JP2015011225A - Control method for optical signal selection device and optical signal selection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the control method of an optical signal selection device for suppressing the occurrence of crosstalk in the case of switching an input/output optical fiber array for outputting an optical signal and an optical signal selection device.SOLUTION: An optical signal selection device includes: an input/output optical fiber array in which a plurality of optical fibers are arrayed along a predetermined direction; a wavelength spectroscope for dispersing the input signal in a spectral direction; an optical deflector for reflecting the optical signal at a predetermined angle, and for coupling it with a desired fiber; and a control device having a control part for controlling the angle, in which the input signal is output from a desired fiber. In the control method of the optical signal selection device including an output port switching step, the step includes: a first switching step of switching the reflection direction of the optical signal in the optical deflector from a first output port direction to a relay position direction separated from a straight line on which the fiber array is arrayed; and a second switching step of switching the reflection direction of the optical signal from the relay position or the other relay position direction to a second output port direction, and each step consists of a plurality of gradual processes.

Description

  The present invention relates to an optical signal selection device control method and an optical signal selection device.

  In an optical network to which wavelength division multiplexing (WDM) is applied, in order to form a more flexible network, the optical signal path is switched without changing the optical signal to an electrical signal. The importance of signal selection devices is increasing. As the above optical signal selection device, for example, a device using a reflection type phase modulator has been proposed. As the reflection type phase modulator, there is a phase modulation element array (for example, LCOS: Liquid Crystal on Silicon) in which reflection type liquid crystal elements which are phase modulation elements are arranged in a two-dimensional form. It is considered as an effective method (see Patent Document 1).

Special table 2007-510957 gazette

  In such an optical signal selection device that outputs an input optical signal from a desired input / output optical fiber array, when the output input / output optical fiber array is switched, a part of the optical signal is input / output light before and after the switching. There are cases where crosstalk occurs due to input to an input / output optical fiber array other than the fiber array.

  The present invention has been made in view of the above, and provides an optical signal selection device control method and an optical signal selection device that suppress the occurrence of crosstalk when switching input / output optical fiber arrays that output optical signals. The purpose is to do.

  In order to solve the above-described problems and achieve the object, a control method for an optical signal selection device according to the present invention includes an input / output optical fiber array in which a plurality of optical fibers are arranged along a predetermined switch direction, and the input / output optical fiber array. A wavelength spectrometer that splits the optical signal input from the output optical fiber array in a direction substantially perpendicular to the switch direction, and reflects the split optical signal at a predetermined angle to form a desired input / output optical fiber array. An optical deflector to be coupled, and a control device having a control unit that controls an angle of reflecting the optical signal of the optical deflector, and outputs the input optical signal from a desired input / output optical fiber array An optical signal selection device comprising: an output port switching step of switching the output input / output optical fiber array from a first output port to a second output port; The output port switching step switches the reflection direction of the optical signal at the optical deflector from the direction with respect to the first output port to the direction with respect to the relay position separated from the straight line on which the input / output optical fiber array is arranged. Including a first switching step and a second switching step for switching from the direction with respect to the relay position or another relay position to the direction with respect to the second output port, wherein the first switching step and the second switching step are respectively It consists of a plurality of stepwise processes.

  In the control method of the optical signal selection device according to the present invention, in the above invention, the optical deflector includes a phase modulation element array having phase modulation elements arranged two-dimensionally in the switch direction and the spectral direction. A periodic phase modulation is applied to the phase modulation element to form a phase modulation pattern in the phase modulation element array, and the pattern is desired for the optical signal input to the phase modulation element array. And diffracting so as to be coupled to the input / output optical fiber array.

  Also, in the control method of the optical signal selection device according to the present invention as set forth in the invention described above, the first switching step is configured such that the pattern is changed from the first pattern that outputs the optical signal to the first output port. Is a first pattern switching step of switching to a relay pattern that outputs to the relay position, and the second switching step includes outputting the pattern to the relay pattern or the optical signal to the other relay position. A second pattern switching step of switching from the relay pattern to a second pattern for outputting the optical signal to the second output port.

  In the control method of the optical signal selection device according to the present invention, in the above invention, the first pattern switching step or the second pattern switching step is within one period in the spectral direction of the periodic phase modulation. The step of switching from the pre-switching pattern to the post-switching pattern over time, one column at a time along the switch direction.

  In the control method of the optical signal selection device according to the present invention as set forth in the invention described above, the first pattern switching step or the second pattern switching step sends the optical signal from the first output port to the relay position. It is a step of changing the pattern stepwise or switching the pattern so that the optical signal is displaced stepwise from the relay position or the other relay position to the second output port.

  In the control method of the optical signal selection device according to the present invention, in the above invention, the first pattern switching step or the second pattern switching step is within one period in the spectral direction of the periodic phase modulation. When there are n phase modulation elements, there are a plurality of processes in which the amount of change in phase modulation in each phase modulation element per process is 2π / (n−1) or less.

  In the control method of the optical signal selection device according to the present invention, in the above invention, the first pattern switching step or the second pattern switching step is within one period in the spectral direction of the periodic phase modulation. In each of the above, the phase modulation elements of the phase modulation elements in the switch direction start phase modulation over time from the columns where the amount of change in phase modulation between the pattern before switching and the pattern after switching is large. To do.

  In the control method of the optical signal selection device according to the present invention, in the above invention, the first pattern switching step or the second pattern switching step is within one period in the spectral direction of the periodic phase modulation. The phase modulation switching is started simultaneously for each column along the switch direction of the phase modulation element, and the phase modulation switching is finished in the order of the predetermined phase for each column. To do.

  Further, in the control method of the optical signal selection device according to the present invention, in the above invention, the control device includes a storage unit that stores parameters used for control, the control unit reads the parameters from the storage unit, and The optical deflector is controlled.

