JP5471446B2 - Wavelength selective switch, wavelength selective device, and optical module - Google Patents

Description

The present invention provides an optical network node using the wavelength separation multiplexing techniques, the wavelength selection device to change the add-drop function or an optical path for performing multiplexing-demultiplexing of the signal light of a specific wavelength, an optical module,及Beauty wave The long selection switch.

  Along with the rapid increase in traffic in the optical communication market in recent years, in addition to the improvement in communication speed, a technique for increasing the network utilization efficiency and a wavelength division multiplexing (WDM) technique have been developed. In particular, ROADM (Reconfigurable Optical Add / Drop Multiplexer) that combines wavelength multiplexing technology and switching technology and advanced optical cross-connect technology are actively studied. In particular, a wavelength selection device that can multiplex multiplexed light waves and then multiplex them again in any combination and set a route to any output port is a key component that plays a central role in optical cross-connects It is.

  In the configuration related to the present invention, an optical function combining a wavelength multiplexing / demultiplexing element using AWG (Arrayed Waveguide Grating) or a grating and an optical switch using a planar optical circuit or MEMS (Micro Electro Mechanical System) technology. An element is used. For example, a 16-channel AWG add / drop multiplexer has been proposed as a node element having a ROADM function.

  For AWG add / drop multiplexers, see K.K. Okamoto, M .; Okuno, A .; Himeno and Y.M. Ohmori, “16-channel optical add / drop multiplexer constraining of arrayed-waveguides grafting and double-gate switches”, Electronics letters 1 st. 32 No. 16, pp. 1471-1472. This AWG add / drop multiplexer is constructed by monolithically integrating two types of components, that is, four sets of AWGs and a Mach-Zehnder 2 × 2TO switch on the same optical waveguide substrate.

  As shown in this example, in order to integrate four AWGs as add / drop multiplexers and function as add / drop multiplexers, the center wavelengths of the AWGs must match, Need to be managed precisely. On the other hand, US Pat. No. 5,414,548 proposes a configuration that reduces the total number of AWGs by consolidating the multiplexing and demultiplexing functions into one AWG.

  The proposals related to the present invention described above show one typical form of ROADM. However, this ROADM does not have a function of switching the optical path, and there is a disadvantage that the configuration becomes complicated when the function is added separately. As another configuration, an ROADM element having a similar function by using a MEMS switch has been proposed. However, since this ROADM element has a movable part inside, problems remain in terms of manufacturing cost and reliability. Each proposal shows a typical form of ROADM, which does not have a function of switching to an optical path of a light wave of a specific wavelength, and the configuration becomes complicated when the function is added separately. There is a problem.

  As described above, when a multi-input / multi-output wavelength selection device is configured by combining an AWG and an optical switch, a plurality of AWGs are required. Therefore, the plurality of AWGs and the optical switch are combined. As a result, there is a problem that the configuration of the wavelength selection device becomes complicated.

  On the other hand, when a grating or a MEMS mirror is used, there is a possibility that a wavelength selective switch having a relatively large scale can be realized. However, in the case of this configuration, there is a problem from the viewpoint of operation reliability and manufacturing cost because it has a movable part and requires a mounting process using micro-optics. Therefore, if the manufacture of the wavelength selective switch by the PLC (planar optical circuit) technology is realized, it becomes possible to realize an optical element superior to other systems in terms of operation reliability and manufacturing cost.

An object of the present invention is to solve the above-described problems using a PLC technology that can be manufactured at low cost from such a viewpoint, and has a wavelength selection device that has an add / drop function and can perform multiple input-multiple output, It is to provide an optical module, an及beauty wavelength selection switch.

Furthermore, wavelength selection switch of the present invention, a plurality of linear optical waveguides, a plurality of closed loop shaped optical waveguide for being arranged to cross the linear optical waveguides for switching the optical path of the signal light of a specific wavelength, linear A plurality of ring-shaped optical waveguides optically coupled to the linear optical waveguide and the closed-loop optical waveguide at each intersection of the optical waveguide and the closed-loop optical waveguide, and a ring provided on each ring-shaped optical waveguide A plurality of changing means for changing the effective refractive index of the optical waveguide. And the ring-shaped optical waveguide is arrange | positioned inside the closed loop which a closed-loop optical waveguide comprises.

