JP2010079251A - Optical switch and method of controlling optical switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calculate an optimum driving voltage at a higher speed. <P>SOLUTION: On a plane having coordinate axes of operation amounts V<SB>x</SB>and V<SB>y</SB>, a perturbation pattern is set in which time-varying differences ΔV<SB>x</SB>and ΔV<SB>y</SB>have at least one value on each quadrant taking the original point as a starting point and a terminal point, respectively. New operation amounts V<SB>x</SB>and V<SB>y</SB>giving a tilt angle of a mirror at which the strongest light intensity is detected are calculated from the variation in the light intensity of output light detected with an output light measurement apparatus 4 when the mirrors of a micromirror apparatus 3a, 3b are perturbed according to the perturbation pattern, the operation amounts V<SB>x</SB>and V<SB>y</SB>, and the differences ΔV<SB>x</SB>and ΔV<SB>y</SB>. Thus, a method of driving is achieved in which influences of searching of the operation amounts in all directions on the plane and the residual vibration due to the dynamic characteristic of the mirror at a high speed driving are reduced. As a result, the driving voltage giving the maximum light intensity is calculated at a high speed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical switch.

  Conventionally, as a technique for realizing an optical switch, a technique using a micromirror has been proposed (see, for example, Non-Patent Document 1). An example of a conventional optical switch using a micromirror is shown in FIG.

  The optical switch shown in FIG. 10 includes an input port 1a, an output port 1b, an input side micromirror array 2a, and an output side micromirror array 2b. The input port 1a and the output port 1b are each composed of a plurality of optical fibers arranged two-dimensionally, and the micromirror arrays 2a and 2b are each composed of a plurality of micromirror devices 3a and 3b arranged two-dimensionally. . In addition, the arrow in FIG. 10 has shown the advancing direction of the light beam.

  An optical signal emitted from a certain input port 1a is reflected by the mirror of the micromirror device 3a of the input side micromirror array 2a corresponding to the input port 1a, and the traveling direction is changed (deflected). As will be described later, the mirror of the micromirror device 3a is configured to be rotatable about two axes, and the reflected light of the micromirror device 3a can be directed to any micromirror device 3b of the output side micromirror array 2b. it can. Similarly, the mirror of the micromirror device 3b is also configured to be rotatable about two axes, and the reflected light of the micromirror device 3b is directed to an arbitrary output port 1b by appropriately controlling the tilt angle of the mirror. be able to. Therefore, by appropriately controlling the tilt angles of the mirrors of the input side micromirror array 2a and the output side micromirror array 2b, the optical path is switched between the input and output ports, and any input port 1a arranged two-dimensionally. Can be connected to the output port 1b.

  The most characteristic components of such an optical switch are micromirror devices 3a and 3b having mirrors. Conventionally, as shown in FIGS. 11 and 12, the micromirror device has a structure in which a mirror substrate 200 on which a mirror is formed and an electrode substrate 300 on which an electrode is formed are arranged in parallel (non-patent document). Reference 1).

  The mirror substrate 200 includes a plate-shaped frame portion 210, a movable frame 220 disposed in the opening of the frame portion 210, and a mirror 230 disposed in the opening of the movable frame 220. The frame part 210, the torsion springs 211a, 211b, 221a, 221b, the movable frame 220 and the mirror 230 are integrally formed of, for example, single crystal silicon. For example, three Ti / Pt / Au layers are formed on the surface of the mirror 230. The pair of torsion springs 211 a and 211 b connect the frame part 210 and the movable frame 220. The movable frame 220 and the mirror 230 can rotate about the movable frame rotation axis X of FIG. 11 passing through the pair of torsion springs 211a and 211b. Similarly, the pair of torsion springs 221 a and 221 b couple the movable frame 220 and the mirror 230. The mirror 230 can rotate about the mirror rotation axis Y of FIG. 11 passing through the pair of torsion springs 221a and 221b. The movable frame rotation axis X and the mirror rotation axis Y are orthogonal to each other. As a result, the mirror 230 rotates about two orthogonal axes.

  The electrode substrate 300 has a plate-like base portion 310 and a terrace-like protruding portion 320. The base 310 and the protrusion 320 are made of, for example, single crystal silicon. The protrusion 320 includes a second terrace 322 having a truncated pyramid shape formed on the upper surface of the base 310, a first terrace 321 having a truncated pyramid shape formed on the upper surface of the second terrace 322, and the first terrace. And a pivot 330 having a columnar shape formed on the upper surface of 321. Four electrodes 340 a to 340 d are formed on the four corners of the protruding portion 320 and the upper surface of the base portion 310 following the four corners. In addition, a pair of convex portions 360 a and 360 b are provided on the upper surface of the base portion 310 so as to sandwich the protruding portion 320. Further, a wiring 370 is formed on the upper surface of the base 310, and electrodes 340a to 340d are connected to the wiring 370 via lead lines 341a to 341d. An insulating layer 311 made of silicon oxide or the like is formed on the surface of the base 310, and electrodes 340a to 340d, lead lines 341a to 341d, and wirings 370 are formed on the insulating layer 311.

