Optical signal selection device and method for manufacturing optical signal selection device

Abstract

To suppress reduction in coupling efficiency of an optical signal to an output optical fiber.SOLUTION: An optical signal selection device includes: a fiber collimator array in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator which reflects an optical signal emitted from an input optical fiber at a predetermined angle to couple it to an output optical fiber; a wavelength dispersion element which disperses the optical signal by wavelength; and an optical element which is arranged between the wavelength dispersion element and the optical modulator. The optical modulator and the wavelength dispersion element are configured to cause the optical signal to be incident and reflected obliquely with respect to the optical element. When the central position of the plurality of optical fibers in the first direction is defined as the origin, and the distance between the centers of the optical fibers on both ends in the first direction of the plurality of optical fibers is defined as 2w1, at least one of the input optical fibers is provided at a coordinate x in the first direction that satisfies |w1 / 2|≤x≤|w1|.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an optical signal selection device and a method for manufacturing an optical signal selection device. [Background technology]

[0002] High-speed, large-capacity information communication technology using optical wavelength division multiplexing (WDM) is known. Patent Document 1 discloses a technology for controlling the amount of attenuation in the gain equalization operation of a wavelength selection switch using LCOS (Liquid Crystal On Silicon) and a diffraction grating. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-156647 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an optical signal selecting device that uses a fiber collimator array in which multiple optical fibers are arranged at equal intervals, the coupling efficiency between the input port and the output port may decrease depending on the positional relationship between the input port and the output port.

[0005] An object of the present disclosure is to provide an optical signal selection device capable of suppressing a decrease in the coupling efficiency of an optical signal to an output optical fiber, and a method for manufacturing an optical signal selection device. [Means for solving the problem]

[0006] The optical signal selection device of the present disclosure includes a fiber collimator array in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction, an optical modulator that reflects an optical signal outputted from an input optical fiber among the plurality of optical fibers for inputting at a predetermined angle and couples the optical signal to an output optical fiber for outputting, and a wavelength dispersion element that wavelength-disperses the optical signal. the optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflected obliquely relative to the optical element, and at least one of the input optical fibers is provided at a coordinate x in the first direction that satisfies equation (1-1), where the central positions of the plurality of optical fibers in the first direction are set as the origin and the distance between the centers of the optical fibers at both ends of the plurality of optical fibers in the first direction is set as 2w1. |w1 / 2|≦x≦|w1| (1-1)

[0007] The optical signal selection device of the present disclosure includes a fiber collimator array having a plurality of fiber collimator array regions in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction, and an optical modulator that reflects an optical signal outputted from an input optical fiber among the plurality of optical fibers at a predetermined angle and couples the optical signal to an output optical fiber for outputting the optical signal; the optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflected obliquely relative to the optical elements, and in each of the plurality of fiber collimator array regions, when the central positions of the plurality of optical fibers in the first direction are set as the origin and the distance between the centers of the optical fibers at both ends of the plurality of optical fibers in the first direction is set as 2w2, at least one of the input optical fibers is provided at a coordinate x in the first direction that satisfies equation (1-2). |w2 / 2|≦x≦|w2| (1-2)

[0008] The optical signal selection device disclosed herein comprises a fiber collimator array in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction, an optical modulator that reflects an optical signal output from an input optical fiber among the plurality of optical fibers at a predetermined angle and couples it to an output optical fiber for output, a wavelength dispersion element that wavelength disperses the optical signal, and an optical element arranged between the wavelength dispersion element and the optical modulator, wherein the optical modulator and the wavelength dispersion element are configured to input and reflect the optical signal obliquely relative to the optical element, and the plurality of optical fibers are arranged in a curved shape when viewed from the output side of the optical signal.

[0009] The optical signal selection device disclosed herein comprises a fiber collimator array having a plurality of fiber collimator array regions in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction, an optical modulator that reflects an optical signal output from an input optical fiber among the plurality of optical fibers at a predetermined angle and couples it to an output optical fiber for output, a wavelength dispersion element that wavelength disperses the optical signal, and an optical element arranged for each of the fiber collimator array regions between the wavelength dispersion element and the optical modulator, wherein the optical modulator and the wavelength dispersion element are configured to input and reflect the optical signal obliquely with respect to the optical element, and in each of the plurality of fiber collimator array regions, the plurality of optical fibers are arranged in a curved shape when viewed from the output side of the optical signal.

[0010] A manufacturing method for an optical signal selecting device disclosed herein includes a fiber collimator array in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction, an optical modulator that reflects an optical signal output from an input optical fiber among the plurality of optical fibers for input at a predetermined angle and couples it to an output optical fiber for output, a wavelength dispersion element that wavelength disperses the optical signal, and an optical element arranged between the wavelength dispersion element and the optical modulator, and includes configuring the optical modulator and the wavelength dispersion element to input and reflect the optical signal obliquely with respect to the optical element, and locating at least one of the input optical fibers at a coordinate x in the first direction that satisfies equation (1-1), where the central positions of the plurality of optical fibers in the first direction are defined as the origin and the distance between the centers of the optical fibers at both ends of the plurality of optical fibers in the first direction is defined as 2w1. |w1 / 2|≦x≦|w1| (1-1)

[0011] A method for manufacturing an optical signal selection device disclosed herein includes: a fiber collimator array having a plurality of fiber collimator array regions in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator for reflecting an optical signal output from an input optical fiber among the plurality of optical fibers for inputting at a predetermined angle and coupling it to an output optical fiber for outputting; a wavelength dispersion element for wavelength dispersing the optical signal; and a plurality of optical elements arranged for each of the fiber collimator array regions between the wavelength dispersion element and the optical modulator, the optical modulator and the wavelength dispersion element being configured to make the optical signal incident and reflected obliquely with respect to the optical element, and in each of the plurality of fiber collimator array regions, when a central position of the plurality of optical fibers in the first direction is defined as an origin and a distance between the centers of the optical fibers at both ends of the plurality of optical fibers in the first direction is defined as 2w2, at least one of the input optical fibers is provided at a coordinate x in the first direction that satisfies equation (1-2). |w2 / 2|≦x≦|w2| (1-2)

[0012] The manufacturing method of an optical signal selection device disclosed herein includes a fiber collimator array in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction, an optical modulator that reflects an optical signal output from an input optical fiber among the plurality of optical fibers at a predetermined angle and couples it to an output optical fiber for output, a wavelength dispersion element that wavelength disperses the optical signal, and an optical element arranged between the wavelength dispersion element and the optical modulator, the method including configuring the optical modulator and the wavelength dispersion element to input and reflect the optical signal obliquely relative to the optical element, and arranging the plurality of optical fibers in a curved shape when viewed from the output side of the optical signal.