The first wavelength selection device according to the present invention includes a first linear optical waveguide and a plurality of optical waveguides for multiplexing and demultiplexing signal light of a specific wavelength arranged so as to intersect the first linear optical waveguide. And a plurality of optically coupled first and second linear optical waveguides at respective intersections of the second linear optical waveguide and the first linear optical waveguide and the second linear optical waveguide. And a plurality of first changing means for changing the effective refractive index of the first ring-shaped optical waveguide provided in each first ring-shaped optical waveguide. When,
A plurality of third linear optical waveguides including a linear optical waveguide optically connected to the end of the first linear optical waveguide, and arranged in a grid pattern crossing the third linear optical waveguide. A plurality of fourth linear optical waveguides for switching the optical path of signal light of a specific wavelength, and third and fourth straight lines at respective intersections of the third linear optical waveguide and the fourth linear optical waveguide A plurality of second ring-shaped optical waveguides that are optically coupled to the respective optical waveguides, and the effective refractive index of the second ring-shaped optical waveguides provided in each of the second ring-shaped optical waveguides. Therefore, a wavelength selective switch having a plurality of second changing means is provided.

Further, the second wavelength selection device of the present invention combines a plurality of first linear optical waveguides and signal light of a specific wavelength arranged in a lattice pattern intersecting the first linear optical waveguides. A plurality of second linear optical waveguides for waving, and first and second linear optical waveguides at respective intersections of the first linear optical waveguide and the second linear optical waveguide, respectively. A plurality of first ring-shaped optical waveguides coupled to each other, and a plurality of first ring-shaped optical waveguides provided in each of the first ring-shaped optical waveguides for changing the effective refractive index of the first ring-shaped optical waveguide. A wavelength filter having changing means;
A plurality of third linear optical waveguides that are optically connected to the ends of the plurality of first linear optical waveguides, and a signal light having a specific wavelength disposed across the third linear optical waveguide. A plurality of closed-loop optical waveguides for switching optical paths, and optically coupled to the linear optical waveguide and the closed-loop optical waveguide, respectively, at the intersections of the third linear optical waveguide and the closed-loop optical waveguide. A plurality of second ring-shaped optical waveguides, and a plurality of second change means for changing the effective refractive index of the second ring-shaped optical waveguides provided in each second ring-shaped optical waveguide. The second ring-shaped optical waveguide includes a wavelength selective switch disposed inside the closed loop formed by the closed-loop optical waveguide.

  The optical module of the present invention includes the above-described wavelength selection device of the present invention, a control circuit that controls each changing means of the ring-shaped optical waveguide, and a temperature adjustment circuit that adjusts the temperature of the wavelength selection device.

  According to the present invention, a ring-shaped optical waveguide can perform a series of functions such as demultiplexing, optical path switching, and multiplexing on signal light of a specific wavelength in wavelength multiplexed signal light. In addition, according to the wavelength selection device of the present invention, at the same time as adding / dropping the signal light of the specific wavelength in the input wavelength multiplexed signal light, the signal light of the specific wavelength is output to an arbitrary output port Thus, the ROADM function and the optical path switching function from not only a plurality of output ports but also a plurality of input ports can be realized.

It is a schematic diagram which shows the structure of the wavelength selection apparatus of 1st Embodiment. It is a schematic diagram for demonstrating operation | movement of a ring-shaped optical waveguide filter. It is a figure which shows the wavelength transmission characteristic of a ring-shaped optical waveguide filter. It is a schematic diagram which shows the 1st example explaining switching of the optical path in a wavelength selection apparatus. It is a schematic diagram which shows in detail the 1st example explaining switching of the optical path in a wavelength selection apparatus. It is a schematic diagram which shows the 2nd example explaining switching of the optical path in a wavelength selection apparatus. It is a schematic diagram which shows in detail the 2nd example explaining switching of the optical path in a wavelength selection apparatus. It is a schematic diagram which shows the wavelength selection apparatus of 2nd Embodiment. It is a schematic diagram which shows the wavelength selection apparatus of 3rd Embodiment. It is a schematic diagram which shows the optical module of embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram showing a configuration of a 3-input-3 output wavelength selection device of the present embodiment. As shown in FIG. 1, the wavelength selection device of this embodiment includes an add / drop filter 114 that multiplexes and demultiplexes signal light of a specific wavelength, and is optically connected to the add / drop filter 114 and has a specific wavelength. And a wavelength selective switch 115 for switching the optical path of the signal light.