  The optical signal selection device according to the present invention includes an input / output optical fiber array in which a plurality of optical fibers are arranged along a predetermined switch direction, and an optical signal input from the input / output optical fiber array as the switch direction. A wavelength spectrometer that splits the light in a substantially vertical direction, an optical deflector that reflects the split optical signal at a predetermined angle and couples it to a desired input / output optical fiber array, and the optical signal of the optical deflector A control device including a control unit that controls an angle at which light is reflected, and an optical signal selection device that outputs the input optical signal from a desired input / output optical fiber array, wherein the control device includes: When switching the input / output optical fiber array to be output from the first output port to the second output port, the optical deflector is configured so that the reflection direction of the optical signal at the optical deflector is directed to the first output port. From the direction, the first switching step to switch from the direction to the relay position separated from the straight line on which the input / output optical fiber array is arranged, and the optical deflector from the direction to the relay position or another relay position, A control including a second switching step for switching in the direction with respect to the second output port is performed, and the first switching step and the second switching step each include a plurality of stepwise steps.

  The optical signal selection device according to the present invention is the phase modulation element array according to the above invention, wherein the optical deflector includes phase modulation elements arranged two-dimensionally in the switch direction and the spectral direction. The phase modulation element array applies periodic phase modulation to the phase modulation element to form a phase modulation pattern in the phase modulation element array, and the pattern is input to the phase modulation element array. The optical signal is diffracted to be coupled to a desired input / output optical fiber array.

  In the optical signal selection device according to the present invention, in the above invention, the first switching step relays the optical signal from the first pattern that outputs the optical signal to the first output port. A first pattern switching step of switching to a relay pattern that is output to a position, wherein the second switching step is to output the pattern, the relay pattern, or another relay pattern that outputs the optical signal to the other relay position. To a second pattern switching step for switching to the second pattern for outputting the optical signal to the second output port.

  Moreover, the optical signal selection device according to the present invention is the above invention, wherein the first pattern switching step or the second pattern switching step is performed within one period in the spectral direction of the periodic phase modulation. It is a step of switching from a pre-switching pattern to a post-switching pattern over time, one column at a time along the switch direction.

  The optical signal selection device according to the present invention is the optical signal selection device according to the above invention, wherein the first pattern switching step or the second pattern switching step is stepwise from the first output port to the relay position. It is a step of changing the pattern so that the optical signal is displaced stepwise from the relay position or the other relay position to the second output port.

  The optical signal selection device according to the present invention is the optical signal selection device according to the above invention, wherein the number of the first pattern switching step or the second pattern switching step is n in one cycle in the spectral direction of the periodic phase modulation. When there are two phase modulation elements, the amount of change in phase modulation in each phase modulation element per process is composed of a plurality of processes of 2π / (n−1) or less.

  Moreover, the optical signal selection device according to the present invention is the above invention, wherein the first pattern switching step or the second pattern switching step is performed within one period in the spectral direction of the periodic phase modulation. Phase modulation of each column along the switch direction of the phase modulation element is started over time from the column having a large amount of phase modulation change between the pattern before switching and the pattern after switching.

  Moreover, the optical signal selection device according to the present invention is the above invention, wherein the first pattern switching step or the second pattern switching step is performed within one period in the spectral direction of the periodic phase modulation. The phase modulation switching is started at the same time for each column along the switch direction of the phase modulation element, and the phase modulation switching is finished in the order in which each column has a predetermined phase.

  The optical signal selection device according to the present invention is the optical signal selection device according to the above invention, wherein the control device includes a storage unit that stores parameters used for control, the control unit reads the parameters from the storage unit, and the optical deflector It is characterized by controlling.

  ADVANTAGE OF THE INVENTION According to this invention, the control method of an optical signal selection apparatus and the optical signal selection apparatus which suppressed generation | occurrence | production of the crosstalk at the time of switching the input-output optical fiber array which outputs an optical signal are realizable.

FIG. 1 is a schematic configuration diagram of an optical signal selection device to which a control method according to an embodiment of the present invention is applied. FIG. 2 is a diagram illustrating a state in which an optical signal is incident on the phase modulation element array. FIG. 3 is a diagram for explaining a phase pattern of the phase modulation element array when the path of the optical signal is switched. FIG. 4 is a diagram of FIG. 3 viewed from the phase axis direction. FIG. 5 is a view of FIG. 3 viewed from the X-axis (spectral axis) direction. FIG. 6 is a diagram for explaining a method of switching the output destination of an optical signal. FIG. 7 is a diagram for explaining an example of an optical signal output destination switching method in which the occurrence of crosstalk is suppressed. FIG. 8 is a diagram of the phase pattern of the phase modulation element array at the relay position viewed from the X-axis (spectral axis) direction in the method of switching the output destination of the optical signal in which the occurrence of crosstalk is suppressed. FIG. 9 is a diagram illustrating the phase pattern of the phase modulation element array at the relay position in the method of switching the output destination of the optical signal in which the occurrence of crosstalk is suppressed. FIG. 10 is a diagram for explaining a control method of the optical signal selection device according to the embodiment of the present invention. FIG. 11 is a diagram of the phase pattern of the phase modulation element array in FIG. 10 viewed from the X-axis (spectral axis) direction. FIG. 12 is a diagram for explaining a control method of the optical signal selection device according to the first modification. FIG. 13 is a diagram of the phase pattern of the phase modulation element array in FIG. 12 viewed from the X-axis (spectral axis) direction. FIG. 14 is a diagram for explaining a control method of the optical signal selection device according to the second modification. FIG. 15 is a diagram of the phase pattern of the phase modulation element array in FIG. 14 viewed from the X-axis (spectral axis) direction. FIG. 16 is a diagram for explaining a control method of the optical signal selection device according to the third modification. FIG. 17 is a diagram of the phase pattern of the phase modulation element array in FIG. 16 as viewed from the X-axis (spectral axis) direction. FIG. 18 is a diagram for explaining an example of a method of switching the output destination of an optical signal in which the occurrence of crosstalk is suppressed. FIG. 19 is a diagram for explaining an example of an optical signal output destination switching method in which the occurrence of crosstalk is suppressed.

  Embodiments of an optical signal selection device control method and an optical signal selection device according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments. In the description of the drawings, the same or corresponding elements are appropriately denoted by the same reference numerals. Also, it should be noted that the drawings are schematic, and the relationship between the dimensions of each element, the ratio of each element, and the like may differ from the actual situation. Even between the drawings, there are cases in which portions having different dimensional relationships and ratios are included.