[0013] The manufacturing method of an optical signal selection device disclosed herein includes a fiber collimator array having a plurality of fiber collimator array regions in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction, an optical modulator that reflects an optical signal output from an input optical fiber among the plurality of optical fibers at a predetermined angle and couples it to an output optical fiber for output, a wavelength dispersion element that wavelength disperses the optical signal, and an optical element arranged for each of the fiber collimator array regions between the wavelength dispersion element and the optical modulator, the method including configuring the optical modulator and the wavelength dispersion element to input and reflect the optical signal obliquely with respect to the optical element, and arranging the plurality of optical fibers in a curved shape when viewed from the output side of the optical signal in each of the plurality of fiber collimator array regions. Effect of the Invention

[0014] The present disclosure can suppress a decrease in the coupling efficiency of an optical signal to an output optical fiber. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing the basic configuration of an optical signal selecting device according to the first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating an example of component arrangement of the optical signal selecting device according to the first embodiment. [Diagram 3] FIG. 3 is a diagram for explaining a problem associated with the first embodiment. [Figure 4] FIG. 4 is a diagram for explaining the displacement of the position to which the optical signal returns according to one embodiment. [Diagram 5] FIG. 5 is a diagram for explaining the relationship between the combination of an input optical fiber and an output optical fiber according to a comparative example of the first embodiment and the insertion loss. [Figure 6] FIG. 6 is a diagram for explaining the position at which the input optical fiber according to the first example of the first embodiment is provided. [Figure 7] FIG. 7 is a diagram for explaining the position at which an input optical fiber according to the second example of the first embodiment is provided. [Figure 8] FIG. 8 is a diagram for explaining the relationship between the combination of the input optical fiber and the output optical fiber according to the first embodiment and the insertion loss. [Figure 9] FIG. 9 is a diagram for explaining the position at which an input optical fiber according to the third example of the first embodiment is provided. [Figure 10] FIG. 10 is a diagram for explaining a method for providing a plurality of input optical fibers according to the first embodiment. [Figure 11] FIG. 11 is a diagram showing the principle of the configuration of an optical signal selecting device according to a modified example of the first embodiment. [Figure 12] FIG. 12 is a diagram showing an example of component arrangement of an optical signal selecting device according to a modified example of the first embodiment. [Figure 13] FIG. 13 is a diagram for explaining an overview of an optical signal selecting device according to the second embodiment. [Figure 14] FIG. 14 is a diagram for explaining a method of arranging optical fibers according to the second embodiment. [Figure 15] FIG. 15 is a diagram for explaining the displacement of the return optical signal according to the second embodiment. [Figure 16] FIG. 16 is a diagram for explaining a curved form of a return optical signal according to the second embodiment. [Figure 17] FIG. 17 is a diagram for explaining the displacement of an optical signal at the position of a fiber collimator according to the second embodiment. [Figure 18] FIG. 18 is a diagram for explaining the relationship between the combination of the input optical fiber and the output optical fiber according to the second embodiment and the insertion loss. [Figure 19] FIG. 19 is a diagram for explaining a method for suppressing crosstalk according to the second embodiment. [Figure 20] FIG. 20 is a diagram showing the chief ray of a light beam emitted from an optical fiber. [Figure 21] FIG. 21 is a diagram showing the chief ray of a light beam emitted from an optical fiber. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment, and in the following embodiments, the same components are designated by the same reference numerals, and duplicated explanations will be omitted.

[0017] In the following description, an xyz Cartesian coordinate system is set, and the positional relationship of each part is described with reference to this xyz Cartesian coordinate system. The direction parallel to the x-axis is defined as the x-axis direction, the direction parallel to the y-axis perpendicular to the x-axis is defined as the y-axis direction, and the direction parallel to the z-axis perpendicular to the x-axis and y-axis is defined as the z-axis direction. In addition, a plane including the x-axis and y-axis is appropriately referred to as the xy plane, a plane including the x-axis and z-axis is appropriately referred to as the xz plane, and a plane including the y-axis and z-axis is appropriately referred to as the yz plane.

[0018] [First embodiment] (Optical signal selection device) 1 is a diagram showing the principle configuration of an optical signal selecting device according to the first embodiment. The optical signal selecting device 1 according to the present disclosure is, for example, a free space optics (FSO) type wavelength selective switch (WSS: Wavelength Selective Switch) that uses LCOS (Liquid Crystal On Silicon) for an optical modulator.

[0019] As shown in FIG. 1, the optical signal selecting device 1 includes a fiber collimator array 12, a beam expanding optical system 14, a wavelength dispersion element 16, an optical element 18, and an optical modulator 20.

[0020] The fiber collimator array 12 includes a plurality of optical fibers 10 that input and output optical signals. The optical fibers 10 are provided with lenses at their ends corresponding to the respective optical fibers, and the optical signals output from the respective optical fibers are converted into collimated light or convergent light via the respective lenses. The plurality of optical fibers 10 are arranged, for example, at equal intervals along the x-axis direction. The x-axis direction is also called the first direction. Of the plurality of optical fibers 10, an input optical fiber that outputs an optical signal outputs an optical signal S1 along the z-axis direction toward the beam expansion optical system 14. The input optical fiber that outputs an optical signal is also called an input port.

[0021] The beam expansion optical system 14 expands and shapes the optical signal S1 received from the input optical fiber to a predetermined aspect ratio. The beam expansion optical system 14 outputs the expanded and shaped optical signal S1 to the wavelength dispersion element 16. The beam expansion optical system 14 is composed of, for example, a prism, an optical fiber 10 having positive power, or a lens having negative power. The beam expansion optical system 14 may be composed of, for example, multiple prisms.

[0022] The wavelength dispersion element 16 splits the optical signal S1 received from the beam expansion optical system 14, and outputs the optical signal S1 divided by wavelength. The optical signals S1 of each wavelength are arranged in the direction perpendicular to the paper surface (y-axis direction). The wavelength dispersion element 16 outputs the multiple optical signals S1 divided by wavelength to the optical element 18.

[0023] The optical element 18 shapes the multiple optical signals S1 received from the wavelength dispersion element 16, and outputs the shapes toward the optical modulator 20. The optical element 18 has a curvature in the x-axis direction. The optical element 18 is realized by a single lens, a spherical mirror, or the like.

[0024] FIG. 20 is a diagram showing the chief ray of the light beam emitted from each optical fiber 10 in the optical system extending from the fiber collimator array 12 to the optical modulator 20. In FIG.

[0025] As shown in FIG. 20(a), in the xz plane, the light beam (optical signal S1) emitted from the optical fiber 10 is a parallel light beam up to the optical element 18, but is converted by the optical element 18 into a converging light beam and travels toward the optical modulator 20.

[0026] 20(b), in the yz plane, the light beam (optical signal S1) emitted from the optical fiber 10 is dispersed by the wavelength dispersion element 16. Thereafter, the wavelength-dispersed light beam (optical signal S1) is converted by the optical element 18 into a substantially parallel beam and travels toward the optical modulator 20.

[0027] The optical modulator 20 angle-modulates the optical signal S1 received from the optical element 18 so that the optical signal S1 is coupled to a predetermined output optical fiber among the multiple optical fibers of the fiber collimator array 12. The output optical fiber is also called an output port. The optical modulator 20 is realized by, for example, LCOS. The optical modulator 20 angle-modulates the optical signal S1 and outputs an optical signal S2 to the optical element 18.

