JP6368290B2 - Optical signal processing device - Google Patents

Description

  The present invention relates to an optical signal processing apparatus including a wavelength selective switch used in an optical communication network.

  With the explosive spread of data communication networks such as the Internet, the demand for an increase in the capacity of optical communication networks has become stronger. Although wavelength division multiplexing communication has been put into practical use in order to cope with such an increase in network demand, in recent years, the demand for wavelength selective switches (WSS: Wavelength Selective Switch) that enables path switching for each wavelength is also increasing. . In particular, as the number of routes increases, a route & select type node configuration using wavelength selective switches on both the Add side and the Drop side tends to become mainstream. Therefore, there is a demand for N-in-1_WSS in which a plurality of wavelength selective switches on the Add side and the Drop side are integrated.

  Such a wavelength selective switch uses LCOS (Liquid Crystal on Silicon) as its switching engine. LCOS is a spatial phase modulator using liquid crystal, and can realize a fine and flexible switching function.

  On the other hand, LCOS has a problem that the polarization of the incident light is limited. That is, in general, the incident polarization to the LCOS is required to be a linear polarization along a certain axis. However, in general, in optical communication, the polarization input to the optical switch is not defined, so that polarization diversity is required.

  As a response to the N-in-1_WSS request, in the invention of the wavelength selective switch disclosed in Patent Document 1, a configuration in which light is emitted from the input unit at different angles for each of a plurality of WSSs is shown. Furthermore, it has been shown that a planar lightwave circuit is used as a method for easily realizing this.

  FIG. 6 is a diagram illustrating a configuration example of the wavelength selective switch (see Patent Document 1). In the input optical system 1001, the input / output port groups 1005 and 1006 correspond to different WSSs. When 1005 is selected as the input / output port, the light path of the broken line in the figure is propagated, and when 1006 is selected as the input / output port, the light path of the solid line is propagated. The light is wavelength-separated in the x-axis direction by the diffraction grating 1002 and then condensed on the LCOS 1004 by the main lens 1003. The light is collected at different positions on the y-axis depending on whether the input / output port belongs to 1005 or 1006. Shine. Therefore, switching can be performed independently for each WSS.

  The light is reflected at a predetermined angle for each wavelength by the LCOS 1004, propagates through the main lens 1003 and the diffraction grating 1002 in the reverse order of the forward path, and is coupled to a predetermined port of the input optical system 1001. It is stated that with this configuration, it is possible to achieve simplification and cost reduction of the optical system, such as a single lens, as compared to the conventional 2-in-1_WSS configuration.

  Moreover, as a method of realizing polarization diversity, there are methods disclosed in Patent Documents 2 and 3. In the wavelength selective switch disclosed in Patent Document 2, the polarization diversity configuration is realized by a bulk optical component, whereas in the wavelength selective switch disclosed in Patent Document 3, a polarization diversity function is input. A simple configuration is realized by integrating in a planar optical waveguide constituting the optical system.

  FIG. 7 is a diagram showing another configuration example of a conventional wavelength selective switch (see Patent Document 3). In FIG. 7, an optical signal input from an input unit 1111 to an input optical system 1101 integrated in an optical waveguide is separated into two polarization components orthogonal to each other by a polarization separation means 1201, one of which is a polarization rotation means. 1202 rotates the plane of polarization by 90 °.

  The optical signal having the same plane of polarization is then shaped into a desired beam diameter and emission direction by an SBT (Spatial Beam Transformer) circuit 1203 and output from the input optical system 1101 as two orthogonal polarization components. Is done. The two orthogonal polarization components of each are clearly shown as dotted lines 1109 and 1110.

  The optical signal output from the input optical system 1101 is deflected in a desired direction by the LCOS 1106 via the cylinder lenses 1102, 1103, and 1105 and the diffraction grating 1104, and then passes through the cylinder lenses 1102, 1103, 1105 and the diffraction grating 1104. It propagates in the reverse direction and enters the input optical system 1101. In the input optical system 1101, the SBT circuit 1203 again converts the incident optical signal into the fundamental mode of the isolated waveguide, and after combining the polarization, is output from the output unit 1112.

