a first plane 14a that is received by a plane 13a which defines an entrance / exit end for each light path having mutually parallel optical axes 15; and a second plane 14b that is parallel to the first plane 14a and on which a meta-lens 16 is established for each optical axis 15.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical component having a first plane received on a plane that defines an optical input / output end, and a second plane parallel to the first plane and establishing a metalens. [Background technology]

[0002] For example, Non-Patent Document 3 discloses a metalens coupled to the cladding of an optical fiber. To form the metalens, a circular substrate is affixed to the end face of the cladding. The substrate has a first plane that overlaps the end face of the cladding and a second plane that is parallel to the first plane and holds the metalens. Light emitted from the end face of the core expands in diameter within the substrate. Because the metalens is formed on the expanded spot, the metalens does not need to be as fine as when the metalens is formed on a spot formed on the end face of the core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7371286 [Non-patent literature]

[0004] [Non-Patent Document 1] A. Arbabi et al, “Subwavelength-thick lenses with high numerical apertures and large efficiency based on high-contrast transmit arrays”, NATURE COMMUNICATIONS 6, Article Number:7069 (2015) [Non-patent document 2] Q. Zhao et al, “Optical Fiber-Integrated Metasurfaces: An Emerging Platform for Multiple Optical Applications”, Nanomaterials 2022, 12(5), 793 [Non-patent document 3] H. Ye et al, “Theoretical realization of single-mode fiber integrated metalens for beam collimating”, Optics Express, Vol.29, Issue 17, (2021), pp27521-27529 Summary of the Invention [Problem to be solved by the invention]

[0005] When coupling a metalens, the metalens is aligned with the core of the optical fiber, so that the optical axis of the metalens is aligned with the optical axis of the core. However, because the cladding diameter is so minute (125 μm), it is not easy to hold the substrate alone. It is also not easy to cut out a disk of the substrate for each individual optical fiber.

[0006] An object of the present invention is to provide an optical component that can simplify the alignment of a light path and a metalens. [Means for solving the problem]

[0007] An optical component according to one aspect of the present invention includes a first plane formed from an optically transparent material and received on a plane that defines an input / output end for each light path having mutually parallel optical axes, and a second plane that is parallel to the first plane and establishes a metalens for each of the optical axes. [Effects of the Invention]

[0008] As described above, according to the disclosed embodiments, an optical component can be provided that can simplify the alignment of the light path and the metalens. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a conceptual diagram schematically illustrating the configuration of an optical component according to a first embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. 1 is a conceptual diagram illustrating the propagation of light according to one embodiment. [Figure 5] FIG. 10 is a conceptual diagram illustrating light propagation according to another embodiment. [Figure 6] FIG. 1 is a conceptual diagram showing an array of metalenses formed on a fused silica substrate. [Figure 7] FIG. 10 is a conceptual diagram showing one step of joining an intermediate part to a holding body. [Figure 8] FIG. 10 is a conceptual diagram showing one step of joining an intermediate part to a holding body. [Figure 9] FIG. 1 is a conceptual diagram showing one step of the alignment method. [Figure 10] FIG. 1 is a conceptual diagram showing one step of the alignment method. [Figure 11] FIG. 10 is a conceptual diagram showing one step of joining an intermediate part to a holding body. [Figure 12] FIG. 4 is a conceptual diagram schematically illustrating the configuration of an optical component according to a second embodiment of the present invention. [Figure 13] FIG. 10 is a conceptual diagram schematically illustrating the configuration of an optical component according to a third embodiment of the present invention. [Figure 14] FIG. [Figure 15] FIG. 10 is a conceptual diagram schematically illustrating the configuration of an optical component according to a fourth embodiment of the present invention. [Figure 16] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0011] FIG. 1 schematically illustrates the configuration of an optical component 11 according to a first embodiment of the present invention. The optical component 11 includes a holder 13 that holds multiple (two or more) optical fibers 12, and an intermediate component 14 that is fixed to the holder 13. The intermediate component 14 has a first flat surface 14a that is received on an end face (flat surface) 13a of the holder 13, and a second flat surface 14b that is parallel to the first flat surface 14a and establishes a metalens 16 for each optical axis 15. The first flat surface 14a is bonded to the end face 13a of the holder 13. The intermediate component 14 is made of an optically transparent material, such as quartz glass or silicon. The holder 13 and the intermediate component 14 may be formed with a first reference surface 17a that is continuously aligned with each other on the holder 13 and the intermediate component 14, and a second reference surface 17b that is perpendicular to the first reference surface 17a and continuously aligned with each other on the holder 13 and the intermediate component 14.