  The mirror substrate 200 and the electrode substrate 300 as described above are formed by joining the lower surface of the frame portion 210 and the upper surfaces of the convex portions 360a and 360b so that the mirror 230 and the electrodes 340a to 340d are opposed to each other. A micromirror device as shown in FIG. 12 is configured. In such a micromirror device, the mirror 230 is grounded, a driving voltage is applied to the electrodes 340a to 340d, and an asymmetric potential difference is generated between each of the electrodes 340a to 340d and the mirror 230. Torque is applied by attractive force, and the mirror 230 can be tilted in an arbitrary direction.

T. Yamamoto, et al., `` A three-dimensional MEMS optical switching module having 100 input and 100 output ports '', Photonics Technology Letters, IEEE, Volume 15, Issue: 10

  In the optical switch as described above, it is required to control the tilt angle of the mirror so that light input from the input port is output from an arbitrary output port. However, the positional error between the I / O port and the mirror and the change in the tilt angle of the mirror occur due to environmental changes such as ambient temperature and humidity, and external vibration, and the deviation from the optimum mirror tilt angle gradually increases. There is a case where a drift occurs in which the power loss of output light increases with time. When the cause of loss fluctuation occurs in an optical switch used in a general optical network system, the entire optical network system is greatly affected. Therefore, the optical connection strength of the optical switch (the optical intensity of the output light relative to the input light) is reduced. It is necessary to keep it within a predetermined allowable value.

  However, if the amount of drift per unit time is large, the loss of optical connection strength may exceed the allowable value unless any measures are taken to suppress this drift. For this reason, in the optical switch, stabilization control is performed to stabilize the optical connection strength by monitoring the light intensity of the output light. Specifically, this stabilization control is performed by the following procedure. First, a control device (not shown) that controls the tilt angle of the mirror 230 supplies a drive voltage that periodically changes to the micromirror devices 3a and 3b, and perturbs (vibrates) the mirror 230 while outputting the output port. The light intensity of the output light is measured by an output light measuring device (not shown) provided on the output end side of 1b. Next, the drive voltage that obtains the maximum optical connection strength while holding the drive voltage that periodically changes and the value of the light intensity of the output light on the storage device of the control device and comparing the maximum value of the light intensity of the output light Is determined as the optimum drive voltage. For example, the optimum drive voltage is obtained by a so-called hill-climbing method in which the drive voltage is varied from the initial output voltage by a voltage width ± ΔV and the maximum value is searched while observing the light intensity of the output light at that time. Finally, the obtained optimum driving voltage is sequentially applied to the mirror. Optical connection strength is stabilized by repeating such stabilization control at regular time intervals.

  In such a so-called maximum value comparison type optimum value search, when the perturbation for the search for the maximum optical connection strength is performed, if it is affected by some noise or the like from the outside, the original maximum optical connection strength is If there is not, the maximum optical connection strength may be mistaken, and the wrong optimum drive voltage may be obtained. Such a phenomenon has been an unavoidable problem in the maximum value comparison type.

  In addition, when the conventional method is applied to a micromirror device, the maximum value comparison search with a simple three-point perturbation trajectory is performed by setting the movement time between points in order to avoid the influence of residual vibration during movement of each point due to the mirror dynamic characteristics. Since it is necessary to take enough, it was difficult to increase the speed. Furthermore, depending on the set perturbation trajectory, it is impossible to calculate the optimum drive voltage if the search direction is wrong. Therefore, it is necessary to add processing to avoid this, and this processing time Will become longer.

  Accordingly, an object of the present invention is to calculate an optimum drive voltage at a higher speed.

In order to solve the above-described problems, an optical switch according to the present invention includes at least one input port that inputs input light, at least one output port that outputs output light, and an X axis and a Y that are orthogonal to each other. At least one mirror device including a mirror rotatably supported with respect to the axis, and an electrode disposed opposite to the mirror, and an operation amount for rotating the mirror about the X axis and the Y axis, respectively. A control unit that deflects input light by applying a driving voltage according to V _x and V _y to the electrodes and tilting the mirror by a predetermined amount to selectively enter the output port. varies, of perturbation a setting unit that sets a perturbation pattern consisting of variation [Delta] V _x and [Delta] V _y with respect to the operation amount V _x and V _y, mirrors to modulate the manipulated variable V _x and V _y in perturbation pattern Perturbation unit, a detection unit for detecting the light intensity of the output light incident on the output port by the mirror, and fluctuations in the light intensity of the output light detected by the detection unit when the mirror is perturbed according to the perturbation pattern And an operation processing unit for calculating new operation amounts V _x and V _y that give the tilt angle of the mirror in which the strongest light intensity is detected from the operation amounts V _x and V _y and the changes ΔV _x and ΔV _y. The setting unit is a perturbation pattern in which changes ΔV _x and ΔV _y that change with time on the plane having the operation amounts V _x and V _y as coordinate axes take at least one value in each quadrant with the origin as the start point and the end point. Is set.

In the optical switch, the perturbation pattern may draw two circles circumscribed at the origin on the plane with the changes ΔV _x and ΔV _y that change with time according to a trigonometric function.

  In the above optical switch, the control unit stores a storage unit that stores an allowable value of the loss change amount of the output light, and fluctuations in the light intensity of the output light detected by the detection unit when the mirror is perturbed according to the perturbation pattern. And a setting unit that reduces the radius of the circle of the perturbation pattern used for the next perturbation when the fluctuation width is larger than the allowable value, and the next time when the fluctuation width is smaller than the allowable value. You may make it enlarge the radius of the circle of the perturbation pattern used for perturbation.