[0028] The optical signal S2 travels in the opposite direction to the optical signal S1 through the optical element 18, the wavelength dispersion element 16, the beam expansion optical system 14, and the fiber collimator array 12. The optical signal S2 is reconverted into light having the same beam waist as when it was incident, and is coupled to a predetermined output optical fiber of the fiber collimator array 12.

[0029] The optical modulator 20 is controlled by a control device (not shown). For example, the control device draws, on the optical modulator 20, an astigmatism-correcting phase modulation pattern that acts as a one-dimensional concave lens or convex mirror for eliminating astigmatic difference caused by the optical element 18 of the optical modulator 20. The control device draws, on the optical modulator 20, a diffraction grating pattern for coupling an input optical fiber and an output optical fiber. The control device draws, as the diffraction grating pattern, a blazed diffraction grating pattern for controlling an output beam to a predetermined angle on the optical modulator 20. For example, the control device writes, on the optical modulator 20, an attenuation pattern for suppressing crosstalk that occurs when coupling the paths of an input optical fiber and an output optical fiber.

[0030] Fig. 2 is a diagram showing an example of component arrangement of the optical signal selecting device according to the first embodiment. Fig. 2 shows a perspective view of the optical signal selecting device 1 as seen from above. As shown in Fig. 2, in the first embodiment, the optical signal selecting device 1 has a folded-back structure for miniaturization. In the example shown in Fig. 2, optical signals S1 and S2 are folded back by a wavelength dispersion element 16 and an optical element 18.

[0031] Here, if the number of optical fibers 10 arranged in the fiber collimator array 12 increases (for example, to about 40 or 50), the coupling efficiency between the input optical fiber and the output optical fiber may decrease depending on the positional relationship between the input optical fiber and the output optical fiber.

[0032] FIG. 3 is a diagram for explaining the problem associated with the first embodiment. In the example shown in FIG. 3, the input optical fiber is provided at the origin. For example, when the output optical fiber is provided at the same position as the input optical fiber, the optical signal S1 output from the input optical fiber is modulated by the optical modulator 20 and reaches the position P1 as the optical signal S2-1. In this case, the origin and the position P1 are almost the same position, so there is little decrease in the coupling efficiency. However, when the output optical fiber is provided at a position −5 [mm] away from the origin, the optical signal S1 output from the input optical fiber is modulated by the optical modulator 20 and reaches the position P2 as the optical signal S2-2. In this case, there is a large deviation in the y-axis direction between the position of the output optical fiber and the position P2, so the coupling efficiency decreases. Similarly, when the output optical fiber is provided at a position 5 [mm] away from the origin, the optical signal S1 output from the input optical fiber is modulated by the optical modulator 20 and reaches the position P3 as the optical signal S2-3. In this case, the deviation in the y-axis direction between the position of the output optical fiber and position P3 is large, and therefore the coupling efficiency decreases.

[0033] That is, the displacement of the position where the optical signal returns increases as the distance between the input optical fiber and the output optical fiber increases. The displacement amount differs depending on the position where the optical signal S2 returns, and the curved shape is formed as shown in FIG. 3, because the intersection of the optical signal S2 output from the optical modulator 20 and the optical element 18 is curved. FIG. 4 is a diagram for explaining that the displacement of the position where the optical signal returns according to the first embodiment is caused by the curvature of the intersection of the optical signal S2 and the optical element 18. In the example shown in FIG. 4, the distance from the input optical fiber to the output optical fiber is H, the radius of curvature of the optical element 18 is R, and the angles of the incidence angle 31 and the reflection angle 32 of the optical signal S1 to the optical element 18 are φ. In this case, the displacement amount ΔyS in the y-axis direction of the return position of the optical signal to the optical element 18 at the distance H is correlated with the intersection line between the surface of the optical element 18 and the plane 33 formed by the group of return optical signals from the optical modulator 20. The displacement amount ΔyS is expressed by the following formula (1). ΔyS=R·sinφ·cosφ·-sinφ√(R 2 cos 2 φ-H 2 ) · · · (1)

[0034] As shown in formula (1), the greater the distance H between the input optical fiber and the output optical fiber, the greater the displacement ΔyS. The greater the angle of incidence 31 and the angle of reflection 32, the greater the displacement ΔyS. The smaller the radius of curvature of the optical element 18, the greater the displacement ΔyS.

[0035] Fig. 5 is a diagram for explaining the relationship between the combination of an input optical fiber and an output optical fiber according to a comparative example of the first embodiment and the insertion loss, in which the horizontal axis represents the coordinate of the output optical fiber (output port coordinate) [mm] and the vertical axis represents the insertion loss [dB].

[0036] Graph 101 shows the insertion loss when the input optical fiber is located at 0 [mm] on the x-axis. Graph 102 shows the insertion loss when the input optical fiber is located at 1 [mm] on the x-axis. Graph 103 shows the insertion loss when the input optical fiber is located at 2 [mm] on the x-axis. Graph 104 shows the insertion loss when the input optical fiber is located at 3 [mm] on the x-axis. Graph 105 shows the insertion loss when the input optical fiber is located at 4 [mm] on the x-axis. Graph 106 shows the insertion loss when the input optical fiber is located at 5 [mm] on the x-axis.

[0037] As shown by graphs 101 to 106, when an input optical fiber is provided at X [mm], the insertion loss is small when the output optical fiber is provided at ±X [mm]. In other words, when an input optical fiber is provided at X [mm], the insertion loss increases as the output optical fiber moves away from the position of ±X [mm]. For this reason, in the first embodiment, it is preferable to avoid the center and ends in the x-axis direction as the position at which the input optical fiber is provided. In the first embodiment, the position of the input optical fiber is set so that the insertion loss does not exceed a predetermined value.

[0038] (position of input optical fiber) (First example) The position where the input optical fiber according to the first example of the first embodiment is provided will be described with reference to Fig. 6. Fig. 6 is a diagram for explaining the position where the input optical fiber according to the first example of the first embodiment is provided.

[0039] FIG. 6 shows an example in which only one input optical fiber is provided. As shown in FIG. 6, the fiber collimator array 12 has a plurality of optical fibers 10 arranged at equal intervals along the x-axis direction, for example. The distance between the centers of the optical fibers 10 at both ends of the plurality of optical fibers 10 is assumed to be 2w. In this case, as shown in FIG. 6(a), if the position at which the input optical fiber 10a is provided is x, the input optical fiber 10a is provided at a position where x satisfies "-w≦x≦-w / 2". Alternatively, as shown in FIG. 6(b), the input optical fiber 10a is provided at a position where x satisfies "w / 2≦x≦w". By providing the input optical fiber 10a at these positions, it is possible to suppress a decrease in insertion loss.

[0040] (Second example) The position where the input optical fiber according to the second example of the first embodiment is provided will be described with reference to Fig. 7. Fig. 7 is a diagram for explaining the position where the input optical fiber according to the second example of the first embodiment is provided.