[0012] As shown in FIG. 2, the intermediate component 14 includes a collection of pillars 22 formed on the surface of a transparent substrate 21. A metalens 16 is established by a collection of pillars 22 for each individual optical axis 15. The metalenses 16 can be arranged in a single row or in an array of multiple rows on the second plane 14b. The individual pillars 22 are formed as structures whose size is sufficiently smaller than the wavelength of light. Because such structures are formed using a microfabrication device such as electron beam lithography, the optical axis 15 for each individual metalens 16 can be positioned with high precision. All of the pillars 22 can be embedded in the second plane 14b.

[0013] As shown in FIG. 3 , the holder 13 includes a substrate 24 having a V-groove 23 that crosses the end face 13 a and extends across its surface, and a retaining plate 25 that is overlaid on the surface of the substrate 24 and blocks the V-groove 23. The retaining plate 25 is fixed to the substrate 24, for example, by adhesive. The optical fiber 12 is received in the V-groove 23. The optical fiber 12 includes a core 12 b surrounded by a cladding 12 a that defines a light path, and a resin coating 12 c that covers and protects the cladding 12 a. The resin coating 12 c of the optical fiber 12 terminates at the midpoint in the linear direction of the V-groove 23. Between the end face 13 a and the midpoint, the cladding 12 a is held in the V-groove 23 by the retaining plate 25. The tips of the cladding 12 a and core 12 b are exposed at the end face 13 a of the holder 13. The tip of the core 12 b forms the input and output ends of the light path. Because ultrafine processing technology is used to form the V-groove 23, the V-groove 23 can position the optical axis 15 of the core 12b with high precision. The optical axis 15 of the core 12b and the optical axis 15 of the metalens 16 coincide with each other for each light path.

[0014] Next, the operation of the optical component 11 will be described. For example, a single-mode optical fiber 12 is used. The diameter of the cladding 12a is set to 125 μm. The diameter of the core 12b is set to 9 to 10 μm. A spot of 9 to 10 μm is formed on the end face 13a of the holder 13. As shown in FIG. 4, when the thickness d of the transparent substrate 21 is matched to the focal length f of the metalens 16, the metalens 16 can function as a collimator lens. Light emitted from the input / output end of the optical fiber 12 propagates through the transparent substrate 21 while expanding in diameter. Parallel light is emitted from the metalens 16. Conversely, parallel light incident on the metalens 16 converges toward the input / output end of the optical fiber 12. The light enters the optical fiber 12 smoothly. In the intermediate part 14, the light spot on the second plane 14b can be enlarged in diameter compared to the light spot on the first plane 14a, so that the miniaturization of the metalens 16 can be effectively relaxed.

[0015] As shown in FIG. 5, the metalens 16 can function as a focusing lens. Here, the thickness d of the transparent substrate 21 can be set to match the focal position f2. Light emitted from the input / output end of the optical fiber 12 propagates through the transparent substrate 21 while expanding in diameter. Convergent light exits the metalens 16. Conversely, divergent light incident on the metalens 16 converges toward the input / output end of the optical fiber 12. The light enters the optical fiber 12 smoothly. In the intermediate component 14, the light spot on the second plane 14b can be expanded in diameter compared to the light spot on the first plane 14a, allowing the miniaturization of the metalens 16 to be easily facilitated.

[0016] Next, a method for manufacturing the optical component 11 will be described. As shown in FIG. 6, for example, a quartz glass substrate 26 is prepared. A silicon thin film with a thickness of 1.0 μm is formed on the surface of the substrate 26. A metalens 16 is formed from the silicon thin film. A collection of pillars 22 is machined out for each individual metalens 16. Electron beam lithography or other ultrafine processing techniques are used to form the pillars 22. The optical axis 15 of the metalens 16 can be positioned with high precision.