  The wavelength selective switch 115 includes a linear optical waveguide 103 that forms a waveguide array, a closed-loop optical waveguide 104 that is arranged so as to intersect the linear optical waveguide 103 and forms a waveguide array, and the linear optical waveguide 103. And a ring-shaped optical waveguide 105 disposed in an adjacent waveguide array so as to be optically coupled to both of the closed-loop optical waveguide 104 and on a SOI (Silicon on Insulator) substrate 101. It is formed as a channel type optical waveguide. A heater 106 for changing the effective refractive index of the ring-shaped optical waveguide 105 is disposed above the ring-shaped optical waveguide 105, and is configured as a switch for switching the optical path of signal light having a specific wavelength. . One end of the linear optical waveguide 103 of the wavelength selective switch 115 is optically connected to the output port array 102, and the other end is optically connected to the output end of the add / drop filter 114. .

  The add / drop filter 114 is formed as a waveguide array and is formed by a linear optical waveguide 109 and a linear optical waveguide 110 which are orthogonal to each other, and straight lines intersecting each other with a linear optical waveguide formed in a matrix (lattice shape). The ring-shaped optical waveguides 108 and 110 are arranged in close proximity so as to be optically coupled to both of the optical waveguides 109 and 110 to form a waveguide array. The linear optical waveguide 110 of the add / drop filter 114 is optically connected to the input port array 111. A heater 112 for changing the effective refractive index of the ring-shaped optical waveguide 108 is disposed on the ring-shaped optical waveguide 108.

  Each optical waveguide of the add / drop filter 114 and the wavelength selective switch 115 is formed on a semiconductor substrate. Each optical waveguide is configured by sandwiching a core layer made of a semiconductor having a refractive index higher than that of the clad layer between clad layers made of a semiconductor. The heaters 106 and 112 are disposed in the ring-shaped optical waveguides 105 and 108, and have anode and cathode electrodes (not shown) for applying a voltage to the core layer of the ring-shaped optical waveguides 105 and 108. Yes.

  Each optical waveguide may be configured by sandwiching a core layer made of a dielectric having a higher refractive index than that of the clad layer between clad layers made of a dielectric. In the case of this configuration, the heater is disposed in the ring-shaped optical waveguide, and has respective electrodes that form an anode and a cathode for applying a voltage to the core layer of the ring-shaped optical waveguide. In this configuration, a voltage is applied to the core layer of the ring-shaped optical waveguide, and the refractive index of the core layer is changed by the electro-optic effect.

  Each of the optical waveguides described above is configured as a channel-type optical waveguide, but may be configured as a rib-type (ridge-type) optical waveguide.

  Hereinafter, the operation of the wavelength selection device of this embodiment will be described. FIG. 2A is a wavelength filter composed of two linear optical waveguides and a ring-shaped optical waveguide optically connected to these linear optical waveguides, and is a basic element of the wavelength selection device of this embodiment. A schematic diagram of an add / drop filter (ring-shaped optical waveguide filter) 114 is shown.

  As shown in FIG. 2A, among the wavelength multiplexed signal light input to one linear optical waveguide 201, only the specific wavelength light (resonance wavelength light λ2) propagates through the other linear optical waveguide 202 and is separated. Waves (Drop) and other wavelength light propagate through the straight optical waveguide 201 as they are (Thru (= through)). FIG. 2B shows the wavelength transmission characteristics of the add / drop filter. The drop waveguide 203 transmits only the specific wavelength component λ2, and the transmittance of other wavelengths is sufficiently low. The wavelength to be transmitted can be adjusted (tuned) by a heater on the ring-shaped optical waveguide 208.

  As shown in FIG. 1, wavelength multiplexed signal light input from one port of the input port array 111 is demultiplexed (dropped) to extract signal light of a specific wavelength from the drop port 113 by an add / drop filter 114. A signal light having a specific wavelength is inserted from the add port 107 and added (add) at the same time, and then input to the wavelength selective switch 115. Then, the wavelength selection switch 115 switches the optical path for each wavelength and outputs it to the output port array 102.