[0041] Fig. 7 shows an example in which two input optical fibers are provided. In the example shown in Fig. 7, the fiber collimator array 12 is provided with two input optical fibers, an input optical fiber 10a-1 and an input optical fiber 10a-2.

[0042] As shown in Fig. 7(a), the input optical fiber 10a-1 is provided at a position where x satisfies "-w≦x≦-w / 2". As shown in Fig. 7(a), the input optical fiber 10a-2 is provided at a position where x satisfies "w / 2≦x≦w". As shown in Fig. 7(a), the input optical fiber 10a-1 and the input optical fiber 10a-2 are provided symmetrically with respect to the origin in the x-axis direction.

[0043] As shown in FIG. 7(b), the input optical fiber 10a-1 is provided at a position where x satisfies "-w≦x≦-w / 2". The position where the input optical fiber 10a-1 in FIG. 7(b) is provided is different from the position where the input optical fiber 10a-1 in FIG. 7(a) is provided. As shown in FIG. 7(b), the input optical fiber 10a-2 is provided at a position where x satisfies "w / 2≦x≦w". The position where the input optical fiber 10a-2 in FIG. 7(b) is provided is different from the position where the input optical fiber 10a-2 in FIG. 7(b) is provided. In FIG. 7(b) as well, the input optical fiber 10a-1 and the input optical fiber 10a-2 are provided symmetrically with respect to the origin in the x-axis direction.

[0044] Fig. 8 is a diagram for explaining the relationship between the combination of the input optical fiber and the output optical fiber according to the first embodiment and the insertion loss. In Fig. 8, the horizontal axis represents the coordinate [mm] of the output optical fiber, and the vertical axis represents the insertion loss [dB].

[0045] In the example shown in Fig. 8, 50 optical fibers 10 are arranged in the fiber collimator array 12 along the x-axis direction. The interval between each optical fiber 10 is, for example, 127 [μm]. In this case, in the example shown in Fig. 7, 25 optical fibers 10 are arranged on the positive side of the x-axis and 25 on the negative side of the x-axis with the origin as the center. The example shown in Fig. 8 shows the relationship between the combination of input optical fibers and output optical fibers and the insertion loss when two input optical fibers are provided among the 50 optical fibers 10.

[0046] Graph 111 shows the insertion loss when the input optical fiber is provided at the center position in the x-axis direction. Graph 112 shows the insertion loss when the first optical fiber 10 on the positive side of the x-axis from the center in the x-axis direction is used as the input optical fiber. Graph 113 shows the insertion loss when the seventh optical fiber 10 on the positive side of the x-axis from the center in the x-axis direction is used as the input optical fiber. Graph 114 shows the insertion loss when the thirteenth optical fiber 10 on the positive side of the x-axis from the center in the x-axis direction is used as the input optical fiber. Graph 115 shows the insertion loss when the nineteenth optical fiber 10 on the positive side of the x-axis from the center in the x-axis direction is used as the input optical fiber. Graph 116 shows the insertion loss when the twentieth optical fiber 10 on the positive side of the x-axis from the center in the x-axis direction is used as the input optical fiber. Graph 117 shows the insertion loss when the twenty-fifth optical fiber 10 on the positive side of the x-axis from the center in the x-axis direction is used as the input optical fiber.

[0047] As shown by graphs 111 to 117, graph 116 has the smallest maximum insertion loss in the entire output port coordinate range, and shows good characteristics. The insertion loss when the 20th optical fiber 10 on the negative side from the center in the x-axis direction is used as the input optical fiber is a profile obtained by flipping graph 116 from left to right due to the symmetry of the optical system in the x-axis direction, and although not shown in FIG. 8, shows good characteristics similar to those of graph 116. In the first embodiment, when the positions of both ends in the positive and negative directions in the x-axis direction from the center of the x-axis of the fiber collimator array 12 are 100%, it is preferable to provide the input optical fiber near the positions 80% in the positive and negative directions from the center of the x-axis. As a result, the first embodiment can obtain good characteristics regardless of the position of the output optical fiber.

[0048] (Third example) The position where the input optical fiber according to the third example of the first embodiment is provided will be described with reference to Fig. 9. Fig. 9 is a diagram for explaining the position where the input optical fiber according to the third example of the first embodiment is provided.

[0049] Fig. 9 shows an example in which three input optical fibers are provided. In the example shown in Fig. 9, the fiber collimator array 12 is provided with three input optical fibers: an input optical fiber 10a-1, an input optical fiber 10a-2, and an input optical fiber 10a-3.

[0050] As shown in Fig. 9(a), the input optical fiber 10a-1 is provided at a position where x satisfies "-w≦x≦-w / 2". As shown in Fig. 9(a), the input optical fiber 10a-2 is provided adjacent to the input optical fiber 10a-1. As shown in Fig. 9(a), the input optical fiber 10a-3 is provided symmetrically with the input optical fiber 10a-2 in the x-axis direction with the origin as the center.

[0051] As shown in Fig. 9(b), the input optical fiber 10a-1 is provided at a position where x satisfies "-w≦x≦-w / 2". As shown in Fig. 9(b), the input optical fiber 10a-3 is provided at a position where x satisfies "w / 2≦x≦w". As shown in Fig. 9(b), the input optical fiber 10a-2 is provided adjacent to the input optical fiber 10a-3. In Fig. 9(b), the input optical fiber 10a-1 and the input optical fiber 10a-3 are provided symmetrically with respect to the origin in the x-axis direction.

[0052] As shown in Fig. 9(c), the input optical fiber 10a-1 is provided at a position where x satisfies "-w≦x≦-w / 2". As shown in Fig. 9(c), the input optical fiber 10a-2 is provided at a position where x satisfies "-w≦x≦-w / 2" and is provided adjacent to the input optical fiber 10a-1. As shown in Fig. 9(c), the input optical fiber 10a-3 is provided at a position where x satisfies "w / 2≦x≦w". In Fig. 9(c), the input optical fiber 10a-2 and the input optical fiber 10a-3 are provided symmetrically with respect to the origin in the x-axis direction.

[0053] That is, in this embodiment, it is preferable that at least one of the input optical fibers is provided at a coordinate x that satisfies formula (2). |w / 2|≦x≦|w| (2)

[0054] A method for providing a plurality of input optical fibers according to the first embodiment will be described with reference to Fig. 10. Fig. 10 is a diagram for explaining a method for providing a plurality of input optical fibers according to the first embodiment.

[0055] As shown in FIG. 10, when a plurality of input optical fibers are provided, the arrows in FIG. 10 arranged in the fiber collimator array 12 represent optical signals. The plurality of optical fibers 10 are classified into a plurality of groups. In the example shown in FIG. 10, two input optical fibers, an input optical fiber 10a-1 and an input optical fiber 10a-2, are provided. In this case, for example, the plurality of optical fibers 10 are classified into two groups, a first group 41 and a second group 42. Specifically, the plurality of optical fibers 10 are classified into two groups, a first group 41 and a second group 42, such that the number of optical fibers 10 included in the first group 41 and the second group 42 is the same.