In the optical switch, the new manipulated variables V _x and V _y may take values on the perturbation pattern. At this time, the setting unit may start from the new operation amounts V _x and V _y .

  In the above optical switch, the mirror device includes a first mirror device and a second mirror device, and the first mirror device deflects the input light input to the input port to provide the second mirror device. The second mirror device may deflect the light incident from the first mirror device so that the light is selectively incident on an arbitrary output port.

Also, the optical switch control method according to the present invention is configured to rotate at least one input port for inputting input light, at least one output port for outputting output light, and an X axis and a Y axis orthogonal to each other. According to a mirror that is movably supported, at least one mirror device having an electrode disposed opposite to the mirror, and operation amounts V _x and V _y that rotate the mirror about the X axis and the Y axis, respectively. And a control unit for deflecting input light by selectively applying the drive voltage to the electrode and tilting the mirror by a predetermined amount so as to selectively enter the output port. , feeding a setting step of setting a perturbation pattern consisting of variation [Delta] V _x and [Delta] V _y with respect to the operation amount V _x and V _y, mirrors to modulate the manipulated variable V _x and V _y in perturbation pattern Perturbation step, detection step for detecting the light intensity of the output light incident on the output port by the mirror, and fluctuation of the light intensity of the output light detected by the detection step when the mirror is perturbed according to the perturbation pattern And a calculation processing step for calculating new operation amounts V _x and V _y that give a tilt angle of the mirror in which the strongest light intensity is detected from the operation amounts V _x and V _y and the changes ΔV _x and ΔV _y. The setting step is a perturbation in which changes ΔV _x and ΔV _y that vary with time on the plane having the operation amounts V _x and V _y as coordinate axes take at least one value in each quadrant with the origin as the starting point and the ending point. It is characterized by setting a pattern.

In another optical switch control method according to the present invention, at least one input port for inputting input light, at least one output port for outputting output light, an X axis, and a Y axis orthogonal to the X axis The mirror is supported so as to be rotatable with respect to the mirror, and an electrode disposed opposite to the mirror. The drive voltage corresponding to the operation amount is applied to the electrode, and the mirror is tilted to be input to the input port. The first mirror device and the second mirror device that deflect the input light and selectively enter the arbitrary output port, and the mirrors of the first mirror device and the second mirror device are rotated around the X axis and the Y axis. A control unit that deflects input light and selectively enters an output port by applying a driving voltage corresponding to the operation amounts V _x and V _y to rotate around the electrode and tilting the mirror by a predetermined amount; A first step of setting a perturbation pattern consisting of changes ΔV _x and ΔV _{y with} respect to the manipulated variables V _x and V _y , which varies with time, and is operated with the perturbation pattern The second step of perturbing the mirror of the first mirror device by modulating the quantities V _x and V _y and the input light from one input port is 1 when the mirror of the first mirror device is perturbed. A third step of detecting the light intensity of the output light output from the output port of the first output device, and output light detected by the third step when the mirror of the first mirror device is perturbed according to the perturbation pattern New operation amounts V _x and V _y that give the tilt angle of the mirror in which the strongest light intensity is detected are calculated from the fluctuation of the light intensity and the operation amounts V _x and V _y and the changes ΔV _x and ΔV _y , Mi of the first mirror device A fourth step of correcting the tilting angle of over a fifth step of perturbing the mirror of the second mirror device by modulating the operation amount V _x and V _y in perturbation pattern, a mirror of the second mirror device A sixth step of detecting the light intensity of the output light output from the one output port when the input light from the one input port is perturbed, and the mirror of the second mirror device according to the perturbation pattern Of the mirror in which the strongest light intensity is detected from the fluctuations in the light intensity of the output light detected by the fifth step, the manipulated variables V _x and V _y, and the changes ΔV _x and ΔV _y . And calculating a new manipulated variable V _x and V _y that gives a tilt angle, and correcting a tilt angle of the mirror of the second mirror device. The first step includes the manipulated variable V _x and On the plane with V _y as the coordinate axis, A change pattern ΔV _x and ΔV _y that fluctuate intermittently is set as a starting point and an ending point, a perturbation pattern having at least one value is set in each quadrant, and the second to seventh steps are repeated.

In the optical switch control method, the fifth step is a state in which the drive voltage corresponding to the new operation amounts V _x and V _y calculated in the fourth step is applied to the electrodes of the first mirror device. Above, the mirror of the second mirror device is perturbed. In the second step, the drive voltage corresponding to the new operation amounts V _x and V _y calculated in the seventh step is applied to the electrode of the second mirror device. The mirror of the first mirror device may be perturbed after being applied to.

According to the present invention, on the plane with the manipulated variables V _x and V _y as coordinate axes, perturbations in which changes ΔV _x and ΔV _y that vary with time take at least one value in each quadrant with the origin as the start point and the end point. The pattern is set, and when the mirror is perturbed according to the perturbation pattern, the light intensity variation of the output light detected by the detector, the manipulated variables V _x and V _y, and the changes ΔV _x and ΔV _y are the most. By calculating new operation amounts V _x and V _y that give the tilt angle of the mirror in which strong light intensity is detected, the omnidirectional search on the plane of the operation amount and high-speed driving by the dynamic characteristics of the mirror A driving method in which the influence of residual vibration is reduced can be realized, and as a result, a driving voltage that maximizes the light intensity can be calculated at high speed.