  3A, 3B, 3C, and 3D show an example of the optical path switching state in the case of four-wave multiplexing by the wavelength selective switch 115. FIG. In FIGS. 3A, 3B, 3C, and 3D, the numerical value shown below each ring-shaped optical waveguide 105 represents the channel number of the resonant wavelength light. In addition, it has shown that the filter of the ring-shaped optical waveguide in which the numerical value is not described exists in the state which does not resonate to any channel wavelength.

  3A and 3B output all the wavelength multiplexed signal light input to the port A1 to the port B3, output all the wavelength multiplexed light input to the port A3 to the port B1, and also input the wavelength input to the port A2. A combination of resonance wavelengths of the ring-shaped optical waveguides when all the multiplexed light is output to the port B2 is shown.

  3C and 3D output one channel wavelength λ2 of the wavelength multiplexed light input to the port A1 to the port B1, output the other wavelengths to the port B3, and all of the wavelength multiplexed light input to the port A2. Output to port B2, output one wavelength λ2 of the wavelength multiplexed light input to port A3 to port B3, and output the other wavelengths to port B1. Shows the combination.

  In the configuration of the present embodiment, the optical path of the input / output port can be switched in any combination of channel wavelengths depending on the combination of resonance wavelengths.

  As described above, the wavelength selection device according to the present embodiment performs control so that any wavelength signal light in the input wavelength multiplexed signal light is output to any output port. Inside the wavelength selection device, a series of functions such as demultiplexing (separation) of wavelength multiplexed signal light, switching of optical paths, and multiplexing are performed simultaneously by ring-shaped optical waveguides arranged in a lattice shape. A wavelength filter having two intersecting linear optical waveguides and a ring-shaped optical waveguide adjacent to each of these linear optical waveguides guides only a specific wavelength light to resonate to one linear optical waveguide. Thus, it serves to guide light waves of other non-resonant wavelength components to the other linear optical waveguide. Furthermore, since the resonance wavelength can be changed by changing the effective refractive index of the ring-shaped optical waveguide, the wavelength selection device can change the optical path of a light wave having a specific wavelength. The number of rows of wavelength filters arranged in a grid is set equal to the number of output ports of the wavelength selector, and the number of columns is set equal to the number of multiplexed wavelength channels. Multiplexed light demultiplexing, optical path switching, and multiplexing functions are performed simultaneously. For this reason, the wavelength selection apparatus of this embodiment has an advantage that it is not necessary to integrate separate functions such as AWG and optical switch unlike the wavelength selection apparatus related to the present invention. Further, in the wavelength selection device of the present embodiment, the add / drop function of the signal light of the specific wavelength can be similarly performed using the function of the ring-shaped optical waveguide. In the wavelength selection device of the present embodiment, the addition / drop of the lightwave signal and the assignment of the output port for each wavelength signal light are determined by the combination of the resonance wavelengths in the ring-shaped optical waveguides arranged in a lattice shape. For this reason, the wavelength selection apparatus of this embodiment can perform a required operation only by controlling each ring-shaped optical waveguide.

  That is, the wavelength selection apparatus of the present embodiment performs add / drop on the signal light of the specific wavelength in the input wavelength multiplexed signal light, and simultaneously outputs the signal light of the specific wavelength to an arbitrary output port. It has a function to control. Therefore, the wavelength selection device not only outputs arbitrary signal light to a plurality of output ports, but also realizes a ROADM function and an optical path switching function for arbitrary signal light input from a plurality of input ports. it can.

  The first effect of the wavelength selection device of the present embodiment is that a multi-input / multi-output optical path switching function and a ROADM function can be realized simultaneously. That is, the above-described function can be easily realized by a combination of resonance wavelengths in the ring-shaped optical waveguides arranged in a lattice shape. A large number of AWGs and optical switches that are necessary when these functions are realized by a method related to the present invention are not required in this embodiment, and a large-scale apparatus configuration is not required.

  The second effect of the wavelength selection device of this embodiment is to reduce the size and the manufacturing cost. That is, this embodiment can be manufactured by a planar optical circuit technology (PLC technology) because the constituent elements of the optical circuit are only ring optical waveguides. For this reason, according to this embodiment, compared with the structure relevant to this invention which combined several components from which a characteristic and a function differ, size reduction and cost reduction can be implement | achieved easily.

  A third effect of the wavelength selection device of the present embodiment is that the operation reliability can be improved. That is, in this embodiment, since the constituent elements of the optical circuit are only ring-shaped optical waveguides, the operation reliability is improved as compared with the configuration related to the present invention in which a plurality of parts having different sensitivities to changes in the external environment are combined. Can be easily realized.