[0056] The first group 41 includes an input optical fiber 10a-1 and a plurality of output optical fibers 10b-1. The second group 42 includes an input optical fiber 10a-2 and a plurality of output optical fibers 10b-2.

[0057] An optical signal output from the input optical fiber 10a-1 provided in the first group 41 is coupled to one of the multiple output optical fibers 10b-2 provided in the second group 42. An optical signal output from the input optical fiber 10a-2 provided in the second group 42 is coupled to one of the multiple output optical fibers 10b-1 provided in the first group 41.

[0058] The input optical fiber 10a-1 and the input optical fiber 10a-2 are provided at positions symmetrical about the origin in the x-axis direction, and the multiple output optical fibers 10b-1 and the multiple output optical fibers 10b-2 are provided at positions symmetrical about the origin in the x-axis direction.

[0059] By setting the positional relationship between the input optical fiber and the output optical fiber as described above, the light beams emitted from the input optical fiber 10a-1 and the input optical fiber 10a-2 are angle-modulated by the optical modulator 20 at output angles close to specular reflection. In other words, the amount of angle modulation can be made smaller than when the input optical fiber and the output optical fiber are set to be located in the same group. This is therefore a suitable configuration for realizing high efficiency modulation efficiency in the optical modulator 20, and therefore high efficiency optical fiber coupling efficiency.

[0060] In the first embodiment, when a plurality of input optical fibers are provided in the fiber collimator array 12, the input optical fibers can be provided as shown in FIG. 10, thereby making it possible to appropriately couple the paths from the input optical fibers to the output optical fibers.

[0061] [Modification of the first embodiment] An optical signal selecting device according to a modified example of the first embodiment will be described with reference to Fig. 11 and Fig. 12. Fig. 11 is a diagram showing the principle configuration of an optical signal selecting device according to a modified example of the first embodiment. Fig. 12 is a diagram showing an example of component arrangement of an optical signal selecting device according to a modified example of the first embodiment.

[0062] As shown in FIGS. 11 and 12, the optical signal selecting device 1A includes a fiber collimator array 12A, a beam expanding optical system 14, a wavelength dispersion element 16, a first optical element 18-1, a second optical element 18-2, and an optical modulator 20A.

[0063] The fiber collimator array 12A has a plurality of fiber collimator array regions. In the example shown in Fig. 11 and Fig. 12, the fiber collimator array 12A has two fiber collimator array regions, a first fiber collimator array region 12A-1 and a second fiber collimator array region 12A-2.

[0064] In the first fiber collimator array region 12A-1, a plurality of optical fibers 10 are arranged at equal intervals along the x-axis direction. In the second fiber collimator array region 12A-2, a plurality of optical fibers 10 are arranged at equal intervals along the x-axis direction. The optical fibers 10 in the first fiber collimator array region 12A-1 and the second fiber collimator array region 12A-2 are provided with lenses at their ends corresponding to the respective optical fibers, and the optical signals output from the respective optical fibers are converted into collimated light or convergent light through the respective lenses. The number of optical fibers 10 included in the first fiber collimator array region 12A-1 and the second fiber collimator array region 12A-2 is, for example, the same as the number of optical fibers 10 included in the fiber collimator array 12 shown in FIG. 1. That is, the fiber collimator array 12A has a configuration in which a plurality of fiber collimator arrays 12 are connected.

[0065] An input optical fiber of the multiple optical fibers 10 arranged in the first fiber collimator array region 12A-1 outputs an optical signal S11 along the z-axis direction toward the beam expansion optical system 14. An input optical fiber of the multiple optical fibers 10 arranged in the second fiber collimator array region 12A-2 outputs an optical signal S13 along the z-axis direction toward the beam expansion optical system 14.

[0066] The beam expansion optical system 14 expands and shapes the optical signal S11 received from the input optical fiber provided in the first fiber collimator array region 12A-1 to a predetermined aspect ratio. The beam expansion optical system 14 outputs the expanded and shaped optical signal S11 to the wavelength dispersion element 16. The beam expansion optical system 14 expands and shapes the optical signal S13 received from the input optical fiber provided in the second fiber collimator array region 12A-2 to a predetermined aspect ratio. The beam expansion optical system 14 outputs the expanded and shaped optical signal S13 to the wavelength dispersion element 16.

[0067] The wavelength dispersion element 16 splits the optical signal S11 received from the beam expansion optical system 14, separates the optical signal S11 by wavelength, and outputs the split optical signal S11. The optical signals S11 of each wavelength are arranged in the direction perpendicular to the paper surface (y-axis direction). The wavelength dispersion element 16 outputs the multiple optical signals S11 separated by wavelength to the first optical element 18-1.

[0068] The wavelength dispersion element 16 separates the optical signal S13 received from the beam expansion optical system 14, and outputs the optical signal S13 divided by wavelength. The optical signals S11 of each wavelength are arranged by wavelength in the direction perpendicular to the paper surface (y-axis direction). The wavelength dispersion element 16 outputs the multiple optical signals S13 divided by wavelength to the second optical element 18-2.

[0069] The first optical element 18-1 is an optical element disposed relative to the first fiber collimator array region 12A-1. The first optical element 18-1 shapes the multiple optical signals S11 received from the wavelength dispersion element 16, and outputs the shapes toward the first optical modulation region 20A-1 of the optical modulator 20A.

[0070] The second optical element 18-2 is an optical element disposed relative to the second fiber collimator array region 12A-2. The second optical element 18-2 shapes the multiple optical signals S13 received from the wavelength dispersion element 16, and outputs the shapes toward the second optical modulation region 20A-2 of the optical modulator 20A.

[0071] FIG. 21 is a diagram showing the chief rays of the light beams emitted from the respective optical fibers 10 in the optical system extending from the first fiber collimator array area 12A-1 and the second fiber collimator array area 12A-2 to the optical modulator 20. As shown in FIG.

[0072] 21(a), in the xz plane, the light beam (optical signal S11) emitted from the optical fiber 10 of the first fiber collimator array region 12A-1 is a parallel light beam until it reaches the first optical element 18-1, but is converted to a convergent light beam by the first optical element 18-1 and travels toward the first optical modulation region 20A-1. Also, the light beam (optical signal S13) emitted from the optical fiber 10 of the second fiber collimator array region 12A-2 is a parallel light beam until it reaches the second optical element 18-2, but is converted to a convergent light beam by the second optical element 18-2 and travels toward the second optical modulation region 20A-2.

[0073] 21(b), in the yz plane, the light beams (optical signal S11, optical signal S13) emitted from the optical fibers 10 of the first fiber collimator array region 12A-1 and the second fiber collimator array region 12A-2 are dispersed by the wavelength dispersion element 16. Thereafter, the wavelength-dispersed light beams (optical signal S11, optical signal S13) are converted into approximately parallel light beams by the first optical element 18-1 and the second optical element 18-2, and travel toward the optical modulator 20A.