  In addition, according to the present invention, by setting a perturbation pattern that draws an 8-shaped trajectory, even when there is a value deviating from a value that should originally be obtained due to the influence of disturbance noise at a certain timing, Since the averaging process using the intensity is realized, it is possible to calculate the drive voltage that maximizes the light intensity. For this reason, robustness against disturbance noise can be improved.

  Furthermore, according to the present invention, by providing a fluctuation range calculation unit for calculating the fluctuation range of the output light intensity, when the light intensity fluctuation range is larger than the allowable value, the radius of the circular locus of the perturbation pattern used for the next perturbation is set. If the fluctuation width is smaller and smaller than the allowable value, the radius of the circular locus of the perturbation pattern used for the next perturbation is increased, and the perturbation radius is increased or decreased based on the calculated fluctuation width. Stabilization of the output light intensity can be realized.

It is a block diagram which shows the structure of the optical switch which concerns on this invention. It is a block diagram which shows the structure of a control apparatus. It is a figure for demonstrating a perturbation pattern. It is a flowchart which shows operation | movement of the optical switch which concerns on this invention. It is a figure which shows an example of the amount of perturbation operation supplied to the micromirror device 3a. It is a figure which shows an example of the amount of perturbation operation supplied to the micromirror device 3b. It is a figure which shows the experimental result of this invention. It is a flowchart which shows optimal value movement operation | movement. It is a figure which shows the structure of a wavelength selective switch typically. It is a perspective view which shows the structure of an optical switch typically. It is a perspective view which shows the structure of a mirror apparatus typically. It is sectional drawing which shows the structure of a mirror apparatus typically.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
First, a first embodiment according to the present invention will be described. In the present embodiment, the same components as those described in the background art section with reference to FIG. 10, FIG. 11, and FIG.

<Configuration of optical switch>
As shown in FIG. 1, the optical switch 10 according to the present embodiment includes an input port 1a, an output port 1b, an input side micromirror device 3a, an output side micromirror device 3b, and an output light measurement device 4. And a control device 5.

  The output light measuring device 4 detects the intensity of the output light emitted from the output port 1b and converts it into an electrical signal. As a configuration example of such an output light measuring device 4, a part of the output light may be cut out by a half mirror or the like, and the intensity of the output light may be measured by a light receiving element such as a photodiode.

  The control device 5 includes a drive unit 6 that applies a drive voltage to the micromirror devices 3 a and 3 b, a detection unit 7 that detects the intensity of the output light measured by the output light measurement unit 8, and the drive unit 6 and the detection unit 7. And a storage unit 9 for storing various types of information used for control by the control unit 8.

  The drive unit 6 generates a drive voltage to be applied to the electrodes of the micromirror devices 3a and 3b based on the operation amount input from the control unit 8, and applies this to the corresponding electrode to tilt the mirror 230.

  The detection unit 7 detects the measurement result of the output light by the output light measurement device 4 when the driving unit 6 drives the micromirror devices 3a and 3b. The detected measurement result is output to the control unit 8.

  The control unit 8 is a functional unit that controls the operation of the entire optical switch. As illustrated in FIG. 2, the switching unit 81, the perturbation pattern setting unit 82, the comparison update unit 83, and the operation amount generation unit 84 And at least an error calculation correction unit 85.

When the switching unit 81 establishes an optical path between an arbitrary input port 1a and an arbitrary output port 1b, an operation amount corresponding to the tilt angle of the micromirror device 3a corresponding to these ports and the mirror 230 of the micromirror device 3b. Is read from the storage unit 9 and input to the drive unit 6. Then, the drive unit 6 applies a voltage to the four electrodes 340a to 340d arranged to face the mirror 230 illustrated in FIG. 11 based on the operation amount input from the switching unit 81. Thereby, the mirror 230 rotates around the X axis and the Y axis and tilts in an arbitrary direction. Here, the tilt angle about the X axis of the mirror 230 is θ _x , the tilt angle about the Y axis is θ _y , and the operation amounts corresponding to the tilt angles θ _x and θ _y are respectively V _x and V _y . Then, applied voltages V1 to V4 to the electrodes 340a to 340d are expressed by the following expressions (101) to (104). As shown in FIG. 11, the electrodes 340a to 340d are arranged in a plane horizontal to the X axis and the Y axis, the electrode 340a being the first and second quadrants, the electrode 340b being the second and third quadrants, and the electrode 340c. Are arranged in the third and fourth quadrants, the electrode 340d is arranged in the fourth and first quadrants, the electrodes 340a and 340c are arranged in line symmetry with respect to the X axis, and the electrodes 340b and 340d are arranged in line symmetry with respect to the Y axis. ing. Therefore, the tilt angle θ _x of the mirror 230 around the X axis is driven by the electrodes 340a and 340c, and the tilt angle θ _y of the mirror 230 around the Y axis is driven by the electrodes 340b and 340d. At this time, the direction in which the mirror 230 approaches the electrode 340a is the positive direction around the X axis, and the direction in which the mirror 230 approaches the electrode 340b is the positive direction around the Y axis.