  A fourth effect of the wavelength selection device according to the present embodiment is that power consumption can be reduced. The power consumption necessary for operating the wavelength selection device of the present embodiment is mainly the power consumption accompanying the operation of the ring-shaped optical waveguide. When a function similar to that of the present invention is realized in a configuration related to the present invention, an enormous number of composite parts are required, and a large amount of electric power is required to control and drive these parts. That is, the wavelength selection apparatus according to the present embodiment can achieve a reduction in power consumption as compared with the configuration related to the present invention.

(Second Embodiment)
As a second embodiment, the details of a wavelength selection apparatus having a configuration suitable for switching between multiple input and multiple output optical paths will be described. FIG. 4 is a schematic diagram showing the configuration of a wavelength selection device that is M input-M output and supports N-channel wavelength multiplexing. As shown in FIG. 4, the wavelength selection apparatus of this embodiment includes an add / drop filter 314 that combines and demultiplexes signal light of a specific wavelength, and is optically connected to the add / drop filter 314 and has a specific wavelength. And a wavelength selective switch 315 for switching the optical path of the signal light.

  The wavelength selective switch 315 is a linear optical waveguide 303 forming an M number of waveguide arrays formed on the SOI substrate 301, and is disposed so as to intersect the linear optical waveguide 303 to form a waveguide array (N + 1). A closed loop-shaped optical waveguide 304, a ring-shaped optical waveguide 305 disposed in close proximity so as to be optically coupled to both the linear optical waveguide 303 and the closed-loop optical waveguide 304, and a linear optical waveguide 303 This is a wavelength selective switch having, as a basic element, a ring-shaped optical waveguide 306 arranged close to the outside of the closed loop of the loop-shaped optical waveguide 304 and forming a waveguide array. On top of the ring-shaped optical waveguides 305 and 306, a heater 307 for changing their effective refractive index is disposed. One end of the linear optical waveguide 303 of the wavelength selective switch 315 is optically connected to the output port array 302, and the other end of the linear optical waveguide 303 is optically connected to the output end of the add / drop filter 314. It is connected to the.

  The add / drop filter 314 includes a linear optical waveguide 308 and a linear optical waveguide 311 that are orthogonal to each other in a waveguide array, and an optical waveguide formed in a lattice shape by the linear optical waveguide 311 and the intersecting linear waveguides 308 and 311. And a ring-shaped optical waveguide 309 arranged in close proximity so as to be optically coupled to form a waveguide array. The linear optical waveguide 311 of the add / drop filter 314 is optically connected to the input port array 312. In addition, a heater 310 for changing the effective refractive index of the ring-shaped optical waveguide 309 is disposed above each ring-shaped optical waveguide 309.

  The basic operation in this embodiment is the same as that in the first embodiment described above. However, in the present embodiment, the ring-shaped optical waveguide is arranged not only inside the closed loop of the closed-loop optical waveguide but also outside the closed loop in the optical path switching operation portion. Thereby, the freedom degree which switches an optical path is improved. With this configuration, the present embodiment enables switching of optical paths in a multi-input / multi-output wavelength selection type. In addition, the present embodiment has a function that operates in the same manner as the first embodiment with respect to the add / drop (multiplexing and demultiplexing) function of the lightwave signal.

(Third embodiment)
Next, as a third embodiment, an example of a 1-input / multi-output wavelength selection apparatus having a simple configuration will be described. FIG. 5 shows a schematic diagram of a 1 × M type wavelength selection device.

  As shown in FIG. 5, the wavelength selection device of this embodiment includes an add / drop filter 423 that multiplexes and demultiplexes signal light of a specific wavelength, and a specific wavelength that is optically connected to the add / drop filter 423. And a wavelength selective switch 419 for switching the optical path of the signal light.