International Publication No. 2015/008489 Pamphlet US Pat. No. 7,379,980 JP 2014-48411 A Table 2010/140363

K. Seno, K. Suzuki, N. Ooba, T. Watanabe, M. Itoh, T. Sakamoto, T. Takahashi, “Spatial beam transformer for wavelength selective switch consisting of silica-based planar lightwave circuit,” Proceedings of OFC / NFOEC 2012, JTh2A.5

  In the WSS disclosed in Patent Document 1, by using a planar lightwave circuit, it is possible to simplify the optical system of N-in-1_WSS, simplify the removal of alignment work, and the like. However, in the configuration disclosed therein, polarization diversity is abandoned, and in practice, a polarization diversity optical system has to be incorporated separately, so that there is a problem that the optical system is complicated accordingly. .

  On the other hand, in the wavelength selective switch disclosed in Patent Document 3, the polarization diversity optical system is integrated in the optical waveguide as compared with the wavelength selective switch having the polarization diversity optical system using the bulk optical component disclosed in Patent Document 2. Thus, simplification of the system, removal of alignment work, and the like can be achieved. However, even with the configuration disclosed therein, there is a problem that the configuration of N-in-1_WSS required by the market cannot be handled.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an optical signal processing device including N-in-1_WSS in which a polarization diversity optical system is integrated in a waveguide. is there.

  In order to solve the above problems, the present invention provides an optical circuit board having a waveguide formed on a substrate, a polarization control means for controlling a polarization state of light output from the optical circuit board, And an optical signal processing device for reflecting light so as to recombine light output from the optical circuit board to the optical circuit board, wherein the optical circuit board is one first At least two polarization separation circuits for separating light input from the input / output ports into different first and second polarized waves that are orthogonal to each other and outputting them from the two second input / output ports, respectively, and the at least two Light of the same polarization output from the polarization separation circuit is input from a plurality of third input / output ports, and the plurality of input light is output at different angles corresponding to each of the plurality of third input / output ports. At least two light beams An output circuit, wherein the polarization control means controls the polarization of the light output from the light beam input / output circuit to a single polarization for operating the light modulation means. .

  According to a second aspect of the present invention, in the optical signal processing device according to the first aspect, the optical circuit board has M fourth input / output port groups each including N input / output ports as one unit, M polarization separation circuit groups each including N polarization separation circuits as one unit, and two light beam input / output circuits each including N third input / output ports as one unit, M light beam input / output circuit groups are provided, each of the fourth input / output port groups is connected to a first input / output port of each of the polarization separation circuit groups, and each of the polarization separation circuit groups, The N second input / output port groups that output the first polarized wave include N third input / output ports of the first light beam input / output circuit among the light beam input / output circuit groups. N second input / output port groups that are respectively connected to the ports and output the second polarization of each of the polarization separation circuit groups, Of climate beam incidence and emission circuits, respectively connected to the N third output port of the second of the light beam incidence and emission circuit, characterized in that.

  According to a third aspect of the present invention, in the optical signal processing device according to the first or second aspect, the polarization control means includes a first region in which the polarization state is not changed and a second region in which the polarization is rotated by 90 °. The first region and the second region are alternately and repeatedly arranged at the same arrangement interval as the light beam input / output circuit.

  According to a fourth aspect of the present invention, in the optical signal processing device according to any one of the first to third aspects, the polarization control means is provided on a light emitting end face of the optical circuit board on the light beam incident / exit circuit side. It is characterized by being bonded.

  According to a fifth aspect of the present invention, in the optical signal processing device according to any one of the first to fourth aspects, the light beam input / output circuit includes a plurality of input / output terminals respectively connected to the third input / output port. A waveguide, a first slab waveguide in which the plurality of input / output waveguides are connected to one end at different angles, an array waveguide in which one end is connected to the other end of the first slab waveguide, And a second slab waveguide to which the other end of the arrayed waveguide is connected.

  According to a sixth aspect of the present invention, in the optical signal processing device according to any one of the first to fourth aspects, the light beam input / output circuit includes a plurality of input / output terminals respectively connected to the third input / output port. It is characterized by comprising a waveguide and a slab waveguide in which the plurality of input / output waveguides are connected to one end at different angles.

  According to a seventh aspect of the present invention, in the optical signal processing device according to any one of the first to fourth aspects, the light beam input / output circuit includes a plurality of input / output terminals respectively connected to the third input / output port. A slab waveguide in which a waveguide and the plurality of input / output waveguides are parallel and connected to one end, and includes a region having at least two refractive indexes on an optical path of light propagating through the slab waveguide. And a waveguide.