(Embodiment)
FIG. 1 is a schematic configuration diagram of an optical signal selection device to which a control method according to an embodiment of the present invention is applied. The optical signal selection device 100 includes an input / output optical fiber array 10, a wavelength spectrometer 20, a condenser lens 30, a phase modulation element array 40, and a control device 50. Here, for the sake of explanation, XY coordinate axes are defined parallel to the element surface of the phase modulation element array 40. The X axis is appropriately described as a spectral axis or an X axis (spectral axis), and the Y axis is described as a switch axis or an appropriate Y axis (switch axis).

The input / output optical fiber array 10 includes a plurality of optical fibers 11 _{1 to} 11 _m arranged in an array along the Y-axis direction. For example, m may be an integer of 3 or more, and may be one optical input port and two or more optical output ports. Ferrules 12 _{1 to} 12 _m with a collimator lens are attached to the respective tips of the optical fibers 11 _{1 to} 11 _m . Optical fiber 11 ₁ functions as an optical input port, an optical fiber ₁₁ 2 to 11 _m functions as an optical output port.

  The wavelength spectrometer 20 is configured using, for example, a diffraction grating. The wavelength spectrometer 20 is arranged so as to split the optical signal input from the input / output optical fiber array 10 along the X-axis direction.

  The condensing lens 30 is disposed so as to condense the light dispersed by the wavelength spectrometer 20 onto the phase modulation element array 40.

  The phase modulation element array 40 includes unit phase modulation elements (pixels) that can change the refractive index by applying a voltage and are arranged two-dimensionally on the XY plane. The phase modulation element array 40 can be configured using, for example, a reflective LCOS that uses a liquid crystal element as a phase modulation element.

  The control device 50 includes a control unit 51. The control unit 51 is connected to the phase modulation element array 40 and is configured to apply a desired voltage to each phase modulation element constituting the phase modulation element array 40. Furthermore, the control device 50 may include a storage unit 52 that stores parameters used for control. Thereby, the control part 51 can read the optimal method of control from the memory | storage part 52, and can function.

Next, the operation of the optical signal selection device 100 will be described. First, the optical fiber 11 ₁ in the input and output optical fiber array 10 to input optical signal _{S 1,} S 2, _{S n} from the outside. Here, n is an integer of 3 or more and less than m. Optical signals _{S 1, S 2, S n} have different wavelengths from each other, are assigned to different channels of a WDM optical signal. Wavelength of the optical signal _{S 1, S 2, S n} is the wavelength used for optical communication, for example in the range of 1520 nm to 1620 nm. Optical signals _{S 1, S 2, S n} is collimated by the ferrule 12 ₁ of the collimator lens.

Optical signals _{S 1, S 2, S n} propagates along an optical path indicated by a thick solid line, incident on the wavelength spectroscope 20. Wavelength spectrometer 20 is the optical signal S _1, S _2, S _n the diffracted at different diffraction angles according to the respective wavelengths, spectrally three optical signals.

The condensing lens 30 condenses the optical signal S ₁ propagating along the optical path indicated by the broken line on the phase modulation element array 40. Phase modulating element array 40 diffracts light signals S ₁ incident is condensed at a predetermined angle. This diffraction angle is controlled by the control device 50.

Diffracted light signals S ₁ is collimated by the condenser lens 30, is input to a desired optical fiber 11 _k through the ferrule 12 _k by the wavelength spectroscope 20. As a result, switching of the path of the optical signal S _{1 from} the optical fiber 11 ₁ to the optical fiber 11 _k is realized.

Similarly, condenses each converging lens 30 is a dotted line, an optical signal S _2, S _n propagating along an optical path indicated by a chain line in the phase modulating element array 40. The phase modulation element array 40 diffracts the incident and incident optical signals S ₂ and _Sn at a predetermined angle. Diffraction angle of the light signals S _2, S _n are different from each other, and also different from the diffraction angle of the optical signal S _1. The diffracted optical signals S ₂ and _Sn are converted into parallel light by the condenser lens 30 and input to the desired optical fibers 11 _l and 11 _m by the wavelength spectrometer 20 via the ferrules 12 _l and 12 _m , respectively. As a result, switching of the paths of the optical signals S ₂ and _{Sn from} the optical fiber 11 ₁ to the optical fibers 11 _l and 11 _m is realized.

Next, specifically described diffraction of light signals _{S 1, S 2, S n} by the phase modulating element array 40. FIG. 2 is a diagram illustrating a state where the optical signals S ₁ , S ₂ , and _Sn are incident on the phase modulation element array 40. As shown in FIG. 2, the optical signals S _1, S _2, S _n are incident on different regions of the phase modulation element array 40 along the X-axis (spectral axis). Further, the optical signals S _1, S _2, S _n is incident beam is spread over a plurality of phase modulating elements.

Figure 3 is a diagram for explaining a phase pattern of the phase modulating element array 40 in the case of switching of the optical signals S _1, S _2, S _n route. As shown in FIG. 3, of the phase modulating element array 40, the optical signal _{S 1, S 2, S n} each region is incident _{A 1, A 2, A n} is along the Y-axis (the switch shaft) A linear periodic phase modulation having a different inclination is applied to form a phase modulation pattern in the phase modulation element array 40.

  FIG. 4 is a diagram of FIG. 3 viewed from the phase axis direction. In FIG. 4, the phase changes stepwise along the Y axis (switch axis) because the phase modulation is discretized by the pixel, and the linear phase of FIG. 3 and FIG. Modulation is a linear approximation of stepped phase modulation. Thus, applying linear phase modulation includes the case of applying stepwise periodic phase modulation that can be linearly approximated.

FIG. 5 is a view of FIG. 3 as viewed from the X-axis direction. Linear phase modulation applied to the phase modulation element array 40 and the incident angle and emission angle of the optical signal with respect to the element surface of the phase modulation element array 40 The relationship is shown. The conditions for obtaining the desired diffraction angle θ _Yout can be expressed by the following equation (1).

