JP2017187683A - Optical wiring structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical wiring structure with which it is possible to reduce variation in transmission loss per route.SOLUTION: An optical wiring structure 1 comprises: n first connection units 11-18 in which m first input/output ports P11-P14 are provided; m second connection units 21-24 in which n second input/output ports P21-P28 are provided; and a planar optical waveguide 3 for optically coupling the first connection units and the second connection units. The planar optical waveguide includes (m×n) paths 31 connecting a p-th first input/output port in each of the first connection units and a second input/output port that corresponds to a p-th second connection unit. In each of the paths 31 of the planar optical waveguide is provided an optical loss area in which a transmission loss is proportionately larger in correspondence to a decrease in the number of intersections 33 with other paths 31. The symbols m, n respectively are integers greater than or equal to 2, and p is an integer in the range 1 to m inclusive.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical wiring structure.

  Examples of the optical wiring that transmits light include an optical fiber and an optical wiring substrate in which an optical waveguide is laid on the substrate. Patent Document 1 below discloses an optical waveguide (planar optical waveguide) having a plurality of cores provided on the same plane and a clad surrounding the cores. This planar optical waveguide is provided with an intersection between cores, and a transmission loss occurs at the intersection.

JP2013-156656A JP 2010-61175 A

  In the planar optical waveguide as described above, the number of intersections may be different for each path. In this case, the transmission loss differs from path to path, and the light output through the planar optical waveguide may vary from path to path.

  An object of this invention is to provide the optical wiring structure which can reduce the dispersion | variation in the transmission loss for every path | route.

  An optical wiring structure according to one aspect of the present invention includes n first connection portions provided with m first input / output ports and m second connections provided with n second input / output ports. A planar optical waveguide that optically couples the connecting portion and the first connecting portion and the second connecting portion, and the planar optical waveguide includes a p-th first input / output port in each of the first connecting portions; The p-th second connection portion has (m × n) paths that connect the corresponding second input / output ports, and each of the paths in the planar optical waveguide has an intersection with another path. An optical loss region having a larger transmission loss is provided as the number of is smaller, m and n are each an integer of 2 or more, and p is an integer of 1 or more and m or less.

  ADVANTAGE OF THE INVENTION According to this invention, the optical wiring structure which can reduce the dispersion | variation in the transmission loss for every path | route can be provided.

FIG. 1 is a schematic configuration diagram showing an optical wiring structure according to the embodiment. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is an enlarged plan view of a region surrounded by a dotted line in FIG. FIG. 4 is an enlarged perspective view of the intersection of FIG. FIG. 5 is an enlarged plan view of a region surrounded by a dashed line in FIG. 6A to 6D are plan views showing various forms of the light loss region in the modified example of the present embodiment. FIG. 7 is a schematic cross-sectional view showing an example of the first input / output port P11. FIG. 8 is a schematic plan view of an example of the first input / output port P11.

[Description of Embodiment of Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.

  In one embodiment of the present invention, n first connection portions provided with m first input / output ports, m second connection portions provided with n second input / output ports, A planar optical waveguide that optically couples the first connection portion and the second connection portion, and the planar optical waveguide includes a p-th first input / output port in each of the first connection portions, and a p-th first optical port. There are (m × n) paths connecting the corresponding second input / output ports at the two connection portions, and each of the paths in the planar optical waveguide has a small number of intersections with other paths. An optical loss structure having a transmission loss that is as large as possible is provided, where m and n are each an integer of 2 or more, and p is an integer of 1 or more and an integer of m or less.

  In this optical connection structure, an optical loss region where the transmission loss of light is increased as the number of intersections is reduced is provided for each path of the planar optical waveguide. For this reason, an optical loss region having a relatively large transmission loss is provided in a route having a small number of intersections, and an optical loss region having a relatively small transmission loss is provided in a route having a large number of intersections. Thus, by providing the optical loss region for each path, it is possible to reduce the variation in transmission loss for each path.

  In addition, at least one dummy intersection may be provided in the light loss region. In this case, the dummy intersection has a transmission loss similar to the intersection. For this reason, a relatively large number of dummy intersections are provided in a route with a small number of intersections, and a relatively small number of dummy intersections are provided in a route with a large number of intersections. Transmission loss can be adjusted. In this way, by adjusting the number of dummy intersections for each path, it is possible to satisfactorily reduce the variation in transmission loss for each path.