  The present invention enables simplification and simplification of a system by integrating a polarization diversity optical system in a waveguide in an optical signal processing apparatus including N-in-1_WSS.

It is a figure which shows the structure of the optical signal processing apparatus provided with 2-in-1_1xM_WSS which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the relationship between the operation | movement of the optical circuit board 101 in the 1st Embodiment of this invention, the polarization rotation element 102, and each optical path. (A)-(c) is a figure which shows the Example of the light beam incident / exit circuit 205 in this invention. It is a figure which shows the structure of the optical signal processing apparatus provided with 3-in-1_1 * M_WSS which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the relationship between operation | movement of the optical circuit board 101 in the 2nd Embodiment of this invention, the polarization rotation element 102, and each optical path. It is a figure which shows the example of 1 structure of the conventional wavelength selective switch. It is a figure which shows the other structural example of the conventional wavelength selective switch.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

[First Embodiment]
FIG. 1 is a diagram illustrating a configuration of an optical signal processing device including 2-in-1_1 × M_WSS according to the first embodiment of the present invention. The two WSSs are called WSS1 and WSS2.

  The optical circuit board 101 is an optical circuit board, and outputs light input from the optical fiber to the space and outputs light input from the space to the optical fiber. The input / output ports to and from the optical fiber are arranged so that a large number of groups each composed of one WSS1 port and one WSS2 port are arranged side by side. In the figure, the odd-numbered port k = 2m−1 (m: natural number) from the top is the WSS1 port, and the even-numbered port k = 2m is the WSS2 port. The total number of input / output ports is 2 (M + 1) because the number of input / output ports is 1, and the number of output ports is M.

  Here, the operation will be described using two sets of four ports indicated by 110 to 113 in the figure among the input / output ports. 110 and 112 are input / output ports of WSS1, and 111 and 113 are input / output ports of WSS2.

  The optical circuit board 101 includes 2 (M + 1) light beam input / output circuits including 120 to 123. In FIG. 1, among the input / output ports described above, the light beam input / output circuits corresponding to the set of input / output ports 110 and 111 are 120 and 121, and the light beam input / output circuit corresponding to the set of input / output ports 112 and 113 is shown. 122 and 123. The internal structure of the optical circuit board 101 will be described in detail later.

  Next, the operation of WSS1 will be described. The optical path of WSS1 is indicated by a broken line. As will be described later, the wavelength multiplexed light input to the optical circuit board 101 from the input / output port 110 propagates through two parallel optical paths indicated by 130 and 131 from the light beam input / output circuits 120 and 121, respectively. Is output as light. After passing through the polarization rotator 102, these pass through the cylindrical lens 103, the diffraction grating 104, the main lens 105, and the cylindrical lens 106, and irradiate the lower half area of the LCOS 107. At this time, the polarization of both lights propagating in the optical paths 130 and 131 is aligned with the TE polarization. This polarization operation will be described later.

  The light irradiated to the LCOS 107 is reflected at a predetermined angle so as to couple the light to a desired port among the output ports, here, the input / output port 112. The LCOS 107 operates only with respect to the TE polarized wave whose electric field vibrates in the y direction in the figure. Thereafter, the light propagated through the optical path 130 travels around the outside to the optical path 133, the light propagated through the optical path 131 travels through the inside to the optical path 132, and the light propagates in the reverse order of the forward path.

  The light propagating through the optical path 133 is recombined with the light beam input / output circuit 123, and the light transmitted through the optical path 132 is recombined with the light beam input / output circuit 122. These lights are integrated by the optical circuit board 101 and output from the input / output port 112. Since the LCOS 107 collects light at different positions in the direction perpendicular to the paper surface (x-axis direction) for each wavelength, the port selection operation in the LCOS 107 is performed for each wavelength, and thus operates as a wavelength selection switch.

  The cylindrical lenses 103 and 106 are cylindrical lenses having a curvature in the x direction in the drawing. The cylindrical lens 103 collimates the light emitted from the optical circuit board 101 and irradiates the diffraction grating 104, and the cylindrical lens 106 plays a role of condensing the dispersed light on the LCOS 107.