In equation (1), Δφ _Y is a necessary phase modulation gradient, distance d _Y is the phase modulation period, λ is the wavelength of the optical signal, and angle θ _Yin is the incident angle of the optical signal. If the wavelength of the optical signal has a spectral spread, λ may be the center wavelength of the wavelength band of the optical signal, for example. In FIG. 5, the phase change is from 0 to 2π, and the reason why the phase change is sawtooth is that the phase is a periodic function from 0 to 2π. This is because even if the phase is set so as to be folded in the range of 2π, the same phase characteristic is obtained.

Therefore, when performing switching of optical signals _{S 1, S 2, S n} path, the control device 50, the wavelength of the optical signal _{S 1, S 2, S n,} the angle of incidence, depending on the desired diffraction angle as the optical signals _{S 1,} S 2, of the phase modulation for _{S n} slope [Delta] [phi _Y is obtained, controls the phase of the phase modulation element of each region _{a 1, a 2, a n} of the phase modulating element array 40 . In this way, by applying periodic phase modulation to the phase modulation elements of the phase modulation element array 40, a phase modulation pattern is formed on the phase modulation element array 40, and the phase modulation element is appropriately formed to form the phase modulation element. Optical signals input to the array 40 can be diffracted to couple to the desired input / output optical fiber array.

Here, in this optical signal selection device 100, as an output port switching step, for example, by changing the phase pattern of the phase modulation element array 40, for example, an input / output optical fiber array that outputs an optical signal _Sn is output to the first output. port from the optical fiber 11 _m is, the operation will be described of switching the optical fiber 11 _l is a second output port.

First, FIG. 6 is a diagram for explaining a method of switching the output destination of an optical signal. FIG. 6 is a view of the phase modulation element array 40 as viewed from the wavelength spectrometer 20 side. As shown in FIG. 6, switching the output port from the optical fiber 11 _m to the optical fiber 11 _l means that the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 is the center of the ferrule 12 _m. The displacement is from P _0m to the position P _0l which is the center of the ferrule 12 _l . Thus, changing the reflecting direction of the phase modulating element array 40 of the optical signal S _n in order to an appropriate value [Delta] [phi _Y of formula (1), brought into appropriately changing the pattern of the phase modulating element array 40 That's fine.

Thus when switching the output port from the optical fiber 11 _m to the optical fiber 11 _l, as the route _{R 1} shown in FIG. 6, when the optical signal _{S n} passes the position _{P 0k} is the center of the ferrule 12 _k, It becomes a part of the optical signal S _n is output from the optical fiber 11 _k, so that the crosstalk occurs. When the input / output optical fiber array 10 includes one optical input port and two optical output ports, such crosstalk occurs when the optical input port is disposed between the two optical output ports. Will end up.

Next, FIG. 7 is a diagram illustrating an example of a method for switching the output destination of an optical signal in which the occurrence of crosstalk is suppressed. As shown in FIG. 7, the output port switching step in the control method of the optical signal selector according to the present embodiment, to displace the reflecting direction of the phase modulating element array 40 of the optical signal S _n along the path R _2. Route _{R 2} from the direction of the position _{P 0 m} with respect to the optical fiber 11 _m, which is the first output port, via the position _{P 1 m} and the position _{P 1l} is a relay position, with respect to the optical fiber 11 _l is a second output port This is a path to be displaced to the position P _{0l in the} direction.

Here, the position P _1m and the position P ₁₁ which are the relay positions are positions separated from the straight line on which the input / output optical fiber array 10 is arranged. By a path through such a relay position, the output port switching step, the optical signal S _n does not pass through the port switching other than the front and rear output ports, such as optical fiber 11 _k. However, in the phase modulation element array 40 having two-dimensionally arranged phase modulation elements, crosstalk may occur accidentally when the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 is switched. is there. Switching the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 means changing the pattern of the phase modulation element array 40 as described above. This is due to, for example, changing the voltage applied to each phase modulation element of the phase modulation element array 40 which is a reflective liquid crystal element. Thereby, the phase modulation amount of each phase modulation element continuously changes from the phase modulation amount before switching to the phase modulation amount after switching. At this time, an unintended pattern occurs during switching. This unintended pattern, an optical signal S _n is reflected in an unintended direction, accidentally some cases cross-talk may occur. In particular, when a reflective LCOS using a liquid crystal element is used as the phase modulation element array 40, the response of the liquid crystal element to the applied voltage has a large time constant of several hundreds msec, and if the phase change amount is large, the switching is not intended. It takes longer time to become a pattern. As a result, accidental crosstalk is more likely to occur. Therefore, in the control method of the optical signal selection device according to the present embodiment, the pattern of the phase modulation element array 40 is switched stepwise to suppress the occurrence of crosstalk.

Next, a specific control method of the phase modulation element array 40 in the output port switching step of the control method of the optical signal selection device according to the present embodiment will be described. First, FIG. 8 is a diagram of the phase pattern of the phase modulation element array at the relay position viewed from the X-axis (spectral axis) direction in the optical signal output destination switching method in which the occurrence of crosstalk is suppressed. As shown in FIG. 8, when linear periodic phase modulation is applied to the phase modulation element array 40 also in the X-axis direction, the reflection of the optical signal _{Sn in} the phase modulation element array 40 as in the Y-axis direction of FIG. The direction can be controlled. Thus, the optical signal _{S n} is incident at an angle _{theta Xin} to the phase modulating element array 40 is diffracted by the phase modulating element array 40 in the direction of the angle _{theta Xout.} The conditions for obtaining the desired diffraction angle θ _Xout can be expressed by the following equation (2) as in the equation (1).