[0017] Thereafter, the intermediate component 14 including the plurality of metalenses 16 is cut out from the substrate 26. During the cutting process, vertical cutting lines 27a and horizontal cutting lines 27b can be set using, for example, a high-precision dicing device. The vertical cutting lines 27a are set parallel to each other. The horizontal cutting lines 27b are set parallel to each other.

[0018] As shown in FIG. 7 , the optical fiber 12 is coupled to the cut-out intermediate piece 14. To couple, the optical fiber 12 is incorporated into the holder 13. The optical axis of the optical fiber 12 is aligned with the optical axis 15 of the corresponding metalens 16. To align (align), the intermediate piece 14 is held by a fixed base 31. The holder 13 is held by a precision micro-motion table 32. The end face 13a of the holder 13 faces the first flat surface 14a of the intermediate piece 14. The second flat surface 14b of the intermediate piece 14 faces a light receiver 33. The light receiver 33 detects the intensity of the light emitted from the second flat surface 14b. Light L emitted from the input / output end of the core 12b is introduced into the optical fiber 12. When the optical axis 15 of the metalens 16 is aligned with the optical axis 15 of the core 12b, the intensity of the light L received by the light receiver 33 is maximized.

[0019] As shown in FIG. 8, adhesive 34 is applied between the end face 13a of the holder 13 and the first flat surface 14a of the intermediate part 14. It is sufficient to fill the gaps. The intensity maximization is detected in one optical fiber 12 in response to the displacement of the precision micro-adjustment table 32. To detect the maximization, as shown in FIG. 9, the precision micro-adjustment table 32 is linearly driven in the x-axis direction and the y-axis direction relative to the fixed table 31. Next, the intensity maximization is detected in the second optical fiber 12. At this time, as shown in FIG. 10, the precision micro-adjustment table 32 is driven around the optical axis 15 of the maximized optical fiber 12. The first optical fiber 12 is maintained at the maximized intensity.

[0020] Once the two optical fibers 12 have been maximized in strength, the precision micromotion stage 32 presses the holder 13 against the intermediate part 14, as shown in Figure 11. The thickness of the adhesive (layer) 34 is minimized (or optimized) in response to the pressing. The adhesive 34 is then cured. If it is a UV-curable adhesive, the adhesive 34 is irradiated with UV light.

[0021] When the first flat surface 14a is superimposed on the end face 13a and aligned in the in-plane direction of the end face 13a, a metalens 16 can be established for each path of the light L. Metalenses 16 can be established individually for multiple optical fibers 12. Because the optical component 11 only needs to be moved in the in-plane direction of the end face 13a to align the optical axis of the metalens 16, the alignment between the cores 12b of the optical fibers 12 and the metalens 16 can be simplified. Since the alignment only needs to be performed for two optical fibers 12, regardless of the number of optical fibers 12, efficient alignment can be achieved. Furthermore, if the optical axis of the cores 12b and the optical axis 15 of the metalens 16 are accurately aligned with the first reference surface 17a and the second reference surface 17b, the alignment can be completed simply by aligning the first reference surface 17a and the second reference surface 17b. Even more efficient alignment can be achieved.

[0022] FIG. 12 shows a schematic configuration of an optical component 41 according to a second embodiment of the present invention. The optical component 41 comprises an optical circuit board 43 having a plurality (two or more) of optical waveguides 42. The intermediate component 14 described above is fixed to the optical circuit board 43. The first plane 14a of the intermediate component 14 is bonded to an end face (flat face) 43a of the optical circuit board 43. The optical circuit board 43 comprises a substrate body 45 and a clad layer 46 laminated on the surface of the substrate body 45. A core is embedded in the clad layer 46. The core is surrounded by the clad layer 46 and defines a light path. The core functions as an optical waveguide 42. The tip of the core is exposed at the end face 43a of the optical circuit board 43. The tip of the core forms the input / output end of the light path.