V ₁ = V ₀ + V _x (101)
V ₂ = V ₀ + V _y (102)
V ₃ = V ₀ −V _x (103)
V ₄ = V ₀ −V _y (104)

In the above formulas (101) to (104), V ₀ is called a bias voltage and can improve the linearity from the operation amount to the mirror tilt angle.

The perturbation pattern setting unit 82 sets a perturbation pattern composed of changes ΔV _x and ΔV _{y with} respect to the manipulated variables V _x and V _y that vary with time. In this perturbation pattern, changes ΔV _x and ΔV _y that vary with time on a plane having the manipulated variables V _x and V _y as coordinate axes have a starting point and an ending point, and take at least one value in each quadrant. For example, as shown in FIG. 3, in the perturbation pattern, changes ΔV _x and ΔV _y that temporally vary according to a trigonometric function are circumscribed at the origin on a plane having the manipulated variables V _x and V _y as coordinate axes. Draw an eight-shaped locus consisting of two circles. Such perturbation patterns, a parameter Vs for determining the radius of the two circles, the variation [Delta] V _x and [Delta] V variation [Delta] V by connecting the respective perturbation points consisting of _y draw-shaped trajectory of 8 _x and [Delta] V _y Is set based on the quantity Pt (hereinafter referred to as the number of perturbation points). In this embodiment, the case where the perturbation pattern draws a figure-shaped trajectory will be described as an example. However, the changes ΔV _x and ΔV _y have an origin as an origin and an end point, and each quadrant has a value of at least 1. If it is to be taken, for example, a character shape of ∞ can be set freely.

Here, in order to perturb the mirror 230 with an 8-shaped trajectory, an operation amount that is periodically changed to the micromirror devices 3a and 3b, that is, (V _x + ΔV _x , V _y + ΔV _y ) is expressed as “perturbation operation amount”. " Further, “perturbation” means that the mirror 230 is rotationally perturbed from the initial tilt angle by applying a drive voltage generated based on the perturbation operation amount to each electrode of the micromirror devices 3a and 3b. . As described above, when the four electrodes 340a to 340d are provided as shown in FIGS. 11 and 12, the mirror 230 is perturbed by applying the drive voltage generated based on the perturbation operation amount to each electrode. However, the drive voltage to each electrode is determined according to the positional relationship with the mirror 230 and the direction in which the mirror 230 is perturbed. For example, when the perturbation operation amount in the X-axis direction is set to Vx = 10 [V] and the perturbation operation amount Vy in the Y-axis direction is set to −20 [V], 10 [V] is applied to the electrode 340a and 20 [V is set to the electrode 340d. V] is applied. For example, when the linearity from the perturbation operation amount to the tilt angle is increased using the bias voltage, the drive voltage is converted from the perturbation operation amount according to the equations (101) to (104). Assuming that the bias voltage V ₀ = 30 [V], V ₀ + V _x = 40 [V] is applied to the electrode 340a, V ₀ + V _y = 10 [V] is applied to the electrode 340b, and V ₀ −V _x = 20 [V] is applied to the electrode 340c. ], A voltage of V ₀ −V _y = 50 [V] is applied to the electrode 340d. Conversion from these perturbation operation amounts into drive voltages is performed by the drive unit 6. Hereinafter, a voltage applied to rotate the mirror 230 in the X-axis direction is referred to as an X-axis direction operation amount, and a voltage applied to rotate the mirror 230 in the Y-axis direction is referred to as a Y-axis direction operation amount. The parameter Vs and the number of drive points pt set by the perturbation pattern setting unit 82 are stored in the storage unit 9.

  The comparison update unit 83 uses a loss fluctuation range estimated value ΔPp, which will be described later, calculated by the error calculation correction unit 85 and a loss change amount allowable value ΔP stored in advance in the storage unit 9 to be used for the next perturbation. The parameter Vs is calculated. Further, the parameter Vs set by the perturbation pattern setting unit 82 is updated based on the calculation result. The updated parameter Vs is output to the perturbation pattern setting unit 82.

  When connecting the optical path between any input port 1a and any output port 1b, the manipulated variable generation unit 84 applies to the micromirror device 3a and the mirror 230 of any micromirror device 3b corresponding to each port. Thus, an operation amount (perturbation operation amount) is generated based on the perturbation pattern set by the perturbation pattern setting unit 82. This operation amount is input to the drive unit 6.

  The error calculation correction unit 85 determines the optical path when the light intensity of the output light is maximum from the detection result of the light intensity of the output light by the detection unit 7 when the mirror 230 is perturbed by the operation amount generation unit 84. An operation amount that realizes the tilt angle of the mirror 230 of the micromirror devices 3a and 3b corresponding to the connected input port 1a and output port 1b (hereinafter referred to as “optimum operation amount”) is calculated. Further, an estimated value ΔPp of the loss fluctuation range when the mirror 230 is perturbed by an 8-shaped locus is calculated. The calculated optimum operation amount and loss fluctuation range estimated value ΔPp are stored in the storage unit 9. The estimated loss fluctuation range ΔPp may be input to the comparison / update unit 83.