In Expression (2), Δφ _X is a necessary phase modulation gradient, and distance d _X is a phase modulation period. FIG. 9 is a diagram illustrating the phase pattern of the phase modulation element array at the relay position in the method of switching the output destination of the optical signal in which the occurrence of crosstalk is suppressed. FIG. 9A shows a first pattern of the phase modulation element array 40 for setting the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 to a position P _0m that is a direction with respect to the optical fiber 11 _m . FIG. 9B is a relay pattern of the phase modulation element array 40 for setting the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 to a position P _1m that is a direction with respect to the relay position. That is, in the phase modulation element array 40, the first pattern having the linear periodic phase modulation in the Y-axis direction shown in FIG. 5 shown in FIG. 9A and the linearity in the X-axis direction shown in FIG. In order to add the periodic phase modulation, a relay pattern as shown in FIG. In this way, by changing the first pattern of FIG. 9A to the relay pattern of FIG. 9B, the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 is changed from the position P _0m to the position P _1m . And can be switched. As described above, in the output port switching step of the control method of the optical signal selection device according to the present embodiment, the first switching step switches the first pattern in FIG. 9A to the relay pattern in FIG. 9B. It may be a first pattern switching step. Thereafter, the slope of the phase modulation in the Y-axis direction is changed, and the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 is switched from the position P _1m to the position P ₁₁ . Further, the phase modulating element array 40 and the second pattern from the relay pattern as a second switching step, the reflecting direction of the phase modulating element array 40 of the optical signal S _n, the second pattern switching for switching to the position P _0l from the position P _1l Perform the process. Thus, as shown in FIG. 7, without passing through a port other than the optical signal S _n is the optical fiber 11 before and after the switching _m and the optical fiber 11 _l, it is possible to switch the output port.

Here, when the voltage applied from the control device to the phase modulation element array 40 is changed when the first pattern in FIG. 9A is switched to the relay pattern in FIG. 9B, the optical signal of each phase modulation element is changed. The magnitude of the phase modulation with respect to changes. At this time, for example, the phase modulation element, which is a reflective liquid crystal element, continuously changes the phase modulation amount from the phase modulation amount before switching to the phase modulation amount after switching. Therefore, while switching the first pattern of FIG. 9A to the relay pattern of FIG. 9B, the pattern of a certain phase modulation element array 40 is the first pattern of FIG. 9A and FIG. This is an unintended pattern between the relay pattern of b). This unintended pattern may reflect the optical signal S _n in an unintended direction. By reflection of an unintended direction of the optical signal S _n, the portion of the optical signal S _n is incident in addition to the desired output port, such as an optical fiber 11 _k, so that the crosstalk occurs.

  Generation of crosstalk due to an unintended pattern of the phase modulation element array 40 when switching such a pattern can be suppressed by performing pattern switching stepwise. For example, by performing pattern switching step by step, the overall phase change amount for each pattern switching can be reduced, and the time for an unintended pattern can be shortened to suppress crosstalk. Such an effect becomes more conspicuous when a liquid crystal element having a slow response to the applied voltage is used as the phase modulation element array 40. That is, the occurrence of such crosstalk is suppressed by performing the first switching step and the second switching step in the output port switching step of the control method for the optical signal selection device according to the present embodiment stepwise. Can do.

  FIG. 10 is a diagram for explaining a control method of the optical signal selection device according to the embodiment of the present invention. As shown in FIG. 10, the first pattern switching step in the output port switching step of the control method for the optical signal selection device according to the present embodiment is performed in the phase modulation element array 40 in the X-axis direction of periodic phase modulation ( This is a step of switching from the first pattern before switching over time to the relay pattern after switching one column at a time along the Y-axis direction (switching direction) within one cycle in the (spectral direction).

As shown in FIG. 10, it is assumed that one cycle in the X-axis direction includes four rows of phase modulation elements. First, as shown in FIG. 10A, there is no phase modulation component in the X-axis direction at time t = 0. First, as shown in FIG. 10 (b), at time t = 0 to t _1, the phase modulation of the phase modulation element of the second column from the left is switched. Next, as shown in FIG. 10C, the phase modulation of the phase modulation elements in the third column from the left is switched at time t = t _{1 to} t ₂ . Then, as shown in FIG. 10D, the phase modulation of the phase modulation elements in the fourth column from the left is switched from time t = t _{2 to} t ₃ .

FIG. 11 is a diagram of the phase pattern of the phase modulation element array in FIG. 10 viewed from the X-axis (spectral axis) direction. When the stepwise phase modulation of FIG. 10 is linearly approximated as shown in FIG. 5, FIG. 11 is obtained. Thus, the first switching process can be made a step-by-step process by changing the pattern of the phase modulation element array 40 by one column along the Y-axis direction. At this time, an unintended pattern is less likely to occur than when the pattern of the phase modulation element array 40 is changed from the first pattern to the relay pattern in one step as shown in FIG. That is, by performing the pattern switching step by step, the overall phase change amount for each pattern switching is reduced, and the time for an unintended pattern is shortened to suppress the occurrence of crosstalk. Therefore, the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 becomes an unintended direction, and the occurrence of crosstalk can be suppressed. Therefore, the control method of the optical signal selection device according to the present embodiment is a control method of the optical signal selection device that suppresses the occurrence of crosstalk when the input / output optical fiber array that outputs the optical signal is switched.

  Furthermore, in the optical signal selection device 100 according to the present embodiment, the storage unit 52 in the control device 50 stores parameters for modulating the pattern of the phase modulation element array 40 step by step, and the control unit 51 stores the parameters. And the phase modulation element array 40 is controlled to suppress the occurrence of crosstalk. Therefore, the optical signal selection device 100 according to the present embodiment is an optical signal selection device that suppresses the occurrence of crosstalk when switching input / output optical fiber arrays that output optical signals.

Similarly to the first switching step, the second switching step generates crosstalk by changing the pattern of the phase modulation element array 40 one by one along the Y-axis direction from the relay pattern to the second pattern. Can be suppressed. Also, switching to the position P _1l from the position P _{1 m} in Fig. 7, since the displacement at sufficiently spaced position from the straight line arranged in the input and output optical fiber array 10, by an unintended pattern occurs, crosstalk Is extremely low. Therefore, switching from the position P _1m to the position P _1l can reduce the switching time by switching the pattern of the phase modulation element array 40 in one step.

(Modification 1)
Next, a control method for an optical signal selection device and an optical signal selection device according to Modification 1 of the present invention will be described. FIG. 12 is a diagram for explaining a control method of the optical signal selection device according to the first modification. As shown in FIG. 12, the control method of the optical signal selector according to the first modification, the first pattern switching step, an optical signal S _n in a direction with respect to the relay position from the position P _{0 m} is a direction to the first output port This is a step of gradual displacement to a certain position P _{1 m} .