  In addition, the total number of intersections and dummy intersections in each route may be equal for each route. In this case, variation in transmission loss for each path can be reduced more favorably.

  Further, at least one wide portion may be provided in the light loss region. In this case, by changing at least one of the length and the width of the wide portion in each path, the transmission loss in the optical loss region for each path can be easily adjusted.

  Further, at least one narrow portion may be provided in the light loss region. In this case, it is possible to easily adjust the transmission loss in the optical loss region for each path by changing at least one of the length and width of the narrow portion in each path.

  The light loss region has a first region and a second region that are continuous with each other, and extends along the length direction of the path and passes through the center in the width direction of the first region; The second axis extending along the length direction of the path and passing through the center in the width direction in the second region may be discontinuous with each other. By providing the first region and the second region such that the first axis and the second axis are discontinuous with each other, transmission loss occurs. This transmission loss tends to increase as the deviation width between the first axis and the second axis in the width direction of the path increases. Therefore, the transmission loss in the optical loss region for each path can be easily adjusted by changing the deviation width between the first axis and the second axis.

  The light loss region may be provided with at least one gap that divides the corresponding path. In this case, the transmission loss in the light loss region for each path can be easily adjusted by changing the length of the gap in each path.

  Moreover, the paths constituting the intersection may be orthogonal to each other. In this case, since crosstalk at the intersection can be reduced, attenuation of light guided through the planar optical waveguide can be suppressed.

  The planar optical waveguide may be a silicon optical waveguide. In this case, for example, a path having a width of 1 μm or less can be easily formed.

[Details of the embodiment of the present invention]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same elements or elements having the same functions, and redundant description is omitted.

  FIG. 1 is a schematic plan view showing an optical wiring structure according to the embodiment. An optical wiring structure 1 shown in FIG. 1 includes an optical waveguide 3 that optically couples a substrate 2, n first connection portions, m second connection portions, and first connection portions and second connection portions. And comprising. m and n are integers of 2 or more, respectively, and in this embodiment, m = 4 and n = 8. For this reason, the optical wiring structure 1 includes eight first connection portions 11 to 18 and four second connection portions 21 to 24, and the optical waveguide 3 includes the first connection portions 11 to 18. The second connection parts 21 to 24 are optically coupled.

  The substrate 2 is a member having a substantially rectangular shape in plan view. The substrate 2 is, for example, a single crystal silicon substrate or a metal substrate. In the following, the direction along the long side direction of the substrate 2 in plan view is defined as a first direction α. In addition, a direction perpendicular to the first direction α in plan view and along the short side direction of the substrate 2 is defined as a second direction β.

  The first connection portions 11 to 18 are input / output portions on one end side of the optical waveguide 3 and are arranged in order along the first direction α. The first connection portion 11 is disposed on the substrate 2 at a position closest to the second connection portion 21. The first connection portion 18 is disposed on the substrate 2 at a position farthest from the second connection portion 21. Each of the first connection portions 11 to 18 is provided with four first input / output ports P11 to P14 that are optically coupled to the optical waveguide 3. The number of first input / output ports included in each of the first connection parts 11 to 18 is equal to the number of second connection parts 21 to 24. In other words, each of the first connection portions 11 to 18 is provided with m first input / output ports. The first input / output ports P11 to P14 are arranged in order along the first direction α in the same manner as the first connection portions 11 to 18.

  The second connection parts 21 to 24 are input / output parts on the other end side of the optical waveguide 3, and are arranged in order along the second direction β. The second connection portion 21 is disposed on the substrate 2 at a position closest to the first connection portion 11. The second connection portion 24 is disposed on the substrate 2 at a position farthest from the first connection portion 11. Each of the second connection portions 21 to 24 is provided with eight second input / output ports P21 to P28 that are optically coupled to the optical waveguide 3. The number of second input / output ports included in each of the second connection parts 21 to 24 is equal to the number of first connection parts 11 to 18. In other words, each of the second connection portions 21 to 24 is provided with n second input / output ports. Note that the second input / output ports P21 to P28 are arranged in order along the second direction β in the same manner as the second connection portions 21 to 24.