[0023] Here, an auxiliary block 47 is fixed to the optical circuit board 43. The auxiliary block 47 is overlaid on the surface of the cladding layer 46. The auxiliary block 47 has a flat surface 47a that is flush with the end surface (flat surface) of the substrate body 45. The first flat surface 14a of the intermediate component 14 is received by the flat surface 47a of the auxiliary block 47 and the end surface of the substrate body 45, so the bonding area of ​​the intermediate component 14 can be increased. The bonding strength of the intermediate component 14 can be increased. The fixation of the intermediate component 14 is stabilized. The optical axis 15 of the metalens 16 is aligned with the optical axis of the corresponding optical waveguide 42.

[0024] The metalens 16 can function as a collimator lens. Light emitted from the input / output end of the optical waveguide 42 propagates through the transparent substrate 21 while expanding in diameter. Parallel light is emitted from the metalens 16. Conversely, parallel light incident on the metalens 16 converges toward the input / output end of the optical waveguide 42. The light enters the optical waveguide 42 efficiently. In the intermediate component 14, the light spot on the second plane 14b can expand in diameter compared to the light spot on the first plane 14a, so the miniaturization of the metalens 16 can be effectively relaxed.

[0025] The metalens 16 can function as a condensing lens. Here, the thickness d of the transparent substrate 21 can be set to match the focal position f2. Light emitted from the input / output end of the optical waveguide 42 propagates through the transparent substrate 21 while expanding in diameter. Convergent light exits the metalens 16. Conversely, divergent light incident on the metalens 16 converges toward the input / output end of the optical waveguide 42. The light enters the optical waveguide 42 efficiently. In the intermediate component 14, the light spot on the second plane 14b can be expanded in diameter compared to the light spot on the first plane 14a, so the miniaturization of the metalens 16 can be effectively relaxed.

[0026] When the first flat surface 14a is overlaid on the end face 43a and aligned in the in-plane direction of the end face 43a, the metalens 16 can be established for each optical path. Metalenses 16 can be established individually for multiple optical waveguides 42. Aligning the optical axis of the metalens 16 requires only moving the optical component 41 in the in-plane direction of the end face 43a, simplifying the alignment between the optical waveguides 42 and the metalens 16. Since alignment of the optical axis of the metalens 16 only requires the alignment of two optical waveguides 42, regardless of the number of optical waveguides 42, efficient alignment can be achieved. Furthermore, if the optical axis of the optical waveguide 42 and the optical axis 15 of the metalens 16 are accurately aligned with the first reference surface 17a and the second reference surface 17b, the alignment can be completed simply by aligning the first reference surface 17a and the second reference surface 17b. Even more efficient alignment can be achieved.

[0027] 13 and 14 schematically show the configuration of an optical component 51 according to a third embodiment of the present invention. The optical component 51 includes an optical multiplexer / demultiplexer 54 including a wavelength filter 53 embedded in a glass block 52. Light of a first wavelength is reflected by the wavelength filter 53. Light of a second wavelength is transmitted through the wavelength filter 53. The glass block 52 has a first light incident / exit surface 55 and a second light incident / exit surface 56 that are set parallel to each other and formed orthogonal to the optical axis of the light that transmits through the wavelength filter 53, and a third light incident / exit surface 57 that is formed orthogonal to the optical axis of the light that enters through the first light incident / exit surface 55 and is reflected by the wavelength filter 53. The third light incident / exit surface 57 is orthogonal to the first light incident / exit surface 55 and the second light incident / exit surface 56.

[0028] The optical component 51 includes a first intermediate component 58 coupled to the first light incident / output surface 55, a second intermediate component 59 coupled to the second light incident / output surface 56, and a third intermediate component 61 coupled to the third light incident / output surface 57. A first holder 62 that holds one or more optical fibers 12 is coupled to the first intermediate component 58. The first intermediate component 58 has a first flat surface 58a that is received on the end face (flat surface) of the first holder 62, and a second flat surface 58b that is parallel to the first flat surface 58a and defines a metalens 63 that functions as a collimator lens. The metalens 63 is embedded in the second flat surface 58b. The second flat surface 58b is formed by the surface of an adhesive layer that bonds the second flat surface 58b to the first light incident / output surface 55. The pillars 22 of the metalens 63 are embedded in the adhesive layer. The first intermediate component 58 and the first holder 62 are configured similarly to the optical component 11 described above.