As shown in FIG. 12, it is assumed that one period in the X-axis direction includes four rows of phase modulation elements. First, as shown in FIG. 12A, there is no phase modulation component in the X-axis direction at time t = 0. First, as shown in FIG. 12 (b), at time t = 0 to t _1, the maximum value applies a linear periodic phase modulation so that 2 [pi / 3. Next, as shown in FIG. 12C, linear periodic phase modulation is applied so that the maximum value is 4π / 3 at time t = t _{1 to} t ₂ . Then, as shown in FIG. 12D, linear periodic phase modulation is applied so that the maximum value becomes 2π at time t = t _{2 to} t ₃ . That is, this corresponds to stepwise displacement of the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 from the position P _0m to the position P _1m .

FIG. 13 is a diagram of the phase pattern of the phase modulation element array in FIG. 12 viewed from the X-axis (spectral axis) direction. FIG. 13 is obtained by linearly approximating the stepwise phase modulation of FIG. 12 as shown in FIG. As described above, the first switching step is changed stepwise by changing the gradient of the linear periodic phase modulation in the X axis direction stepwise, that is, by displacing the displacement in the X axis direction stepwise. be able to. At this time, an unintended pattern is less likely to occur than when the pattern of the phase modulation element array 40 is changed from the first pattern to the relay pattern in one step as shown in FIG. That is, by performing the pattern switching step by step, the overall phase change amount for each pattern switching is reduced, and the time for an unintended pattern is shortened to suppress the occurrence of crosstalk. Therefore, the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 becomes an unintended direction, and the occurrence of crosstalk can be suppressed. Therefore, the control method of the optical signal selection device according to the first modification is a control method of the optical signal selection device that suppresses the occurrence of crosstalk when the input / output optical fiber array that outputs the optical signal is switched.

  In Modification 1, the maximum value of linear periodic phase modulation applied in each step as shown in FIG. 12 can be arbitrarily set. Therefore, it is possible to realize a method of controlling an optical signal selection device that reduces the amount of change in phase modulation per process and suppresses the occurrence of crosstalk when switching input / output optical fiber arrays that output more optical signals. .

(Modification 2)
Next, a control method for an optical signal selection device and an optical signal selection device according to Modification 2 of the present invention will be described. FIG. 14 is a diagram for explaining a control method of the optical signal selection device according to the second modification. As shown in FIG. 14, in the control method of the optical signal selection device according to the second modification, the first pattern switching step is performed in the phase modulation element array 40 with 1 in the X-axis direction (spectral direction) of periodic phase modulation. When there are n phase modulation elements in a cycle, the process includes a plurality of processes in which the amount of change in phase modulation in each phase modulation element per process is 2π / (n−1) or less. Further, in the phase modulation element array 40, the first pattern switching step includes each phase along the Y-axis direction (switch direction) of the phase modulation element within one period in the X-axis direction (spectral direction) of periodic phase modulation. Phase modulation is started over time from a column in which the amount of change in phase modulation between the first pattern before switching and the relay pattern after switching is large.

As shown in FIG. 14, it is assumed that one period in the X-axis direction is composed of four rows of phase modulation elements. At this time, the amount of change in phase modulation between the first pattern and the relay pattern is larger in the right column in one cycle in the X-axis direction. First, as shown in FIG. 14A, there is no phase modulation component in the X-axis direction at time t = 0. First, as shown in FIG. 14B, at time t = 0 to t ₁ , phase modulation of 2π / 3 is performed in the fourth column from the left having the largest amount of change in phase modulation between the first pattern and the relay pattern. Apply. Next, as shown in FIG. 14C, at time t = t _{1 to} t ₂ , 2π / 3 phase modulation is further applied to the fourth column from the left, and the phase between the first pattern and the relay pattern A phase modulation of 2π / 3 is applied to the third column from the left with the second largest change in modulation. Then, at time t = t _{2 to} t ₃ , as shown in FIG. 14D, the phase modulation of 2π / 3 is further applied to the third and fourth columns from the left, and the first pattern and the relay pattern are A phase modulation of 2π / 3 is applied to the second column from the left where the amount of change in phase modulation is the third largest. As described above, in each column of phase modulation elements, the amount of change in phase modulation per process is 2π / (n−1) or less, and the amount of change in phase modulation per process can be reduced. The effect which suppresses becomes remarkable.

FIG. 15 is a diagram of the phase pattern of the phase modulation element array in FIG. 14 viewed from the X-axis (spectral axis) direction. FIG. 15 is obtained by linearly approximating the phased phase modulation of FIG. 14 as shown in FIG. Thus, in the X-axis direction, phase modulation is started in order from the column with the largest phase modulation, and the amount of change per process is set to 2π / (n−1) or less, so that the first switching process is stepwise. It can be a process, and the amount of change in phase modulation of each phase modulation element in each process can be reduced. As a result, an unintended pattern is generated, the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 becomes an unintended direction, and the effect of suppressing the occurrence of crosstalk becomes more remarkable. Therefore, the control method of the optical signal selection device according to the second modification is a control method of the optical signal selection device that suppresses the occurrence of crosstalk when the input / output optical fiber array that outputs the optical signal is switched.

(Modification 3)
Next, a control method for an optical signal selection device and an optical signal selection device according to Modification 3 of the present invention will be described. FIG. 16 is a diagram for explaining a control method of the optical signal selection device according to the third modification. As shown in FIG. 16, in the control method of the optical signal selection device according to the third modification, the first pattern switching step is performed in the phase modulation element array 40 with 1 in the X-axis direction (spectral direction) of periodic phase modulation. When there are n phase modulation elements in a cycle, the process includes a plurality of processes in which the amount of change in phase modulation in each phase modulation element per process is 2π / (n−1) or less. Further, in the phase modulation element array 40, the first pattern switching step includes each phase along the Y-axis direction (switch direction) of the phase modulation element within one period in the X-axis direction (spectral direction) of periodic phase modulation. At the same time, the switching of the phase modulation is started for the columns, and the switching of the phase modulation is finished in the order in which each column has a predetermined phase.