  The optical waveguide 3 has a plurality of paths 31 connecting the p-th first input / output port in each of the first connection portions 11 to 18 and the corresponding second input / output port in the p-th second connection portion. ing. Since p is an integer of 1 or more and an integer of m or less, p is an integer of 1 or more and 4 or less. Therefore, for example, when p = 2, the optical waveguide 3 is connected to the second first input / output port in each of the first connection portions 11 to 18 and the second input / output corresponding to the second second connection portion 22. Eight paths 31 are respectively connected to the ports P21 to P28. The number of paths 31 is the total number of first input / output ports P11 to P14 in the first connection units 11 to 18 (or the total number of second input / output ports P21 to P28 in the second connection units 21 to 24). 32. In other words, the optical waveguide 3 has (m × n) paths 31.

  FIG. 2 is a cross-sectional view taken along the line II-II in FIG. As shown in FIG. 2, each path 31 in the optical waveguide 3 is provided immediately above the surface 4a of the interlayer film 4 provided on the substrate 2, and is surrounded by the interlayer film 4 and air. . In the present embodiment, the optical waveguide 3 is an optical waveguide using silicon (silicon optical waveguide), specifically a single crystal silicon optical waveguide. The interlayer film 4 is a silicon oxide film. The refractive index of single crystal silicon is about 3.5, and the refractive index of silicon oxide is about 1.5. For this reason, in this embodiment, there is a difference of about 2 between the optical waveguide 3, the interlayer film 4 surrounding the optical waveguide 3, and the refractive index of air. Therefore, the optical waveguide 3 is a planar optical waveguide having a single crystal silicon optical waveguide as a core, an interlayer film 4 surrounding the single crystal silicon optical waveguide, and air as a cladding, and light guided in the optical waveguide 3 is , Well confined.

  The optical waveguide 3 is formed by patterning a silicon film provided on the interlayer film 4, for example. Thereby, the width W1 of each path | route 31 can be set to 0.1 micrometer-1 micrometer, for example. That is, the optical waveguide 3 having the path 31 having a width of 1 μm or less can be easily formed. Moreover, the thickness T of each path | route 31 can be set to 0.05 micrometer-0.5 micrometer, for example, and the space | interval S of the adjacent path | routes 31 can be set to 1 micrometer-10 micrometers. Thereby, since each path | route 31 can be highly integrated, the optical transmission amount in the optical wiring structure 1 can be increased. The optical waveguide 3 is formed by patterning a thin single crystal silicon film on an SOI substrate (Silicon On Insulator substrate) and removing a part of the silicon film.

  FIG. 3 is an enlarged plan view of a region surrounded by a dotted line in FIG. FIG. 4 is an enlarged perspective view of a part of FIG. As described above, the first connection parts 11 to 18 are arranged in order along the first direction α, and the second connection parts 21 to 24 are arranged in order along the second direction β. For this reason, as shown in FIG. 3, each path 31 is provided with a curved portion 32 that bends from the first direction α toward the second direction. The curvature radius r of the curved portion 32 is preferably set to, for example, 10 μm to 100 μm. When the radius of curvature r is within the above range, the paths 31 can be well integrated. In addition, it is possible to prevent a part of the bending portion 32 from forming an intersecting portion 33 described later, and to reduce crosstalk caused by the bending portion 32. Note that the curvature radius r may be different for each path 31.

  In addition, the first connection portions 11 to 18 are arranged in order along the first direction α, and the second connection portions 21 to 24 are arranged in order along the second direction β, so that FIG. As also shown, an intersection 33 with another route 31 is provided depending on the route 31. When a part of the light guided in the path 31 is guided to another path 31 intersecting at the intersection 33, the light is lost. For this reason, the intersection 33 functions as a light loss part in the path 31. The intersecting portion 33 is provided in an area other than the curved portion 32 in the path 31. Further, as described above, the first direction α and the second direction β are orthogonal to each other. For this reason, the paths 31 forming the intersecting portion 33 are substantially orthogonal to each other.

  The number of intersections 33 in the path 31 is different for each path 31. For example, the path 31 for optically coupling the first input / output port P11 of the first connection unit 11 and the second input / output port P21 of the second connection unit 21, and the first input / output port P14 of the first connection unit 18 and the second The intersection 31 is not provided in the path 31 that optically couples the second input / output port P <b> 28 of the two connection unit 24. On the other hand, the path 31 for optically coupling the first input / output port P14 of the first connection unit 11 and the second input / output port P21 of the second connection unit 24, and the first input / output port P11 of the first connection unit 18 and the second In the path 31 that optically couples with the second input / output port P <b> 28 of the two connection portions 21, 21 intersection portions 33 are provided. The maximum number of intersections 33 in one path 31 in the optical waveguide 3 is (m−1) × (n−1).