  Next, the operation of WSS2 will be described. The optical path of WSS2 is indicated by a solid line. Wavelength multiplexed light input from the input / output port 111 to the optical circuit board 101 is output from the light beam input / output circuits 120 and 121 to the optical paths 140 and 141, respectively, similarly to the WSS1, and the cylindrical lens 103, the diffraction grating 104, and the main lens. 105, propagates through the cylindrical lens 106 and reaches the LCOS 107. At this time, since the light ray angle when emitted from the optical circuit board 101 is different from that in the case of WSS1, the upper half area of the LCOS 107 is irradiated. The light irradiated to the LCOS 107 is reflected at a predetermined angle so as to couple the light to the input / output port 113. Thereafter, the optical path 140 is connected to the optical path 143 around the outside, the optical path 141 is connected to the optical path 142 around the inside, and the light propagates in the reverse order of the outward path. The light propagating through the optical path 143 is recombined with the light beam input / output circuit 123, and the light transmitted through the optical path 142 is recombined with the light beam input / output circuit 122. These lights are integrated by the optical circuit board 101 and output from the input / output port 113.

  As described above, WSS1 and WSS2 have different angles of beams emitted from the optical circuit board 101 and are spatially separated on the LCOS 107, and thus can be switched separately.

  Next, the relationship between the operation of the optical circuit board 101 and the polarization rotation element 102 and each optical path will be described in detail with reference to FIG.

  A polarization separation element 201 and a light beam incident / exit circuit 205 are formed on the optical circuit board 101, and each input / output port is first connected to the polarization separation element 201. The polarization separation element 201 has a function of separating the light input from the input / output waveguide 202 into two different polarized waves orthogonal to each other and outputting each from the input / output waveguides 203 and 204. Here, it is assumed that TE polarized light whose electric field vibrates in the y-axis direction is output from the input / output waveguide 203 and TM polarized light orthogonal to the TE polarized light is output from the input / output waveguide 204.

  Here, with respect to the k-th polarization separation element connected to the k-th port and its input / output waveguide, 201-204 are respectively 201 (k) -204 (k) (k: 1, 2,. .. 2 (M + 1))

  The light beam incident / exit circuit 205 emits light input from the input / output waveguides 206 and 207 toward the space at different angles. When input from the input / output waveguide 206, it is directed to the lower right direction (broken line) (optical paths 130 to 133) in the figure, and when input from the input / output waveguide 207, it is directed to the upper right direction (solid line) (optical paths 140 to 143). Emits light. Similarly, for the k-th light beam input / output circuit, 205 to 207 are changed from 205 (k) to 207 (k) (k: 1, 2,..., 2 (M + 1)). Let's represent.

  The polarization separation element 201 and the light beam incident / exit circuit 205 are connected as follows, as shown in FIG. That is, for m taking a natural number of M + 1 or less, four input / output waveguides 203 (2m-1), 204 (2m-1), 203 (2m), 204 (2m) straddling two polarization separation elements 201 are used. Are connected to four input / output waveguides 206 (2m-1), 206 (2m-1), 207 (2m-1), and 207 (2m) across the two light beam input / output circuits 205, respectively.

  That is, according to the functional description, in a set of the (2m-1) th input / output port belonging to WSS1 and the (2m) th input / output port belonging to WSS2, light is polarized. After that, the light beam input / output circuits which are different for each polarization are collected and connected so as to be output to the space at a predetermined angle different for each WSS. TE polarized light is output from the (2m-1) th light beam input / output circuit, and TM polarized light is output from the (2m) th light beam input / output circuit. In the figure, the thin line indicates TE polarized light and the thick line indicates TM polarized light. The solid line and the broken line indicate WSS2 and WSS1, respectively, as in FIG.

  The light beam emitted from the optical circuit board 101 passes through the polarization rotation element 102. The polarization rotator 102 is configured such that a glass part 208 that does not change the polarization state and a half-wave plate part 209 that rotates the polarization by 90 degrees repeatedly appear at the same period as the arrangement interval of the light beam input / output circuit 205. It is a rotating element. The glass portion 208 may not be glass and may be a hole as long as it can transmit light with low loss without changing the polarization state.

  With respect to the position in the y direction of the polarization rotation element 102, the light emitted from the light beam incident / exit circuit 205 (2m) is arranged to pass through the half-wave plate 209.