[0074] The first optical modulation region 20A-1 is a region set to modulate the optical signal output from the first fiber collimator array region 12A-1. The second optical modulation region 20A-2 is a region set to modulate the optical signal output from the second fiber collimator array region 12A-2. A control device (not shown) can independently control the first optical modulation region 20A-1 and the second optical modulation region 20A-2.

[0075] The first optical modulation region 20A-1 angle-modulates the optical signal S11 and outputs an optical signal S12 to the first optical element 18-1. The second optical modulation region 20A-2 angle-modulates the optical signal S13 and outputs an optical signal S14 to the second optical element 18-2.

[0076] The optical signal S12 travels in the opposite direction to the optical signal S11 through the first optical element 18-1, the wavelength dispersion element 16, the beam expansion optical system 14, and the first fiber collimator array area 12A-1. The optical signal S12 is reconverted into light having the same beam waist as when it was incident, and is coupled to a predetermined output optical fiber of the first fiber collimator array area 12A-1.

[0077] The optical signal S14 travels in the opposite direction to the optical signal S13 through the second optical element 18-2, the wavelength dispersion element 16, the beam expansion optical system 14, and the second fiber collimator array area 12A-2. The optical signal S14 is reconverted into light having a beam waist equivalent to that at the time of incidence, and is coupled to a predetermined output optical fiber of the second fiber collimator array area 12A-2.

[0078] That is, the optical signal selecting device 1A has a configuration in which a plurality of WSSs are connected in parallel. In the optical signal selecting device 1A, the input optical fiber and the output optical fiber can be appropriately coupled in the same manner as in the optical signal selecting device 1 shown in Fig. 1. For example, in each of the fiber collimator array regions, when the center position of the plurality of optical fibers 10 in the x-axis direction is the origin and the distance between the centers of the optical fibers 10 at both ends of the plurality of optical fibers 10 in the x-axis direction is 2w, it is preferable that at least one of the input optical fibers is provided at a coordinate x that satisfies formula (3). |w / 2|≦x≦|w| (3)

[0079] [Second embodiment] An overview of the optical signal selecting device according to the second embodiment will be described with reference to Fig. 13. Fig. 13 is a diagram for explaining the overview of the optical signal selecting device according to the second embodiment.

[0080] As described above, when the number of optical fibers 10 arranged in the fiber collimator array 12 increases, if the output optical fiber is provided at a position 5 [mm] away from the origin, the optical signal S1 reaches the position P2 as the optical signal S2-2 modulated by the optical modulator 20. Similarly, if the output optical fiber is provided at a position −5 [mm] away from the origin, the optical signal S1 reaches the position P3 as the optical signal S2-3. That is, when the distance between the input optical fiber and the output optical fiber increases, the displacement of the position to which the optical signal returns increases. Therefore, in the second embodiment, in the fiber collimator array 12, the optical fiber 10 at the position 5 [mm] is provided at the position P2, and the optical fiber 10 at the position −5 [mm] is provided at the position P3. That is, in the second embodiment, the multiple optical fibers 10 are arranged in a curved shape when viewed from the output side of the optical signal S1. As a result, the second embodiment can suppress a decrease in the coupling efficiency between the input optical fiber and the output optical fiber.

[0081] (Optical fiber arrangement method) The method for arranging optical fibers according to the second embodiment will be described with reference to Fig. 14. Fig. 14 is a diagram for explaining the method for arranging optical fibers according to the second embodiment.

[0082] For example, as shown in Fig. 14(a), a plurality of optical fibers 10 are arranged on a curve 61 that is convex in the -y-axis direction. For example, as shown in Fig. 14(b), a plurality of optical fibers 10 are arranged on a curve 62 that is convex in the +y-axis direction. Whether to arrange the optical fibers on curve 61 or curve 62 depends on the angle of incidence of the optical signal on the optical element and the configuration of the optical element.

[0083] The displacement of the return optical signal will be described with reference to Fig. 15 and Fig. 16. Fig. 15 is a diagram for explaining the displacement of the return optical signal according to the second embodiment. Fig. 16 is a diagram for explaining the curved form of the return optical signal according to the second embodiment.

[0084] 15, the displacement of the optical signal returning from the optical modulator 20 to the fiber collimator array 12 varies depending on the angle of incidence from the beam expanding optical system 14 to the optical element 18 and the configuration of the beam expanding optical system 14. As described in the explanation of FIG. 4, it also varies depending on the radius of curvature of the optical element 18 and the height (x coordinate) of the intersection point between the optical signal S2 and the optical element 18.

[0085] The angle of incidence from the beam expansion optical system 14 to the optical element 18 varies depending on the position at which the optical modulator 20 is disposed. For example, when an optical signal is reflected from the optical element 18 to the optical modulator 20a, the angle of incidence 71 from the beam expansion optical system 14 to the optical element 18 is positive. For example, when an optical signal is reflected from the optical element 18 to the optical modulator 20b, the angle of incidence 72 from the beam expansion optical system 14 to the optical element 18 is negative.

[0086] 16, the displacement of the optical signal at the position of the optical element 18 changes depending on the angle of incidence of the optical signal from the beam expansion optical system 14 to the optical element 18. When the angle of incidence of the optical signal from the beam expansion optical system 14 to the optical element 18 is positive, the optical signal is displaced in a quadratic curve convex in the -y-axis direction at the position of the optical element 18, as shown by curve 81. When the angle of incidence from the beam expansion optical system 14 to the optical element 18 is negative, the optical signal is displaced in a quadratic curve convex in the +y-axis direction at the position of the optical element 18, as shown by curve 82.

[0087] As shown in Fig. 16, the displacement of the optical signal at the position of the fiber collimator array 12 varies depending on the angle of incidence of the optical signal from the beam expansion optical system 14 to the optical element 18 and the configuration of the beam expansion optical system 14. In the example shown in Fig. 16, the first beam expansion optical system is, for example, a prism or a beam expander including a concave lens and a convex lens. The second beam expansion system is, for example, a beam expander including a convex lens and a convex lens.

[0088] When the angle of incidence of the optical signal from the beam expansion optical system 14 to the optical element 18 is positive and the beam expansion optical system 14 is the first beam expansion optical system, the optical signal is displaced in a convex quadratic curve shape in the -y-axis direction at the position of the fiber collimator array 12, as shown by a curve 83. When the angle of incidence of the optical signal from the beam expansion optical system 14 to the optical element 18 is negative and the beam expansion optical system 14 is the first beam expansion optical system, the optical signal is displaced in a convex quadratic curve shape in the +y-axis direction at the position of the fiber collimator array 12, as shown by a curve 84.

[0089] When the angle of incidence of the optical signal from the beam expansion optical system 14 to the optical element 18 is positive and the beam expansion optical system 14 is the second beam expansion optical system, the optical signal is displaced in a convex quadratic curve shape in the +y-axis direction at the position of the fiber collimator array 12, as shown by a curve 85. When the angle of incidence of the optical signal from the beam expansion optical system 14 to the optical element 18 is negative and the beam expansion optical system 14 is the second beam expansion optical system, the optical signal is displaced in a convex quadratic curve shape in the -y-axis direction at the position of the fiber collimator array 12, as shown by a curve 86.