  The storage unit 9 includes a parameter Vs set by the perturbation pattern setting unit 82, the number of drive points pt, a preset loss variation allowable value ΔP, a perturbation pattern set by the operation amount generation unit 84, an optimum operation amount, and an optical switch. A program or the like for realizing 10 operations is stored.

  Such a control device 5 includes an arithmetic device such as a CPU, a storage device such as a memory and an HDD (Hard Disk Drive), an input device that detects information input from the outside such as a keyboard, a mouse, a pointing device, a button, and a touch panel, I / F devices and CRT (Cathode Ray Tube), LCD (Liquid Crystal Display), FED (Field) which send and receive various information via communication lines such as the Internet, LAN (Local Area Network), WAN (Wide Area Network) It is comprised from the computer provided with display apparatuses, such as Emission Display) and organic EL (Electro Luminescence), and the program installed in this computer. That is, the hardware resource and the software cooperate to control the hardware resource by a program, thereby realizing the drive unit 6, the detection unit 7, the control unit 8, and the storage unit 9 described above. The program may be provided in a state where it is recorded on a recording medium such as a flexible disk, a CD-ROM, a DVD-ROM, or a memory card.

<Operation of control device>
Next, the operation of the optical switch control device according to the present embodiment will be described with reference to FIG.

  First, the switching unit 81 of the control unit 8 stores an initial operation amount corresponding to the initial tilt angle of the mirror 230 of the micromirror devices 3a and 3b corresponding to each of the input port 1a and the output port 1b connecting the optical paths. Read from the unit 9 and input to the drive unit 6. The drive unit 6 applies a drive voltage based on the input initial operation amount to the corresponding electrodes of the respective micromirror devices 3a and 3b (step S0).

  Next, the operation amount generation unit 84 of the control unit 8 generates an operation amount (perturbation operation amount) based on the perturbation pattern set by the perturbation pattern setting unit 82, and inputs this to the drive unit 6. A drive voltage is applied to the corresponding electrodes of the micromirror devices 3a and 3b, and the mirror 230 is perturbed from the initial tilt angle (step S1). The details of the perturbation pattern setting operation will be described later.

  With the mirror 230 being perturbed, the detection unit 7 detects the light intensity of the output light from the output port 1b measured by the output light measurement device 4 (step S2). The detected light intensity is input to the error calculation correction unit 85.

  When the light intensity at the time of perturbation is detected, the error calculation correction unit 85 of the control unit 8 operates the operation amount for obtaining the maximum value of the light intensity from the perturbation operation amount and the light intensity value at each perturbation operation amount, that is, the optimum operation amount. Thus, the initial operation amount described above is corrected and updated, and the tilt angle of the mirror 230 is adjusted (step 3). Details of the optimum value search operation by the error calculation correction unit 85 will be described later. At this time, the error calculation correction unit 85 calculates the estimated loss fluctuation range ΔPp when the mirror 230 is perturbed with an 8-shaped locus.

  When the optimum operation amount is calculated, the comparison / update unit 83 compares the loss fluctuation range estimated value ΔPp calculated by the error calculation correction unit 85 with the loss variation allowable value ΔP stored in the storage unit 9. When the mirror 230 is perturbed along the 8-shaped trajectory, the parameter Vs indicating the radius of the two circles constituting the 8-shaped trajectory is updated (step S4). Details of such a parameter update operation will be described later.

  When processing other than steps S0 to S4 described above is requested (step S5: YES), the control device 5 performs other processing (step S6). On the other hand, when processing other than the above-described steps S0 to S4 is not required (step S5: NO), the control device 5 returns to the processing of step S1 and repeats the processing for stably performing the optical switch as described above. It performs (step S6).

<Perturbation pattern setting operation>
Next, details of the perturbation pattern setting operation by the perturbation pattern setting unit 82 of the control unit 8 will be described. The perturbation operation amount pattern setting operation is an operation for setting a perturbation pattern used to generate a perturbation operation amount to be supplied to the micromirror devices 3a and 3b in order to perturb the mirror 230. This operation will be described by taking as an example the case of setting a perturbation operation amount for drawing an 8-shaped locus supplied to an arbitrary micromirror device 3a.

When the perturbation pattern setting unit 82 sets eight perturbation operation amounts of an arbitrary micromirror device 3a, the initial value _Vx0 of the operation amount in the X-axis direction of the micromirror device 3a and the initial operation amount in the Y-axis direction Based on the value V _yo , the parameter Vs indicating the radius of the two circles constituting the 8-shaped locus and the number of drive points Pt, the perturbation operation amount (V _{x at} each drive point i is calculated from the following equations (1) to (3). + ΔV _x , V _y + ΔV _y ) is calculated. The initial values _Vxo , _Vyo , the parameter Vs, and the drive point number Pt are stored in advance in the storage unit 9. Further, it is assumed that the X axis and the Y axis are set to be substantially parallel to the mirror 230 and orthogonal to each other. Moreover, i in the following formulas (1) to (3) means an identification number of a driving point.