As shown in FIG. 16, it is assumed that one period in the X-axis direction includes four rows of phase modulation elements. First, as shown in FIG. 16A, there is no phase modulation component in the X-axis direction at time t = 0. First, as shown in FIG. 16 (b), at time t = 0 to t _1, the leftmost column will not be changing the phase modulation from the phase modulation is zero in the relay pattern after switching. The phase modulation of 2π / 3 is applied to the second to fourth columns from the left. Next, as shown in FIG. 16C, at the time t = t _{1 to} t ₂ , the second column from the left has the same phase modulation as the relay pattern after switching, so the phase modulation is not changed. . On the other hand, since the third and fourth columns from the left do not have the same phase modulation as the relay pattern after switching, 2π / 3 phase modulation is further applied. Then, as shown in FIG. 16D, since the third column from the left has the same phase modulation as the relay pattern after switching at time t = t _{2 to} t ₃ , the phase modulation is not changed. On the other hand, since the fourth column does not have the same phase modulation as that of the relay pattern after switching, 2π / 3 phase modulation is further applied. In this way, in each column of phase modulation elements, the amount of change in phase modulation per process is 2π / (n−1) or less, and the amount of change per process can be reduced, thereby further suppressing crosstalk. The effect to do becomes remarkable.

FIG. 17 is a diagram of the phase pattern of the phase modulation element array in FIG. 16 as viewed from the X-axis (spectral axis) direction. When the stepwise phase modulation of FIG. 16 is linearly approximated as shown in FIG. 5, FIG. 17 is obtained. As described above, the first switching step is performed by starting the phase modulation all at once, ending the phase modulation from the column having the desired phase, and setting the amount of change per step to 2π / (n−1) or less. Can be a stepwise process, and the amount of change in phase modulation of each phase modulation element in each process can be reduced. As a result, an unintended pattern is generated, the reflection direction of the optical signal _{Sn in} the phase modulation element array 40 becomes an unintended direction, and the effect of suppressing the increase in crosstalk becomes more remarkable. Therefore, the control method of the optical signal selection device according to the third modification is a control method of the optical signal selection device that suppresses the occurrence of crosstalk when the input / output optical fiber array that outputs the optical signal is switched.

  As described above, according to the present embodiment, a method for controlling an optical signal selection device and an optical signal selection device that suppress the occurrence of crosstalk when switching input / output optical fiber arrays that output optical signals are provided. can do.

  In the present embodiment, the first switching process is described, and the description of the second switching process is omitted. However, the second switching process is performed by a plurality of step-by-step processes in the reverse order of the first switching process. can do. Further, the first switching step and the second switching step may be a combination of different steps between the embodiment and the first to third modifications.

In the present embodiment, as shown in FIG. 7, the first switching step and the second switching step are displaced only in the X-axis direction, but the present invention is not limited to this. 18 and 19 are diagrams for explaining an example of a method of switching the output destination of an optical signal in which the occurrence of crosstalk is suppressed. As shown in FIG. 18, the route R ₃ is a relay position position P 'may have a displacement in the Y-axis direction. Further, as shown in FIG. 19, the route R ₄ is displaced to the displacement and Y-axis direction in the X-axis direction may be performed alternately. Also in this case, by performing the change to each position stepwise, it is possible to realize the control method of the optical signal selection device that suppresses the occurrence of crosstalk when switching the input / output optical fiber array that outputs the optical signal. .

  In the above embodiment, the case where the phase modulation component in the X-axis direction in the initial state is zero has been described, but the present invention is not limited to this. That is, even when a predetermined phase modulation is applied in the X-axis direction in the initial state, the crosstalk is changed by stepwise switching the phase pattern of the phase modulation element array as in the above embodiment. Can be suppressed. For example, when a predetermined phase modulation is applied in the X-axis direction in the initial state, the phase pattern of the phase modulation element array is switched stepwise as in the above embodiment, and the phase modulation in the X-axis direction is zero. Then, phase modulation is applied in the Y-axis direction, and predetermined phase modulation is again applied stepwise in the X-axis direction. Thus, even when a predetermined phase modulation is applied in the X-axis direction in the initial state, an optical signal selection device that suppresses the occurrence of crosstalk when switching input / output optical fiber arrays that output optical signals The control method can be realized.

  Further, the present invention is not limited by the above embodiment. What was comprised combining each component mentioned above suitably is also contained in this invention. Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

10 input and output optical fiber arrays 11 ₁ to 11 _m optical fiber 12 ₁ to 12 _m ferrule 20 wavelength spectroscope 30 converging lens 40 phase modulating element array 50 control device 51 control unit 52 storage unit 100 optical signal selecting device A _1, A _{2, A n} region d _{X, d Y} distance _{P 0l, P 0k, P 0m} , P 1l, P 1m, P ' positions _{R 1, R 2, R 3} , R 4 path _{S 1,} S 2, S _n light Signals t, t ₁ , t ₂ , t ₃ hours θ _Xin , θ _Xout , θ _Yin , θ _Yout angles

Claims (18)