[0090] As described with reference to Fig. 4, the displacement ΔyS in the y-axis direction of the intersection point between the optical signal S2 and the optical element 18 can be expressed by equation (1). Therefore, if the x-coordinate position of the output optical fiber in Fig. 14 is H, the displacement Δy in the y-axis direction at position H can be expressed by equation (4). Δy(H)∝|R·sinφ·cosφ·-sinφ√(R 2 cos 2 φ-H 2 )|···(4)

[0091] Fig. 17 is a diagram for explaining the displacement of an optical signal at the position of a fiber collimator according to the second embodiment. Fig. 17 is a diagram for explaining the displacement of an optical signal at the position of a fiber collimator according to the second embodiment, and is an example calculated with R=200 [mm] and φ=12.62 [degrees].

[0092] In FIG. 17, the horizontal axis represents the y coordinate [μm] of the return optical signal at the position of the optical fiber 10, and the vertical axis represents the x coordinate [mm] of the return optical signal at the position of the optical fiber 10. A graph 121 represents the calculation result of the xy coordinate of the return optical signal when the input optical fiber is provided at (x, y) = (0, 0). For example, when x = 0 [mm], the displacement amount of the return optical signal is 0 [μm]. For example, when x = ± 1 [mm], the displacement amount of the return optical signal is 1.4 [μm]. For example, when x = ± ± 2 [mm], the displacement amount of the return optical signal is 5.7 [μm]. For example, when x = ± 3 [mm], the displacement amount of the return optical signal is 12.9 [μm]. For example, when x = ± 4 [mm], the displacement amount of the return optical signal is 22.9 [μm]. For example, when x = ± 5 [mm], the displacement amount of the return optical signal is 35.8 [μm]. 17, the graph 121 can be approximated by a quadratic curve. Therefore, in the fiber collimator array 12, by arranging the multiple optical fibers 10 in a quadratic curve convex in the +y-axis direction or the -y-axis direction when viewed from the output side of the optical signal so as to match the displacement amount of the return signal in the graph 121, it is possible to suppress a decrease in the coupling efficiency between the input optical fiber and the output optical fiber.

[0093] Fig. 18 is a diagram for explaining the relationship between the combination of the input optical fiber and the output optical fiber according to the second embodiment and the insertion loss. In Fig. 18, the horizontal axis represents the coordinate [mm] of the output optical fiber, and the vertical axis represents the insertion loss [dB].

[0094] FIG. 18 shows the relationship between the coordinates of the output optical fiber and the insertion loss when a plurality of optical fibers 10 are arranged in a quadratic curve as viewed from the output side in a comparative example to the embodiment shown in FIG.

[0095] Graph 131 represents the insertion loss when the input optical fiber is provided at 0 [mm] on the x-axis. Graph 132 represents the insertion loss when the input optical fiber is provided at 1 [mm] on the x-axis. Graph 133 represents the insertion loss when the input optical fiber is provided at 2 [mm] on the x-axis. Graph 134 represents the insertion loss when the input optical fiber is provided at 3 [mm] on the x-axis. Graph 135 represents the insertion loss when the input optical fiber is provided at 4 [mm] on the x-axis. Graph 136 represents the insertion loss when the input optical fiber is provided at 5 [mm] on the x-axis. That is, graphs 131 to 136 correspond to graphs 101 to 106 shown in FIG. 5, respectively.

[0096] As shown by graphs 131 to 136, the insertion loss can be reduced by arranging the multiple optical fibers 10 in a curved shape when viewed from the output side of the optical signal. In other words, the coupling efficiency between the input optical fiber and the output optical fiber can be improved by arranging the multiple optical fibers 10 in a curved shape when viewed from the output side of the optical signal.

[0097] A method for suppressing crosstalk according to the second embodiment will be described with reference to Fig. 19. Fig. 19 is a diagram for explaining a method for suppressing crosstalk according to the second embodiment.

[0098] As shown in FIG. 19, in the second embodiment, the fiber collimator array 12 has an optical fiber 10-1, an optical fiber 10-2, an optical fiber 10-3, an optical fiber 10-4, and an optical fiber 10-5 arranged in a curved line 61. As shown in FIG.

[0099] When the optical modulator 20 is an LCOS, the modulation surface of the optical modulator 20 has a grid-like structure, and therefore the return optical signal from the optical modulator 20 contains high-order diffracted light in the up, down, left and right directions. Therefore, diffracted light 90-1 is incident on the optical fiber 10-1, diffracted light 90-2 is incident on the optical fiber 10-2, diffracted light 90-3 is incident on the optical fiber 10-3, diffracted light 90-4 is incident on the optical fiber 10-4, and diffracted light 90-5 is incident on the optical fiber 10-5. If each diffracted light is incident on an optical fiber other than the desired optical fiber, the crosstalk performance deteriorates.

[0100] 19, the optical fibers 10-1 to 10-5 are arranged in a curved line 61, so that each diffracted light is unlikely to be incident on an optical fiber other than the desired optical fiber. Therefore, in the second embodiment, crosstalk can be suppressed by arranging each optical fiber in a curved line when viewed from the output side of the optical signal.

[0101] [Modification of the second embodiment] A modification of the second embodiment will be described. In the modification of the second embodiment, even in the optical signal selecting device 1A shown in Fig. 11 and Fig. 12, by arranging the optical fibers 10 in each fiber collimator array region in a quadratic curve shape convex in the +y-axis direction or convex in the -y-axis direction when viewed from the output side of the optical signal, it is possible to suppress a decrease in the coupling efficiency between the input optical fiber and the output optical fiber.

[0102] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the contents of these embodiments. The above-mentioned components include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-mentioned components can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the gist of the above-mentioned embodiments. [Explanation of symbols]

[0103] 1,1A Optical signal selection device 10 Optical Fiber 12,12A Fiber collimator array 12A-1 First fiber collimator array area 12A-2 Second fiber collimator array area 14 Beam expansion optics 16 Wavelength dispersion element 18 Optical Elements 18-1 First optical element 18-2 Second optical element 20,20A Optical Modulator 20A-1 First optical modulation area 20A-2 Second optical modulation area

Claims

1. a fiber collimator array in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator that reflects an optical signal output from an input optical fiber among the plurality of optical fibers at a predetermined angle and couples the optical signal to an output optical fiber; A wavelength dispersion element that wavelength disperses the optical signal; an optical element disposed between the wavelength dispersion element and the optical modulator; Equipped with the optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflected obliquely to the optical element, The center positions of the plurality of optical fibers in the first direction are defined as the origin, and the distance between the centers of the optical fibers at both ends of the plurality of optical fibers in the first direction is defined as 2w １ at least one of the input optical fibers is provided at a coordinate x in the first direction that satisfies formula (1-1). Optical signal selection device. |w １ / 2|≦x≦|w １ |・・・(1-1)

2. When a plurality of the input optical fibers are provided, the optical fibers are classified into two groups, a first group and a second group, so that the numbers of the input optical fibers are as equal as possible, and at least one set of the input optical fibers included in each group are arranged symmetrically with respect to an origin in the first direction; 2. The optical signal selection device according to claim 1.