[0029] A second holding body 64 that holds one or more optical fibers 12 is coupled to the second intermediate component 59. The second intermediate component 59 has a first flat surface 59a that is received on the end face (flat surface) of the second holding body 64, and a second flat surface 59b that is parallel to the first flat surface 59a and establishes a metalens 65 that functions as a collimator lens. The metalens 65 is embedded in the second flat surface 59b. The second flat surface 59b is formed by the surface of an adhesive layer that bonds the second flat surface 59b to the second light input / output surface 56. The pillars 22 of the metalens 65 are embedded in the adhesive layer. The second intermediate component 59 and the second holding body 64 are configured in the same manner as the optical component 11 described above.

[0030] A third holding body 67 that holds one or more optical fibers 12 is coupled to the third intermediate component 61. The third intermediate component 61 has a first flat surface 61a that is received on the end face (flat surface) of the third holding body 67, and a second flat surface 61b that is parallel to the first flat surface 61a and defines a metalens 68 that functions as a collimator lens. The metalens 68 is embedded in the second flat surface 61b. The second flat surface 61b is formed by the surface of an adhesive layer that bonds the second flat surface 61b to the third light input / output surface 57. The pillars 22 of the metalens 68 are embedded in the adhesive layer. The third intermediate component 61 and the third holding body 67 are configured in the same manner as the optical component 11 described above.

[0031] For example, light having a wavelength of 1.3 μm passes through wavelength filter 53. On the other hand, light having a wavelength of 1.55 μm is reflected by wavelength filter 53. Because the collimator lens creates parallel light, divergence of light can be prevented within glass block 52 of optical multiplexer / demultiplexer 54. As a result, light can be transmitted well between metalenses 63, 65, and 68. Because parallel light is formed at second planes 58b, 59b, and 61b, first intermediary component 58, second intermediary component 59, and third intermediary component 61 can function as converters that realize spot expansion and contraction.

[0032] 15 schematically illustrates the configuration of an optical component 71 according to a fourth embodiment of the present invention. The optical component 71 includes a first optical circuit board 73 connected to a first optical transmission line 72, and a second optical circuit board 75 coupled in series to the first optical circuit board 73 and connected to a second optical transmission line 74. The first optical transmission line 72 is formed of an optical fiber 72b connected to the first optical circuit board 73 by an optical connector 72a. Similarly, the second optical transmission line 74 is formed of an optical fiber 74b connected to the second optical circuit board 75 by an optical connector 74a.

[0033] The first optical circuit board 73 is made of a silica glass-based material. The first optical circuit board 73 has one or more optical waveguides 76 exposed at a first end face (flat face) 73a and one or more optical waveguides 77 exposed at a second end face (flat face) 73b. Each optical waveguide 76, 77 can be formed of a cladding layer laminated on the surface of the substrate and a core embedded in the cladding layer. The core defines a path for light. The diameter of the light is set to 9 to 10 μm. The optical connector 72a aligns the optical axis of the optical waveguide 76 with the optical axis of the optical fiber 72b. The optical axes are aligned. Light transmission is achieved between the optical waveguide 76 and the core of the optical fiber 72b.

[0034] The second optical circuit substrate 75 is made of silicon. The second optical circuit substrate 75 has one or more optical waveguides 78 exposed at a first end face (flat surface) 75a and one or more optical waveguides 79 exposed at a second end face (flat surface) 75b. Each optical waveguide 78, 79 can be formed of a clad layer laminated on the surface of the substrate and a core embedded in the clad layer. The core defines a path for the light. The diameter of the light is set to 0.2 to 0.3 μm.