  The position in the z direction of the polarization rotation element 102 will be described. In FIG. 2, the change in polarization is drawn at a position with a gap after the optical circuit board 101 so that the change in polarization is easy to illustrate. However, the position of the polarization rotation element 102 is not limited to this and is given to the output polarization. It can be anywhere as long as the impact is the same. For example, the polarization rotation element 102 may be bonded to the optical circuit board 101 with an optical adhesive or the like without leaving a gap. Further, it may be embedded somewhere after the light beam input / output circuit 205 on the optical circuit board 101. That is, a method of mechanically forming a deep groove on the light beam incident / exit circuit 205 and inserting the polarization rotation element 102 therein may be employed.

  The TE-polarized light emitted from the (2m-1) -th light beam incident / exit circuit 205 (2m-1) passes through the glass portion 208 and is still TE-polarized light after passing through the polarization rotation element 102. Since the TM polarized light emitted from the 2m) light beam incident / exit circuit 205 (2m) passes through the half-wave plate 209, it becomes TE polarized light after passing through the polarization rotation element 102. That is, after passing through the polarization rotation element 102, the polarization state of all the light becomes TE polarized light. By equalizing the polarization state of all light to TE polarization in this way, beam deflection by LCOS is possible for all outgoing beams, and switching is performed.

  Also, the set of input / output ports 110 and 111 is the (2p-1) th and 2pth ports, and the set of input / output ports 112 and 113 is the (2q-1) th and 2qth ports. If the optical path of WSS1 is followed, it is as follows.

  The light input from the input / output port 110 is polarized and separated by the polarization separation element 201 (2p-1). First, regarding the TE polarized wave, it propagates from the input / output waveguide 203 (2p-1) to the input / output waveguide 206 (2p-1) and from the input / output end 120 of the light beam input / output circuit 205 (2p-1). The light is emitted to the optical path 130, passes through the glass portion 208 with TE polarization, and returns on the optical path 133 after switching. Next, it is converted to TM polarization by the half-wave plate 209 and re-coupled to the input / output end 123 of the light beam input / output circuit 205 (2q). Next, it propagates from the input / output waveguide 206 (2q) to the input / output waveguide 204 (2q-1) and is guided to the input / output waveguide 202 (2q-1) by the polarization separation element 201 (2q-1). Output from the input / output port 112.

  Next, regarding the TM polarized wave, it propagates from the input / output waveguide 204 (2p-1) to the input / output waveguide 206 (2p) to the optical path 131 from the input / output end 121 of the light beam input / output circuit 205 (2p). The light is emitted, converted into TE polarized light by the half-wave plate 209 and propagated, and returns to the optical path 132 after switching. Next, it passes through the glass portion 208 with TE polarization, and is recombined with the input / output end 122 of the light beam input / output circuit 205 (2q-1). Next, it propagates from the input / output waveguide 206 (2q-1) to the input / output waveguide 203 (2q-1) and is guided to the input / output waveguide 202 (2q-1) by the polarization separation element 201 (2q-1). And output from the input / output port 112.

  As described above, it can be seen that the light input from the input / output port 110 is output from the input / output port 112 regardless of the polarization. Since the operation of WSS2 is the same, detailed description is omitted, but the light input from the input / output port 111 is output from the input / output port 113 regardless of the polarization. That is, in the present invention, polarization diversity is established.

  One of the advantages of the present invention is that only one of TE and TM polarized light is input to one light beam input / output circuit 205. That is, in the design of the light beam entrance / exit circuit 205, it is not necessary to consider that both polarizations have the same characteristics (loss, beam diameter, propagation angle, etc.), and are different for TE polarization and TM polarization. It is good as a design.

  In the above description, the polarization is equalized to the TE polarization on the assumption that the LCOS 107 is arranged only to operate with respect to the TE polarized light. Of course, the LCOS 107 is arranged to operate only with respect to the TM polarized light. If so, it may be equalized to TM polarized light. In order to do this, in the polarization rotation element 102, the glass part 208 and the half-wave plate part 209 are replaced, or the polarization separation element 201 is changed to a z-axis symmetric structure, and the TM polarization is transmitted from the input / output waveguide 203. The TE polarized light may be output from the input / output waveguide 204.