V _x [i] = V _xo + V _s * sin (i * 4π / Pt) (1)
V _y [i] = V _yo -V _s * cos (i * 4π / Pt) + V _s (i = 1,2,…, Pt / 2) (2)
V _y [i] = V _yo + V _s * cos (i * 4π / Pt) −V _s (i = Pt / 2 + 1,…, Pt) (3)

  5 and 6 show examples of the operation amount calculated by setting the number of driving points to 20 according to the above formulas (1) to (3). In the case of the micromirror device 3a, perturbation operation amounts arranged in an 8-shape as shown in FIG. 5 are set. Similarly, in the case of the micromirror device 3b, perturbation operation amounts arranged in an 8-shaped locus as shown in FIG. 6 are set. Such a series of perturbation manipulated variables is called a perturbation pattern. In addition, each point of the perturbation operation amount shown in FIGS. 5 and 6 indicates the operation amount in the X direction and the Y direction.

  The perturbation pattern set as described above is used by the operation amount generation unit 84 as described below.

In a state where an optical signal is input from the outside to the input port 1a and an optical path is connected to the output port 1b, the manipulated variable generation unit 84 transmits light for the micromirror device 3a and the micromirror device 3b corresponding to each port. In order to search for an optimum operation amount with a small signal connection loss, the mirror 230 is perturbed with a preset perturbation pattern. First, initial values Vx ₀₂ and Vy ₀₂ of the operation amount of the micromirror device 3b are set, and the 20 perturbation operation amounts constituting the perturbation pattern with respect to the micromirror device 3a are converted into drive voltages by the drive unit 6. The mirror 230 is perturbed while sequentially outputting. At this time, the light intensity of the optical signal measured by the output light measurement device 4 via the detection unit 7 is stored in the storage unit 9.

When perturbing the mirror 230 based on perturbation pattern set in the micromirror device 3a, after returning the operation amount of the micromirror device 3a to the initial value Vx _01, Vy _01, as in the case of the micro-mirror device 3a Micro Perturbation of the mirror device 3b is performed. At this time, the light intensity of the optical signal measured by the output light measurement device 4 via the detection unit 7 is stored in the storage unit 9. At the stage where the perturbation of the micromirror device 3b has been completed, it returns the operation amount of the micromirror device 3b to the initial value Vx _02, Vy _02.

<Optimum value search operation>
Next, the optimum value search operation by the error calculation correction unit 85 will be described. With respect to the perturbation operation amounts substantially parallel to the mirror 230 and orthogonal to each other in the X-axis direction and the Y-axis direction, the sine function is used according to the above equation (1) for the X-axis direction, and the above equation ( Calculation is performed using a cosine function according to 2) and (3). The perturbation manipulated variable calculated in this way becomes a figure 8 locus as shown in FIGS. 5 and 6 on the V _x and V _y planes. In this way, when perturbed by an 8-shaped locus, the light intensity of the output light detected when the drive voltage corresponding to each perturbation operation amount in the perturbation pattern is applied is stored in the storage unit 9.

  Assuming that the obtained time series data of the light intensity P of the output light can be approximated to the cosine function shown in the following equation (4), the c-axis function and the X-axis and Y-axis perturbations in the case of the 8-shaped trajectory perturbation The phase difference θ with the sine or cosine function used for pattern setting is calculated. This calculation is performed by, for example, the least square method, the FFT calculation of the light intensity P, or the average of the product-sum calculation of the light intensity P and the perturbation operation amount. In the following formula (4), ΔPp represents the fluctuation range of the light intensity when perturbed by an 8-shaped locus.

P = P0 + ΔPp · cos (i * 4π / Pt-θ) (4)

  The phase difference calculated by the above equation (4) is defined as a direction angle θ for obtaining the maximum value of the light intensity P. A voltage value at a point defined as a function of the direction angle θ and the parameter Vs of the circular portion of the figure 8 locus is calculated and set as a drive voltage for one output port.

In addition, the following formulas (5) and (6) show a case where the maximum value direction angle is obtained for the micromirror device 3a, and the operation amount on the circle constituting the 8-shaped locus is obtained. Here, V _xp and V _yp are values of manipulated variables in the X-axis and Y-axis directions for obtaining the maximum value of the light intensity of the output light on a circle that forms an 8-shaped locus, respectively.

Vxp1 = Vx1o + Vs * sin (θ) (5)
Vyp1 = Vy1o-Vs * cos (θ) (6)

<Parameter update operation>
Next, the parameter update operation will be described. The comparison / update unit 83 compares the estimated loss fluctuation range ΔPp at the time of perturbation of the figure 8 trajectory calculated by the error calculation correction unit 85 with the allowable loss change amount ΔP stored in the storage unit 9, and A parameter Vs used for the perturbation of the U-shaped locus is set.

  Specifically, the following parameters are calculated based on the following equation (7) from the estimated loss fluctuation range ΔPp calculated from the light intensity data of the output light at the time of the 8-shaped locus perturbation and ΔP stored in the storage unit 9 in advance. Vs ′ is calculated. Here, when the output light intensity fluctuation width ΔPp is larger than the loss variation allowable value ΔP, the radius of the circular locus portion used for the next perturbation is reduced, and the output light intensity fluctuation width ΔPp becomes the loss variation allowable value ΔP. If it is smaller, the parameter Vs is updated so as to increase the radius of the circular locus portion used for the next perturbation. In the following equation (7), k is a parameter that determines the change width per perturbation of the radius voltage. is there.