[0035] A first intermediary component 82 and a second intermediary component 83 are coupled to the first end surface 75a and the second end surface 75b of the second optical circuit board 75, respectively. As shown in FIG. 16 , the first intermediary component 82 has a first flat surface 82a that is received on the first end surface 75a of the second optical circuit board 75, and a second flat surface 82b that is parallel to the first flat surface 82a and defines a metalens 84 that functions as a converging lens. The optical axis of the metalens 84 is aligned with the optical axis of the corresponding optical waveguide 78. The metalens 84 is embedded in the second flat surface 82b. The optical axis of the metalens 84 is aligned with the optical axis of the optical waveguide 78. The first intermediary component 82 is configured similarly to the intermediary component 14 described above.

[0036] An adapter 85 is coupled to the second flat surface 82b of the first intermediate component 82. The adapter 85 is formed from an optically transparent material. The adapter 85 has a third flat surface 85a that is received on the second flat surface 82b of the first intermediate component 82, and a fourth flat surface 85b that is parallel to the third flat surface 85a and spaced apart from the third flat surface 85a by a distance that corresponds to the focal length of the metalens 84. The adapter 85 is sandwiched between the second end surface 73b of the first optical circuit board 73 and the second flat surface 82b of the first intermediate component 82. The third flat surface 85a of the adapter 85 is fixed to the second flat surface 82b of the first intermediate component 82 by an adhesive layer 86. The second flat surface 82b is established on the surface of the adhesive layer 86. The pillars 22 of the metalens 84 are embedded in the adhesive layer 86. The fourth flat surface 85b of the adapter 85 is fixed to the second end surface 73b of the first optical circuit board 73 by an adhesive layer 87. The optical axis of the metalens 84 is aligned with the optical axis of the optical waveguide 77.

[0037] The second intermediary component 83 has a first flat surface 83a that is received on the second end surface 75b of the second optical circuit board 75, and a second flat surface 83b that is parallel to the first flat surface 83a and defines a metalens 88 that functions as a converging lens. The optical axis of the metalens 88 is aligned with the optical axis of the corresponding optical waveguide 79. The metalens 88 is embedded in the second flat surface 83b. The second intermediary component 83 is configured similarly to the intermediary component 14 described above.

[0038] An adapter 89 is coupled to the second flat surface 83b of the second intermediate component 83. The adapter 89 is formed from an optically transparent material. The adapter 89 has a third flat surface 89a that is received on the second flat surface 83b of the second intermediate component 83, and a fourth flat surface 89b that is parallel to the third flat surface 89a and spaced apart from the third flat surface 89a by a distance that corresponds to the focal length of the metalens 88. The adapter 89 is sandwiched between the optical connector 74a and the second flat surface 83b of the second intermediate component 83. The third flat surface 89a of the adapter 89 is fixed to the second flat surface 83b of the second intermediate component 83 by an adhesive layer 91. The second flat surface 83b is established on the surface of the adhesive layer 91. The pillars 22 of the metalens 88 are embedded in the adhesive layer 91. The fourth flat surface 89b of the adapter 89 is fixed to the optical connector 74a of the second optical transmission line 74 by an adhesive layer 92. The optical axis of the metalens 88 is aligned with the optical axis of the optical fiber 74b.

[0039] Light emitted from the optical waveguide 77 of the first optical circuit board 73 propagates through the adapter 85 while expanding in diameter. Convergent light is emitted from the metalens 84. The converging light propagates through the transparent substrate 21 of the first intermediate component 82. The light converges toward the optical waveguide 78 of the second optical circuit board 75. The light enters the optical waveguide 78 satisfactorily. Even if the size of the light spot differs between the optical waveguide 77 and the optical waveguide 78, the light can be transmitted satisfactorily from the first optical circuit board 73 to the second optical circuit board 75.

[0040] Light emitted from optical waveguide 78 of second optical circuit board 75 propagates through transparent substrate 21 of first intermediate component 82 while expanding in diameter. Convergent light is emitted from metalens 84. The converging light propagates through adapter 85. The light converges toward optical waveguide 77 of first optical circuit board 73. The light enters optical waveguide 77 smoothly. Even if the size of the light spot differs between optical waveguide 78 and optical waveguide 77, light can be transmitted smoothly from second optical circuit board 75 to first optical circuit board 73.