  The wavelength selective switch 419 includes a linear optical waveguide 415 forming a waveguide array formed on the SOI substrate 410, a linear optical waveguide array 417 formed so as to intersect the linear optical waveguide 415, and each of these straight lines. The ring-shaped optical waveguides 415 and 417 are arranged in close proximity so as to be optically coupled to both the optical waveguides 415 and 417, and are formed in an array shape, and are formed as channel-type optical waveguides. A heater 420 for changing the effective refractive index of the ring-shaped optical waveguide 416 is disposed above each ring-shaped optical waveguide 416, and this heater 420 is configured as a switch for switching the optical path of wavelength signal light. ing. One end of the linear optical waveguide 415 of the wavelength selective switch 419 is optically connected to the output port array 418, and the other end of the linear optical waveguide 415 is the linear optical waveguide 415 forming the waveguide array. Only the linear waveguides in the first row are optically connected to the output end of the add / drop filter 423.

  The add / drop filter 423 includes a waveguide formed in a lattice shape by a linear optical waveguide 413 and a linear waveguide 411 that are orthogonal to each other in a waveguide array, and the linear waveguide 413 and the linear waveguide 411. And a ring-shaped optical waveguide 424 which is disposed in close proximity so as to be optically coupled to both of them to form a waveguide array. The linear optical waveguide 413 of the add / drop filter 423 is optically connected to the input port 412. Further, a heater 425 for changing the effective refractive index of the ring-shaped optical waveguide 424 is disposed on the ring-shaped optical waveguide 424.

  The operation in this embodiment will be described below. Wavelength multiplexed signal light input to the input port 412 is extracted by adding / dropping an arbitrary wavelength channel by an add / drop filter 423 or being combined and added by an arbitrary wavelength channel. In the wavelength selection switch 419, wavelength multiplexed light separation, optical path switching, and multiplexing operations are performed and output to the output port 418. Since the wavelength selective switch 419 has a one-input / multiple-output structure, the closed-loop waveguide as in the first and second embodiments is not necessarily required, and can be configured relatively easily.

  Moreover, you may comprise as an optical module provided with the wavelength selection apparatus of this embodiment mentioned above. As shown in FIG. 6, this optical module includes the above-described wavelength selection device 501 of the present embodiment, a control circuit 502 that controls the heater of the ring-shaped optical waveguide of the wavelength selection device 501, and the temperature of the wavelength selection device 501. And a temperature adjustment circuit 503 for adjustment. The temperature adjustment circuit 503 has, for example, a thermistor for detecting a temperature change of the wavelength selection device 501, and the control circuit 502 drives and controls the heater of the ring-shaped optical waveguide based on the operation of the thermistor. Configured to perform temperature regulation.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above-described embodiments. Various changes that can be understood by those skilled in the art can be made within the scope of the present invention with respect to the configuration and details of the present invention.

  This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2007-287283 for which it applied on November 5, 2007, and takes in those the indications of all here.

Claims (16)