3. the output optical fibers corresponding to the input optical fibers provided in the first group are provided in the second group; the output optical fiber corresponding to the input optical fiber provided in the second group is provided in the first group; 3. An optical signal selection device according to claim 2.

4. The reflecting surface of the optical element has a curvature in the first direction.

2. The optical signal selection device according to claim 1.

5. a fiber collimator array having a plurality of fiber collimator array regions in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator that reflects an optical signal output from an input optical fiber among the plurality of optical fibers at a predetermined angle and couples the optical signal to an output optical fiber; A wavelength dispersion element that wavelength disperses the optical signal; a plurality of optical elements arranged for each of the fiber collimator array regions between the wavelength dispersion element and the optical modulator; Equipped with the optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflected obliquely to the optical element, In each of the plurality of fiber collimator array regions, the center positions of the plurality of optical fibers in the first direction are defined as the origin, and the distance between the centers of the optical fibers at both ends of the plurality of optical fibers in the first direction is defined as 2w ２ at least one of the input optical fibers is provided at a coordinate x in the first direction that satisfies formula (1-2). Optical signal selection device. |w ２ / 2|≦x≦|w ２ |・・・(1-2)

6. a fiber collimator array in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator that reflects an optical signal output from an input optical fiber among the plurality of optical fibers at a predetermined angle and couples the optical signal to an output optical fiber; A wavelength dispersion element that wavelength disperses the optical signal; an optical element disposed between the wavelength dispersion element and the optical modulator; Equipped with the optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflected obliquely to the optical element, the optical fibers are arranged in a curved shape when viewed from the output side of the optical signal; Optical signal selection device.

7. The reflecting surface of the optical element has a curvature in the first direction.

7. An optical signal selection device according to claim 6.

8. The reflecting surface of the optical element is a spherical surface.

8. An optical signal selection device according to claim 7.

9. a beam expanding system including a plurality of prisms or a lens having a negative power and a lens having a positive power between the fiber collimator array and the wavelength dispersion element; The optical fibers are arranged such that their coordinates in a second direction perpendicular to the first direction are different from each other, the optical fibers are arranged in a quadratic curve convex in a negative direction of the second direction as viewed from an output side of the optical signal, with the central positions of the optical fibers in the first direction being taken as origins; 7. An optical signal selection device according to claim 6.

10. a beam expanding system including a lens having a positive power between the fiber collimator array and the wavelength dispersion element; The optical fibers are arranged such that their coordinates in a second direction perpendicular to the first direction are different from each other, the optical fibers are arranged in a quadratic curve convex in a positive direction of the second direction as viewed from an output side of the optical signal, with the central positions of the optical fibers in the first direction being taken as origins; 7. An optical signal selection device according to claim 6.

11. When a radius of curvature of a reflecting surface of the optical element is R and an incident reflection angle of an optical signal emitted from the origin of the fiber collimator array to the optical element is φ, the optical fibers are disposed at positions where the coordinate y in the second direction satisfies the following formula (1-3):

11. An optical signal selection device according to claim 9 or 10. y∝|R・sinφ・cosφ・-sinφ√(R ２ cos ２ φ-x ２ )|・・・(1-3)

12. a fiber collimator array having a plurality of fiber collimator array regions in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator that reflects an optical signal output from an input optical fiber among the plurality of optical fibers at a predetermined angle and couples the optical signal to an output optical fiber; A wavelength dispersion element that wavelength disperses the optical signal; an optical element disposed for each of the fiber collimator array regions between the wavelength dispersion element and the optical modulator; Equipped with the optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflected obliquely to the optical element, In each of the plurality of fiber collimator array regions, the plurality of optical fibers are arranged in a curved shape as viewed from an output side of the optical signal. Optical signal selection device.

13. A method for manufacturing an optical signal selection device comprising: a fiber collimator array in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator that reflects an optical signal outputted from an input optical fiber among the plurality of optical fibers for inputting at a predetermined angle and couples the optical signal to an output optical fiber for outputting; a wavelength dispersion element that wavelength-disperses the optical signal; and an optical element disposed between the wavelength dispersion element and the optical modulator, The optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflect obliquely with respect to the optical element; The center positions of the plurality of optical fibers in the first direction are defined as the origin, and the distance between the centers of the optical fibers at both ends of the plurality of optical fibers in the first direction is defined as 2w １ at least one of the input optical fibers is provided at a coordinate x in the first direction that satisfies formula (1-1); A method for manufacturing an optical signal selection device, comprising: |w １ / 2|≦x≦|w １ |・・・(1-1)

14. A method for manufacturing an optical signal selection device comprising: a fiber collimator array having a plurality of fiber collimator array regions in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator for reflecting an optical signal outputted from an input optical fiber among the plurality of optical fibers at a predetermined angle and coupling the optical signal to an output optical fiber for output; a wavelength dispersion element for wavelength dispersion of the optical signal; and a plurality of optical elements arranged for each of the fiber collimator array regions between the wavelength dispersion element and the optical modulator, The optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflected obliquely to the optical element; In each of the plurality of fiber collimator array regions, the center positions of the plurality of optical fibers in the first direction are defined as the origin, and the distance between the centers of the optical fibers at both ends of the plurality of optical fibers in the first direction is defined as 2w ２ at least one of the input optical fibers is provided at a coordinate x in the first direction that satisfies formula (1-2); A method for manufacturing an optical signal selection device, comprising: |w ２ / 2|≦x≦|w ２ |・・・(1-2)

15. A method for manufacturing an optical signal selection device comprising: a fiber collimator array in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator that reflects an optical signal outputted from an input optical fiber among the plurality of optical fibers for inputting at a predetermined angle and couples the optical signal to an output optical fiber for outputting; a wavelength dispersion element that wavelength-disperses the optical signal; and an optical element disposed between the wavelength dispersion element and the optical modulator, The optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflected obliquely to the optical element; arranging the optical fibers in a curved shape as viewed from an output side of the optical signal; A method for manufacturing an optical signal selection device, comprising:

16. A method for manufacturing an optical signal selection device comprising: a fiber collimator array having a plurality of fiber collimator array regions in which a plurality of optical fibers for inputting and outputting optical signals are arranged at equal intervals along a first direction; an optical modulator for reflecting an optical signal outputted from an input optical fiber among the plurality of optical fibers at a predetermined angle and coupling the optical signal to an output optical fiber for output; a wavelength dispersion element for wavelength dispersion of the optical signal; and an optical element arranged for each of the fiber collimator array regions between the wavelength dispersion element and the optical modulator, The optical modulator and the wavelength dispersion element are configured to make the optical signal incident and reflected obliquely to the optical element; In each of the plurality of fiber collimator array regions, the plurality of optical fibers are arranged in a curved shape as viewed from an output side of the optical signal; A method for manufacturing an optical signal selection device, comprising:

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