[0041] The adapter 85 is sandwiched between the second flat surface 82b of the first intermediary component 82 and the second end surface 73b of the first optical circuit board 73. The adapter 85 allows the second end surface 73b of the first optical circuit board 73 to be aligned with the focal position of the metalens 84. The diameter of the light spot on the fourth flat surface 85b can be reduced compared to the light spot on the third flat surface 85a. Furthermore, the size of the light spot can differ between the fourth flat surface 85b of the adapter 85 and the first flat surface 82a of the first intermediary component 82. The combination of the first intermediary component 82 and the adapter 85 can function as a converter that realizes the expansion and contraction of the spot.

[0042] Light emitted from the optical waveguide 79 of the second optical circuit board 75 propagates through the transparent substrate 21 of the second intermediate component 83 while expanding in diameter. Convergent light is emitted from the metalens 88. The convergent light propagates through the adapter 89. The light converges toward the optical fiber 74b of the second optical transmission line 74. The light is smoothly incident on the optical fiber 74b. Even if the size of the light spot differs between the optical waveguide 79 and the optical fiber 74b, the light can be smoothly transmitted from the second optical circuit board 75 to the second optical transmission line 74.

[0043] Light emitted from the optical fiber 74b of the second optical transmission line 74 propagates through the adapter 89 while expanding in diameter. Convergent light is emitted from the metalens 88. The convergent light propagates through the transparent substrate 21 of the second intermediate component 83. The light converges toward the optical waveguide 79 of the second optical circuit board 75. The light enters the optical waveguide 79 smoothly. Even if the size of the light spot differs between the optical fiber 74b and the optical waveguide 79, the light can be transmitted smoothly from the second optical transmission line 74 to the second optical circuit board 75.

[0044] The adapter 89 is sandwiched between the second flat surface 83b of the second intermediary part 83 and the optical connector 74a of the second optical transmission line 74. The adapter 89 allows the optical fiber 74b of the second optical transmission line 74 to be aligned with the focal position of the metalens 88. The diameter of the light spot on the fourth flat surface 89b can be reduced compared to the light spot on the third flat surface 89a. Moreover, the size of the light spot can differ between the fourth flat surface 89b of the adapter 89 and the first flat surface 83a of the second intermediary part 83. The combination of the second intermediary part 83 and the adapter 89 can function as a converter that realizes the expansion and contraction of the spot. [Explanation of symbols]

[0045] 11 Optical Components 12 Optical Fiber 12a Clad 12b Core 13a Plane (end face) 14a 1st plane 14b 2nd plane 15 Optical axis 16 Metalens 23 V groove 24 Substrate 25 Retaining plate 41 Optical Components 42 Core (waveguide) 43a Plane (end face) 45 PCB 46 Cladding layer 63 Metalens 65 Metalens 68 Metalens 75a Plane (1st end surface) 75b Plane (2nd end surface) 82a 1st plane 82b 2nd plane 83a 1st plane 83b 2nd plane 84 Metalens 85 Adapter 85a 3rd plane 85b 4th plane 88 Metalens 89 Adapter 89a 3rd plane 89b 4th plane

Claims

1. formed from a light-transmitting material, a first plane that is received on a plane that defines an input / output end for each light path having a mutually parallel optical axis; a second plane parallel to the first plane and establishing a metalens for each optical axis; and An optical component having:

2. The passage is formed by the core of an optical fiber, which is received in a V-groove defined in a substrate intersecting the plane, and is surrounded by a cladding held in the V-groove by a retaining plate fixed to the substrate. The optical component according to claim 1 .

3. The passage is formed by a core that is embedded in a clad layer laminated on the surface of the substrate and exposed on the flat surface. The optical component according to claim 1 .

4. formed from a light-transmitting material, a third plane received on the second plane; and a fourth plane parallel to the third plane and spaced apart from the third plane by a distance that matches the focal length of the metalens. The optical component according to claim 3 .

5. The metalens is configured as a collimator lens. The optical component according to claim 3 .

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