  FIG. 5 is an enlarged plan view of a region surrounded by a dashed line in FIG. As shown in FIGS. 1 and 5, a light loss region 41 for losing the intensity of light guided in the route 31 is provided in the region surrounded by the alternate long and short dash line in the route 31. Although not shown, the light loss region 41 can be provided in each path 31. The light loss region 41 is provided in a region other than the curved portion 32 and the intersection portion 33 in each path 31, and the light transmission loss increases as the number of the intersection portions 33 in the path 31 decreases. Therefore, the transmission loss of the optical loss region 41 provided in the path 31 having no intersection 33 is the largest, while the transmission loss of the optical loss region 41 provided in the path 31 having the largest intersection 33 is the smallest. . Note that the transmission loss of the light loss region 41 provided in the path 31 having the most intersections 33 may be zero. That is, the light loss region 41 does not have to be provided in the path 31 having the most intersections 33.

  The optical loss region 41 is provided with at least one dummy intersection 42. The dummy intersection 42 functions as a light loss part in the path 31 like the intersection 33, and is formed by a corresponding path 31 and a dummy path 43 extending so as to intersect the path 31 in plan view. Yes. The light guided in the extending direction is not input to the dummy path 43. For this reason, both ends in the extending direction of the dummy path 43 are not connected to any of the first connection portions 11 to 18 and the second connection portions 21 to 24. In addition, the dummy path 43 is not connected to a path 31 other than the path 31 that forms the dummy intersection 42. The width W2 of the dummy path 43 is the same as the width W1 of the path 31. Further, the length of the dummy path 43 is set so as not to contact the adjacent path 31.

  The number of dummy intersections 42 in the light loss region 41 provided for each path 31 increases as the number of intersections 33 in the path 31 decreases. The total number of intersections 33 and dummy intersections 42 in each of the paths 31 is preferably equal for each path 31.

  According to the optical wiring structure 1 according to the present embodiment described above, the optical waveguide 3 connects the pth first input / output port and the corresponding second input / output port at the pth second connection portion 32. The number of intersections 33 in each path 31 varies. For this reason, in the optical wiring structure 1, an optical loss region 41 in which the transmission loss of light increases as the number of intersections 33 decreases with respect to each path 31 of the optical waveguide 3. As a result, an optical loss region 41 having a large transmission loss is provided in the path 31 having a small number of intersections 33, and an optical loss region 41 having a small transmission loss is provided in the path 31 having a large number of intersections 33. As described above, by providing the optical loss region 41 for each path 31, it is possible to reduce variations in transmission loss for each path 31.

  The light loss region 41 may be provided with at least one dummy intersection 42. In this case, the dummy intersection 42 has a transmission loss like the intersection 33. Therefore, a relatively large number of dummy intersections 42 are provided in the route 31 with a small number of intersections 33, and a relatively small number of dummy intersections 42 are provided in the route 31 with a large number of intersections 33. Thus, the transmission loss in the optical loss region can be adjusted. By adjusting the number of dummy intersections 42 for each path 31 in this way, it is possible to satisfactorily reduce the variation in transmission loss for each path 31.

  Further, the total number of the intersections 33 and the dummy intersections 42 in each of the paths 31 may be equal for each path 31. In this case, variation in transmission loss for each path 31 can be reduced more favorably.

  Further, the paths 31 constituting the intersection 33 may be orthogonal to each other. In this case, since crosstalk at the intersection 33 can be reduced, attenuation of light guided through the optical waveguide 3 can be suppressed.

  6A to 6D are plan views showing various forms of the light loss region in the modified example of the present embodiment. In the light loss region, a light loss portion having a shape different from that of the dummy intersection 42 shown in FIG. 5 may be provided. For example, as shown in FIG. 6A, the wide portion 51 is provided in the light loss region 41A. The wide part 51 includes a main part 51 a having a larger width than the path 31, and connection parts 51 b and 51 c that connect the main part 51 a and the path 31. At least one of the length L1 and the width W3 of the wide portion 51 is different for each path 31. When the light in the path 31 is guided from the connection part 51b side to the connection part 51c side, a part of the light is emitted out of the path 31 through the connection part 51c, for example. Even when such an optical loss region 41A is formed, the transmission loss of the optical loss region 41A is easily adjusted by changing at least one of the length L1 and the width W3 for each path 31.