An input / output optical fiber array in which a plurality of optical fibers are arranged along a predetermined switch direction;
A wavelength spectrometer that splits an optical signal input from the input / output optical fiber array in a direction substantially perpendicular to the switch direction;
An optical deflector that reflects the dispersed optical signal at a predetermined angle and couples it to a desired input / output optical fiber array;
A control device comprising a control unit for controlling an angle at which the optical signal of the optical deflector is reflected;
In the optical signal selection device for outputting the input optical signal from a desired input / output optical fiber array, output port switching for switching the output input / output optical fiber array from the first output port to the second output port A method of controlling an optical signal selection device including a process,
The output port switching step switches the reflection direction of the optical signal at the optical deflector from the direction with respect to the first output port to the direction with respect to a relay position separated from the straight line on which the input / output optical fiber array is arranged. Including a first switching step and a second switching step for switching from the direction with respect to the relay position or another relay position to the direction with respect to the second output port, wherein the first switching step and the second switching step are respectively A method for controlling an optical signal selection device comprising a plurality of stepwise steps. The optical deflector is a phase modulation element array having phase modulation elements arranged two-dimensionally in the switch direction and the spectral direction,
Periodic phase modulation is applied to the phase modulation element to form a phase modulation pattern in the phase modulation element array, and the pattern converts the optical signal input to the phase modulation element array into desired input / output light. 2. The method of controlling an optical signal selection device according to claim 1, wherein diffraction is performed so as to be coupled to the fiber array. The first switching step is a first pattern switching step of switching the pattern from a first pattern that outputs the optical signal to the first output port to a relay pattern that outputs the optical signal to the relay position. ,
The second switching step outputs the optical signal to the second output port from the relay pattern or another relay pattern that outputs the optical signal to the other relay position. The method for controlling an optical signal selection device according to claim 2, wherein the method is a second pattern switching step of switching to (1).   In the first pattern switching step or the second pattern switching step, one column along the switch direction is changed over time from the pattern before switching in one cycle in the spectral direction of the periodic phase modulation. 4. The method of controlling an optical signal selection device according to claim 3, wherein the control method is a step of switching to a pattern after switching.   In the first pattern switching step or the second pattern switching step, the optical signal is displaced stepwise from the first output port to the relay position, or the optical signal is shifted to the relay position or 4. The method of controlling an optical signal selection device according to claim 3, wherein the pattern switching step is a stepwise displacement from another relay position to the second output port.   In the first pattern switching step or the second pattern switching step, when there are n phase modulation elements in one period in the spectral direction of the periodic phase modulation, each phase modulation element per step The method of controlling an optical signal selection device according to claim 3, comprising a plurality of steps in which the amount of change in phase modulation at 2 is 2π / (n−1) or less.   In the first pattern switching step or the second pattern switching step, each column along the switch direction of the phase modulation element is switched before switching in one period in the spectral direction of the periodic phase modulation. 7. The method of controlling an optical signal selection device according to claim 6, wherein phase modulation is started over time from the column having a large amount of change in phase modulation between the pattern and the pattern after switching.   The first pattern switching step or the second pattern switching step is performed for each column along the switch direction of the phase modulation element within one period in the spectral direction of the periodic phase modulation. 7. The method of controlling an optical signal selection device according to claim 6, wherein the switching of the phase modulation is started at the same time, and the switching of the phase modulation is finished in the order of the predetermined phase for each column.   The said control apparatus is provided with the memory | storage part which stores the parameter used for control, The said control part reads the said parameter from the said memory | storage part, and controls the said optical deflector, The one of Claims 1-8 characterized by the above-mentioned. The control method of the optical signal selection apparatus as described in one. An input / output optical fiber array in which a plurality of optical fibers are arranged along a predetermined switch direction;
A wavelength spectrometer that splits an optical signal input from the input / output optical fiber array in a direction substantially perpendicular to the switch direction;
An optical deflector that reflects the dispersed optical signal at a predetermined angle and couples it to a desired input / output optical fiber array;
A control device comprising a control unit for controlling an angle at which the optical signal of the optical deflector is reflected;
An optical signal selection device for outputting the input optical signal from a desired input / output optical fiber array,
The control device changes the reflection direction of the optical signal in the optical deflector when the input / output optical fiber array to be output is switched from the first output port to the second output port. A first switching step so as to switch from a direction with respect to one output port to a direction with respect to a relay position separated from the straight line on which the input / output optical fiber array is arranged, and the optical deflector at the relay position or another relay position. And a second switching step for switching from the direction to the direction to the second output port, wherein the first switching step and the second switching step each include a plurality of stepwise steps. Optical signal selection device. The optical deflector is a phase modulation element array having phase modulation elements arranged two-dimensionally in the switch direction and the spectral direction,
The phase modulation element array applies periodic phase modulation to the phase modulation element to form a phase modulation pattern in the phase modulation element array, and the pattern is input to the phase modulation element array. 11. The optical signal selection device according to claim 10, wherein the signal is diffracted so as to be coupled to a desired input / output optical fiber array. The first switching step is a first pattern switching step of switching the pattern from a first pattern that outputs the optical signal to the first output port to a relay pattern that outputs the optical signal to the relay position. ,
The second switching step outputs the optical signal to the second output port from the relay pattern or another relay pattern that outputs the optical signal to the other relay position. 12. The optical signal selection device according to claim 11, which is a second pattern switching step of switching to.   In the first pattern switching step or the second pattern switching step, one column along the switch direction is changed over time from the pattern before switching in one cycle in the spectral direction of the periodic phase modulation. The optical signal selection device according to claim 12, wherein the optical signal selection device is a step of switching to a pattern after switching.   In the first pattern switching step or the second pattern switching step, the optical signal is displaced stepwise from the first output port to the relay position, or the optical signal is shifted to the relay position or 13. The optical signal selection device according to claim 12, wherein the optical signal selection device is a step of switching a pattern so as to be gradually displaced from another relay position to the second output port.   In the first pattern switching step or the second pattern switching step, when there are n phase modulation elements in one period in the spectral direction of the periodic phase modulation, each phase modulation element per step The optical signal selection device according to claim 12, comprising a plurality of steps in which the amount of change in phase modulation at 2 is 2π / (n−1) or less.   In the first pattern switching step or the second pattern switching step, each column along the switch direction of the phase modulation element is switched before switching in one period in the spectral direction of the periodic phase modulation. 16. The optical signal selection device according to claim 15, wherein phase modulation is started over time from the column in which the amount of change in phase modulation between the pattern and the pattern after switching is large.   The first pattern switching step or the second pattern switching step is performed for each column along the switch direction of the phase modulation element within one period in the spectral direction of the periodic phase modulation. 16. The optical signal selection device according to claim 15, wherein switching of phase modulation is started at the same time, and switching of phase modulation is finished in the order in which a predetermined phase is reached for each column.   The control device includes a storage unit that stores parameters used for control, and the control unit reads the parameters from the storage unit and controls the optical deflector. The optical signal selection device according to one.

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