A plurality of linear optical waveguides, a plurality of closed-loop optical waveguides arranged to intersect the linear optical waveguides for switching the optical path of signal light of a specific wavelength, the linear optical waveguides and the closed-loop optical waveguides A plurality of ring-shaped optical waveguides that are optically coupled to the linear optical waveguide and the closed-loop optical waveguide, respectively, at each intersection of the ring-shaped optical waveguide, and the ring-shaped optical waveguide provided in each ring-shaped optical waveguide. A plurality of changing means for changing the effective refractive index,
The wavelength selective switch, wherein the ring-shaped optical waveguide is disposed inside a closed loop formed by the closed-loop optical waveguide. The wavelength selective switch according to claim 1 , wherein the ring-shaped optical waveguide is disposed inside and outside a closed loop formed by the closed-loop optical waveguide. Each of the optical waveguides is formed on an SOI substrate,
2. The wavelength selective switch according to claim 1 , wherein the changing means is a heater disposed in the vicinity of the ring-shaped optical waveguide. Each of the optical waveguides is formed on a semiconductor substrate,
Each optical waveguide is configured by sandwiching a core layer made of a semiconductor having a refractive index higher than that of the clad layer between clad layers made of a semiconductor,
2. The wavelength selection according to claim 1 , wherein the changing means includes an anode electrode and a cathode electrode that are arranged in the ring-shaped optical waveguide and apply a voltage to the core layer of the ring-shaped optical waveguide. switch. Each of the optical waveguides is configured by sandwiching a core layer made of a dielectric having a higher refractive index than the clad layer between clad layers made of a dielectric,
2. The wavelength selection according to claim 1 , wherein the changing means includes an anode electrode and a cathode electrode that are arranged in the ring-shaped optical waveguide and apply a voltage to the core layer of the ring-shaped optical waveguide. switch. The wavelength selective switch according to claim 1 , wherein each optical waveguide is a channel-type optical waveguide. The wavelength selective switch according to claim 1 , wherein each optical waveguide is a rib-type optical waveguide. A first linear optical waveguide, a plurality of second linear optical waveguides arranged so as to intersect the first linear optical waveguide, and for combining and demultiplexing signal light of a specific wavelength; A plurality of first ring-shaped optical waveguides optically coupled to the first and second linear optical waveguides at respective intersections of one linear optical waveguide and the second linear optical waveguide; A plurality of first changing means provided in each of the first ring-shaped optical waveguides for changing an effective refractive index of the first ring-shaped optical waveguide;
A plurality of third linear optical waveguides including a linear optical waveguide optically connected to an end of the first linear optical waveguide, and in a lattice shape intersecting the third linear optical waveguide A plurality of fourth linear optical waveguides arranged to switch the optical path of the signal light having a specific wavelength, and the third linear optical waveguides at the intersections of the third linear optical waveguides and the third linear optical waveguides. And a plurality of second ring-shaped optical waveguides optically coupled to the fourth linear optical waveguide, and the second ring-shaped optical waveguide provided in each of the second ring-shaped optical waveguides A plurality of second changing means for changing the effective refractive index of the wavelength selective switch,
A wavelength selection device comprising: A plurality of first linear optical waveguides and a plurality of second linear optical waveguides arranged in a lattice pattern so as to intersect the first linear optical waveguides for multiplexing and demultiplexing signal light of a specific wavelength A plurality of waveguides and optically coupled to the first and second linear optical waveguides at respective intersections of the first linear optical waveguide and the second linear optical waveguide. A wavelength having a first ring-shaped optical waveguide and a plurality of first changing means provided in each of the first ring-shaped optical waveguides for changing an effective refractive index of the first ring-shaped optical waveguide. Filters,
A plurality of third linear optical waveguides that are optically connected to ends of the plurality of first linear optical waveguides, and a signal of a specific wavelength that is arranged to intersect the third linear optical waveguide. A plurality of closed-loop optical waveguides for switching the optical path of the light, and the linear optical waveguide and the closed-loop optical waveguide are respectively optically crossed at the intersections of the third linear optical waveguide and the closed-loop optical waveguide. A plurality of second ring-shaped optical waveguides coupled to each other, and a plurality of second ring-shaped optical waveguides provided in each of the second ring-shaped optical waveguides for changing the effective refractive index of the second ring-shaped optical waveguide. And the second ring-shaped optical waveguide has a wavelength selective switch disposed inside a closed loop formed by the closed-loop optical waveguide;
A wavelength selection device comprising: The wavelength selection apparatus according to claim 9 , wherein the second ring-shaped optical waveguide of the wavelength selective switch is disposed inside and outside a closed loop formed by the closed-loop optical waveguide. Each of the optical waveguides is formed on an SOI substrate,
9. The wavelength selection device according to claim 8 , wherein each of the changing units is a heater disposed in the vicinity of the ring-shaped optical waveguide. Each of the optical waveguides is formed on a semiconductor substrate,
Each optical waveguide is configured by sandwiching a core layer made of a semiconductor having a refractive index higher than that of the clad layer between clad layers made of a semiconductor,
9. The wavelength according to claim 8 , wherein each of the changing means includes an anode electrode and a cathode electrode that are arranged in the ring-shaped optical waveguide and apply a voltage to the core layer of the ring-shaped optical waveguide. Selection device. Each of the optical waveguides is configured by sandwiching a core layer made of a dielectric having a higher refractive index than the clad layer between clad layers made of a dielectric,
9. The wavelength according to claim 8 , wherein each of the changing means includes an anode electrode and a cathode electrode that are arranged in the ring-shaped optical waveguide and apply a voltage to the core layer of the ring-shaped optical waveguide. Selection device. The wavelength selection device according to claim 8 , wherein each of the optical waveguides is a channel-type optical waveguide. The wavelength selection device according to claim 8 , wherein each optical waveguide is a rib-type optical waveguide. A wavelength selection device according to claim 8 ,
A control circuit for controlling each of the changing means of the ring-shaped optical waveguide;
A temperature adjustment circuit for adjusting the temperature of the wavelength selection device;
An optical module comprising:

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