  In addition, as shown in FIG. 6B, a narrow portion 52 is provided in the light loss region 41B. The narrow portion 52 includes a main portion 52 a having a smaller width than the path 31 and connection portions 52 b and 52 c that connect the main portion 52 a and the path 31. At least one of the length L2 and the width W4 of the narrow portion 52 is different for each path 31. When the light in the path 31 is guided from the connection part 52b side toward the connection part 52c side, a part of the light is emitted to the outside of the path 31 through the connection parts 52b and 52c, for example. Even when such an optical loss region 41B is formed, the transmission loss of the optical loss region 41B is easily adjusted by changing at least one of the length L2 and the width W4 for each path 31. .

  Further, as shown in FIG. 6C, the light loss region 41C has a first region 53a and a second region 53b that are continuous with each other. In addition, the first axis C1 extends along the length direction of the path 31 and passes through the center in the width direction of the first region 53a, and extends along the length direction of the path 31 and in the second region 53b. The second axis C2 passing through the center in the width direction is discontinuous with each other. For this reason, in plan view, both sides along the length direction in the first region 53a and both sides along the length direction in the second region 53b are discontinuous. In this case, light guided in the path 31 is emitted out of the path 31 from a portion where a step is formed by the first region 53a and the second region 53b in a plan view, for example. Here, as the deviation width D between the first axis C <b> 1 and the second axis C <b> 2 in the width direction increases, the light guided in the path 31 tends to be easily emitted outside the path 31. In other words, the transmission loss in the light loss region 41C tends to increase as the deviation width D between the first axis C1 and the second axis C2 increases. Therefore, the transmission loss of the light loss region 41C for each path 31 is easily adjusted by changing the deviation width between the first axis C1 and the second axis C2. In addition, the correlation coefficient between the shift width D and the transmission loss is large. For this reason, the transmission loss of the optical loss region 41C for each path 31 can be accurately adjusted by the change in the deviation width D.

  Further, as shown in FIG. 6D, a gap 54 that divides the path 31 is provided in the light loss region 41D. The length L3 of the gap 54 is different for each path 31. A part of the light guided in one path 31 is not input to the other path 31 due to refraction at the interface between the gap 54 and the path 31 and is emitted to the outside of the path 31. Alternatively, part of the light is reflected at the interface between the air gap 54 and the path 31 and is emitted outside the path 31. Even when such an optical loss region 41D is formed, the transmission loss of the optical loss region 41D can be easily adjusted by changing the length L3 for each path 31.

  Next, a structural example of the first input / output port P11 in the first connection unit 11 will be described with reference to FIGS. FIG. 7 is a schematic cross-sectional view showing the first input / output port P11. FIG. 8 is a schematic plan view of the first input / output port P11. As shown in FIGS. 7 and 8, the first input / output port P <b> 11 has a grating coupler structure including a diffraction grating 61 provided on the surface 4 a of the interlayer film 4. The grating coupler structure is a structure that diffracts input light and changes its waveguide direction. The diffraction grating 61 extends so as to have a substantially fan shape in plan view in order to improve the light diffraction efficiency. Specifically, the diffraction grating 61 is formed so that the slits spread concentrically as the distance from the path 31 increases. Similar to the optical waveguide 3, the diffraction grating 61 is formed by patterning a silicon film.

  As shown in FIG. 7, the first input / output port P11 is optically coupled to an external device, and an optical fiber 71 having a core 72 and a clad 73 is bonded via a translucent adhesive A. Yes. Therefore, for example, the light output from the path 31 optically coupled to the first input / output port P11 is diffracted by each diffraction grating 61, and a part of the diffracted light is directed upward. The other part of the diffracted light is directed downward, reflected by the surface 2a of the substrate 2, and directed upward. The light directed upward is input to the core 72 of the optical fiber 71, whereby optical communication between the optical wiring structure 1 and the external device is achieved. The surface 71 a on the substrate 2 side of the optical fiber 71 is inclined at a predetermined angle with respect to the axis of the optical fiber 71 in order to receive light diffracted by the diffraction grating 61 satisfactorily. This predetermined angle is determined by the diffraction angle of the light diffracted by the diffraction grating 61.