  In the above description, the output destinations of WSS1 and WSS2 are the (2q-1) input / output port and the (2q) input / output port and are adjacent to each other. However, WSS1 and WSS2 can be switched independently. Therefore, it goes without saying that I / O ports can be set apart from each other, such as WSS1 is the (2q-1) I / O port and WSS2 is the (2q ') I / O port (q ≠ q').

  As a method of realizing the polarization separation element 201, for example, a Mach-Zehnder interferometer type polarization separation circuit as disclosed in Patent Document 4 can be used. Of course, not only this circuit configuration but another configuration may be used.

  Next, FIG. 3 shows an embodiment of the light beam incident / exit circuit 205 in the present invention. FIG. 3A shows a circuit in which the input / output waveguides 301 and 302 are connected to be inclined with respect to the slab waveguide 303, and the outgoing beam can be inclined according to the inclination of the input / output waveguide.

  FIG. 3B shows an example in which the input / output waveguides 301 and 302 are connected in parallel to the slab waveguide 303 and the lens function unit 304 is incorporated in the slab waveguide 303. As a method for realizing the lens function unit 304, a method of filling a lens-shaped deep groove with a substance having a refractive index different from that of the waveguide core, for example, resin or air, can be considered. The lens function unit 304 can convert the position difference between the input / output waveguides 301 and 302 into an angle difference and output the difference to the space.

  FIG. 3C shows a circuit called a Spatial Beam Transformer (SBT) comprising input / output waveguides 301 and 302, a first slab waveguide 305, a second slab waveguide 306, and an arrayed waveguide 307. For example, Non-Patent Document 1 shows an SBT circuit. The structure is close to an AWG (Arrayed Waveguide Grating) which is a wavelength multiplexer / demultiplexer, but the arrayed waveguide is of equal length and does not have a demultiplexing function. Since the slab waveguide has a lens function, the difference in position between the input / output waveguides 301 and 302 can be converted into an angular difference and output to the space.

  The light beam input / output circuit 205 can be realized by a method typified by those shown in FIGS. 3A to 3C. However, the structure is not limited to this, and a structure in which a plurality of methods are combined or completely different. The structure may be used.

  As described above, according to the present embodiment, simplification and simplification of the optical system can be realized in 2-in-1_WSS by integrating the polarization diversity optical system in the waveguide.

[Second Embodiment]
The second embodiment is 3-in-1_1 × M_WSS, which is a development of the first embodiment. Hereinafter, the second embodiment will be described, but the description of the same parts as the first embodiment will be omitted as appropriate.

  FIG. 4 is a diagram illustrating a configuration of an optical signal processing device including 3-in-1_1 × M_WSS according to the second embodiment of the present invention. Here, the three WSSs are referred to as WSS1, WSS2, and WSS3. The input / output ports are arranged such that a large number of groups in which the input / output ports of WSS1, the input / output ports of WSS2, and the input / output ports of WSS3 are arranged adjacent to each other are arranged. The k-th port in the figure is a WSS1 port if k = 3m−2 (m: natural number), a WSS2 port if k = 3m−1, and a WSS3 port if k = 3m. The total number of input / output ports is 3 (1 + M).

  In the figure, 410 is an input / output port of WSS1, 411 is an input / output port of WSS2, 412 is an input / output port of WSS3, 413 is an input / output port of WSS1, 414 is an input / output port of WSS2, 415 is an input / output of WSS3 It is assumed that it is a port.

  The optical circuit board 101 includes 2 (1 + M) light beam input / output circuits including 420 to 423 as in the first embodiment. Among the input / output ports described above, 420 and 421 are light beam input / output circuits corresponding to the set of input / output ports 410 to 412, and 422 and 423 are light beam input / output circuits corresponding to the set of input / output ports 413 to 415. is there.

  As in the first embodiment, light is emitted from the optical circuit board 101 as two parallel light beams from 420 and 421 when light is input from any of the input / output ports 410 to 412. The propagation angle is different for each. This angle difference becomes a position difference on the LCOS 107. In the present embodiment, the condensing position on the LCOS 107 is divided into three for each WSS and can be switched independently.

  In the case of WSS1, light is input from the input / output port 410, and its optical path passes through optical paths 430 and 431 indicated by broken lines to reach the LCOS 107, and in the return path, it passes through optical paths 433 and 432, respectively. Recombined with 422 and output from the input / output port 413.