  The first input / output ports other than the first input / output port P11 of the first connection unit 11 may have the grating coupler structure. In addition, the second input / output ports P21 to P28 of the second connection portions 21 to 24 may also have the grating coupler structure.

  The optical wiring structure according to the present invention is not limited to the above-described embodiments and modifications, and various other modifications are possible. For example, in the above embodiment, the number of light loss regions 41 provided in the path 31 is not limited, and a plurality of light loss regions 41 may be provided for one path 31.

  Moreover, you may combine the said embodiment and modification suitably. For example, when a plurality of light loss regions are provided in the predetermined path 31, the light loss region 41 provided with the dummy intersection 42 shown in FIG. 5 and the light provided with the wide portion 51 shown in FIG. Both the loss region 41A may be provided.

  In the embodiment and the modification, the optical waveguide 3 may be a planar optical waveguide formed of, for example, quartz. When the optical waveguide is formed using quartz or the like, it is preferable to adjust the distance between the paths so that a part of the curved portion does not form an intersection. This is because a part of the curved portion constitutes an intersection, so that the intersection angle between the paths forming the intersection is reduced, and the occurrence of crosstalk is suppressed.

  Moreover, in the said embodiment and the said modification, the surface 2a of the board | substrate 2 may have shapes (for example, square shape, polygonal shape, circular shape, or ellipse shape) other than substantially rectangular shape.

  Moreover, in the said embodiment and the said modification, the 1st connection parts 11-18 do not need to be arranged along the 1st direction (alpha), and the 2nd connection parts 21-24 are along the 2nd direction (beta). Need not be arranged. Alternatively, the first connection portions 11 to 18 and the second connection portions 21 to 24 may face each other in the first direction α or the second direction β, for example.

  DESCRIPTION OF SYMBOLS 1 ... Optical wiring structure, 2 ... Board | substrate, 3 ... Optical waveguide, 4 ... Interlayer film, 11-18 ... 1st connection part, 21-24 ... 2nd connection part, 31 ... Path | route, 32 ... Curved part, 33 ... Intersection 41, 41A to 41D ... light loss region, 42 ... dummy intersection, 43 ... dummy path, 51 ... wide portion, 52 ... narrow portion, 53a ... first region, 53b ... second region, 54 ... air gap, 61 ... diffraction grating, 71 ... optical fiber, P11 to P14 ... first input / output port, P21 to P28 ... second input / output port, C1 ... first axis, C2 ... second axis, r ... radius of curvature, α ... first One direction, β ... second direction.

Claims (9)

n first connection portions provided with m first input / output ports;
m second connection parts provided with n second input / output ports;
A planar optical waveguide for optically coupling the first connection portion and the second connection portion;
With
The planar optical waveguide connects the p-th first input / output port in each of the first connection portions and the corresponding second input-output port in the p-th second connection portion (m × n). ) Has a book route,
Each of the paths in the planar optical waveguide is provided with a light loss region having a larger transmission loss as the number of intersections with the other paths is smaller.
m and n are each an integer of 2 or more,
p is an integer of 1 or more and m or less,
Optical wiring structure.   The optical wiring structure according to claim 1, wherein at least one dummy intersection is provided in the light loss region.   The optical wiring structure according to claim 2, wherein the total number of the intersections and the dummy intersections in each of the paths is equal for each of the paths.   The optical wiring structure according to claim 1, wherein at least one wide portion is provided in the optical loss region.   The optical wiring structure according to claim 1, wherein at least one narrow portion is provided in the light loss region. The light loss region has a first region and a second region continuous with each other,
A first axis extending along the length direction of the path and passing through a center in the width direction of the first area, and extending along the length direction of the path and extending in the width direction of the second area. The optical wiring structure according to claim 1, wherein the second axis passing through the center is discontinuous with each other.   The optical wiring structure according to claim 1, wherein the optical loss region is provided with at least one air gap that divides the corresponding path.   The optical wiring structure according to claim 1, wherein the paths constituting the intersecting portion are orthogonal to each other.   The optical wiring structure according to claim 1, wherein the planar optical waveguide is a silicon optical waveguide.

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