  In the case of WSS2, light is input from the input / output port 411, and the optical path passes through optical paths 450 and 451 indicated by alternate long and short dash lines to reach the LCOS 107, and in the return path, passes through the optical paths 453 and 452, respectively. 422 and output from the input / output port 414.

  In the case of WSS3, light is input from the input / output port 412. The optical path passes through optical paths 440 and 441 indicated by solid lines and reaches the LCOS 107. In the return path, the optical path passes through optical paths 443 and 442, respectively. 422 is recombined and output from the input / output port 415.

  Next, the relationship among the optical circuit board 101, the polarization rotation element 102, and each optical path in the present embodiment will be described with reference to FIG.

  The point that the polarization separation element 201 is connected to each port is the same as in the first embodiment. Accordingly, the optical circuit board 101 includes a total of 3 (M + 1) polarization separation elements 201.

  The light beam input / output circuit 205 is different from the first embodiment in that the number of input / output ports is increased to three. The number of light beam input / output circuits 205 is 2 (M + 1), which is the same as in the first embodiment. The light beam entrance / exit circuit 205 emits light input from the input / output waveguides 501, 502, and 503 at different angles. When the signal is input from the input / output waveguide 501, the input / output waveguide is directed in the lower right direction (optical paths 430 to 433) in the drawing, and when input from the input / output waveguide 502 is input to the right direction (optical paths 450 to 453) in the drawing. When it is input from the waveguide 503, it is output in the upper right direction (optical paths 440 to 443) in the figure.

  The polarization separation element 201 and the light beam incident / exit circuit 205 are connected as follows. That is, for m taking a natural number of M + 1 or less, six input / output waveguides 203 (3m−2), 204 (3m−2), 203 (3m−1), 204 ( 3m-1), 203 (3m), 204 (3m) are six input / output waveguides 501 (2m-1), 501 (2m), 502 (2m- 1), 502 (2m), 503 (2m-1), and 503 (2m).

  Since the arrangement conditions and functions of the polarization rotation element 102 are the same as those in the first embodiment, the description thereof is omitted.

  The input / output ports 410, 411, 412 are the (3p-2) th, (3p-1) th, and 3pth input / output ports, and the input / output ports 413, 414, and 415 are (3q-2). ) Th, (3q-1) th, and 3qth input / output ports.

  Following the optical path of WSS1 is as follows. Light input from the input / output port 410 is polarized and separated by the polarization separation element 201 (3p-2). First, regarding the TE polarization, it propagates from the input / output waveguide 203 (3p-2) to the input / output waveguide 501 (2p-1) and from the input / output end 420 of the light beam input / output circuit 205 (2p-1). The light is emitted to the optical path 430, passes through the glass portion 208 with TE polarization, and returns on the optical path 433 after switching. Next, it is converted to TM polarized wave by the half-wave plate 209 and recombined with the input / output terminal 423 of the light beam input / output circuit 205 (2q). Next, it propagates from the input / output waveguide 501 (2q) to the input / output waveguide 204 (3q-2), and is guided to the input / output waveguide 202 (3q-2) by the polarization separation element 201 (3q-2). Output from the input / output port 413.

  Next, regarding the TM polarized wave, it propagates from the input / output waveguide 204 (3p-2) through the input / output waveguide 501 (2p) to the optical path 431 from the input / output end 421 of the light beam input / output circuit 205 (2p). The light is emitted, converted into TE polarized light by the half-wave plate 209 and propagated, and returns to the optical path 432 after switching. Next, it passes through the glass portion 208 with TE polarization, and is recombined with the input / output terminal 422 of the light beam input / output circuit 205 (2q-1). Next, it propagates from the input / output waveguide 501 (2q-1) to the input / output waveguide 203 (3q-2) and is guided to the input / output waveguide 202 (3q-2) by the polarization separation element 201 (3q-2). And output from the input / output port 413.

  As described above, it can be seen that the light input from the input / output port 410 is output from the input / output port 413 regardless of the polarization. Since the operations of WSS2 and WSS3 are the same, the detailed description is omitted, but the light input from the input / output port 411 is output from the input / output port 414 and input from the input / output port 412 regardless of the polarization. Light is output from the input / output port 415 regardless of the polarization. That is, also in this embodiment, polarization diversity is established as in the first embodiment.

  As described above, the present invention can be applied not only to 2-in-1 but also to 3-in-1 by developing a similar idea. Needless to say, if the extension from the first embodiment to the second embodiment is extended, not only 2-in-1 and 3-in-1 but also any N-in-1_WSS can be realized.

DESCRIPTION OF SYMBOLS 101 Optical circuit board 102 Polarization rotation element 103,106 Cylindrical lens 104 Diffraction grating 105 Main lens 107 LCOS
110-113, 410-415 I / O ports 121-123, 205, 420-423 Light beam input / output circuits 130-133, 140-143, 430-433, 440-443, 450-453 Optical path 201 Polarization separation element 202- 204, 206, 207, 301, 302, 501 to 503 I / O waveguides 303, 305, 306 Slab waveguide 304 Lens function unit 307 Array waveguide 1001, 1101 Input optical system 1002 Diffraction grating 1003 Main lens 1004 LCOS
1005, 1006 Input / output port group 1111 Input unit 1112 Output unit 1201 Polarization separation unit 1202 Polarization rotation unit 1203 SBT circuit 1102, 1103, 1105 Cylinder lens 1104 Diffraction grating 1106 LCOS

Claims (7)

An optical circuit board comprising a waveguide formed on the substrate;
Polarization control means for controlling the polarization state of light output from the optical circuit board;
Light modulating means for reflecting light so as to recombine light output from the optical circuit board to the optical circuit board;
An optical signal processing device comprising:
The optical circuit board is:
At least two polarization separation circuits that separate light input from one first input / output port into different first and second polarized waves orthogonal to each other and output from two second input / output ports;
Light of the same polarization output from the at least two polarization separation circuits is input from a plurality of third input / output ports, and the plurality of input lights correspond to each of the plurality of third input / output ports. At least two light beam input / output circuits that output at different angles;
Including
The polarization control means controls the polarization of light output from the light beam input / output circuit to a single polarization on which the light modulation means operates.
An optical signal processing device. The optical circuit board is:
M fourth input / output port groups, each of which has N input / output ports as one unit,
M polarization separation circuit groups in which the number of polarization separation circuits is N and one unit;
The number of the third input / output ports is M, and the number of the light beam input / output circuits is N, and the number of the light beam input / output circuits is M.
Each of the fourth input / output port groups is connected to the first input / output port of each of the polarization separation circuit groups,
The N second input / output port groups that output the first polarization of each of the polarization separation circuit groups are the first light beam input / output circuits of the light beam input / output circuits. Connected to each of the N third input / output ports.
The N second input / output port groups that output the second polarized wave of each of the polarization separation circuit groups are the second light beam input / output circuits of the light beam input / output circuits. Connected to each of the N third input / output ports,
The optical signal processing device according to claim 1.   The polarization control means has a first region that does not change the polarization state and a second region that rotates the polarization by 90 °, and the first region and the second region are the light beam entrance and exit. The optical signal processing apparatus according to claim 1, wherein the optical signal processing apparatus is alternately and repeatedly arranged at the same array interval as the circuit.   4. The optical signal processing apparatus according to claim 1, wherein the polarization control unit is bonded to a light emitting end face of the optical circuit board on the light beam incident / exit circuit side. The light beam input / output circuit is
A plurality of input / output waveguides respectively connected to the third input / output port;
A first slab waveguide in which the plurality of input / output waveguides are connected to one end at different angles;
An arrayed waveguide having one end connected to the other end of the first slab waveguide;
A second slab waveguide connected to the other end of the arrayed waveguide;
The optical signal processing apparatus according to claim 1, further comprising: The light beam input / output circuit is
A plurality of input / output waveguides respectively connected to the third input / output port;
A slab waveguide in which the plurality of input / output waveguides are connected to one end at different angles;
The optical signal processing apparatus according to claim 1, further comprising: The light beam input / output circuit is
A plurality of input / output waveguides respectively connected to the third input / output port;
A slab waveguide in which the plurality of input / output waveguides are parallel and connected to one end, and includes a region having at least two refractive indexes on an optical path of light propagating through the slab waveguide;
The optical signal processing apparatus according to claim 1, further comprising:

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