Vs ′ = Vs + (ΔP−ΔPp) · k (7)

  In this way, the comparison update unit 83 updates the parameter Vs set by the perturbation pattern setting unit 82. The updated parameter Vs is output to the perturbation pattern setting unit 82 and used for setting the next circular locus perturbation.

  FIG. 7 shows a result of an experiment in which optical connection is performed using this embodiment and the stabilization control of the optical connection strength is performed. As shown in FIG. 7, the operation amount for obtaining the maximum value of the light intensity can be calculated, and it was confirmed that the optical connection strength can be maintained within the set loss change allowable value.

  At this time, the parameter Vs is set, and the operation amount corresponding to the driving voltage at the point defined as a function of the direction angle θ calculated by the above equation (4) and the parameter Vs is stored as an initial operation amount. It may be reset to 9. The drive voltage corresponds to any perturbation operation amount when the direction angle θ is calculated, that is, a value on the perturbation pattern. The reset initial manipulated variable becomes the starting point of the perturbation pattern used for the next perturbation.

As described above, according to the present embodiment, on the plane having the operation amounts V _x and V _y as coordinate axes, the temporally varying changes ΔV _x and ΔV _y have the origin as the starting point and the end point as the respective quadrants. Is set to a perturbation pattern having a value of at least 1, and when the mirror 230 is perturbed in accordance with this perturbation pattern, the variation in the light intensity of the output light detected by the detector 7 and the manipulated variables V _x and V _y, By calculating new operation amounts V _x and V _y that give the tilt angle of the mirror in which the strongest light intensity is detected from the changes ΔV _x and ΔV _y , search for all directions on the operation amount plane, and Thus, it is possible to realize a driving method in which the influence of the residual vibration at the time of high-speed driving due to the dynamic characteristics of the mirror is reduced, and as a result, it is possible to calculate the driving voltage at which the light intensity becomes maximum at high speed.

  Further, according to the present embodiment, even when there is a value deviating from a value that should be originally obtained due to the influence of disturbance noise at a certain timing, the averaging process using other acquired light intensities is realized. It is possible to calculate a driving voltage that maximizes the intensity. For this reason, robustness against disturbance noise can be improved.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described. The present embodiment is characterized by an operation for calculating an optimum operation amount based on a perturbation pattern. Therefore, in the present embodiment, the same components as those in the first embodiment described above are denoted by the same names and reference numerals, and the description thereof is omitted as appropriate.

<Perturbation pattern setting operation>
A perturbation pattern setting operation by the perturbation pattern setting unit 82 of the control unit 8 will be described. This perturbation pattern setting operation is an operation of setting a perturbation pattern used to perturb the mirror 230 of the micromirror devices 3a and 3b. With respect to this operation, the perturbation pattern has temporally varying changes ΔV _x and ΔV _y on the plane having the manipulated variables V _x and V _y as coordinate axes, with the origin as the start point and the end point, and at least one value in each quadrant An example in which the figure is set to draw an 8-shaped locus will be described.

When the perturbation pattern setting unit 82 sets a perturbation pattern for drawing an 8-shaped locus, the initial value Vx ₀ of the operation amount in the X-axis direction and the initial value of the operation amount in the Y-axis direction of the micromirror devices 3a and 3b. Vy ₀ , a parameter Vs for determining the radius of two circles constituting the 8-shaped trajectory and the number of perturbation points Pt are set. Based on these values, each driving point i is obtained from the above equations (1) to (3). The perturbation manipulated variable (V _x + ΔV _x , V _y + ΔV _y ) is calculated. Here, the initial values Vx _o and Vy _o , the parameter Vs, and the drive point number Pt are stored in the storage unit 9 in advance. Further, i in the above formulas (1) to (3) means an identification number of the driving point.
As shown in the first embodiment, when the perturbation is performed again after the optimum operation amount is calculated by the error calculation correction unit 85, the perturbation pattern setting unit 82 sets the optimum operation amount to the initial value Vx. _o, to set the perturbation pattern as Vy _o.

<Optimum value movement operation>
A series of operations (hereinafter referred to as “optimum value movement operation”) by the operation amount generation unit 84 using the perturbation pattern set as described above will be described with reference to FIG. The optimum value moving operation shown in FIG. 8 corresponds to steps S1 to S3 in the control operation of the optical switch described with reference to FIG. 4 in the first embodiment described above.

In a state where an optical signal is input from the outside to the input port 1a and an optical path is connected to the output port 1b, the manipulated variable generation unit 84 for the pair of micromirror devices 3a and micromirror devices 3b corresponding to each port. Oscillates the mirror 230 with the perturbation pattern set by the perturbation pattern setting unit 82 in order to search for an optimal operation operation amount with a small connection loss of the propagating optical signal. First, initial values Vx ₀₂ and Vy ₀₂ of the operation amount of the micromirror device 3b are set, and the 20 perturbation operation amounts are converted into drive voltages by the drive unit 6 according to the perturbation pattern set in the micromirror device 3a. The mirror 230 of the micromirror device 3a is perturbed while sequentially outputting to each electrode (step S11). At this time, the light intensity of the optical signal measured by the output light measurement device 4 via the detection unit 7 is stored in the storage unit 9 (step S12).

Mirror 230 is perturbed based on perturbation pattern set in the micromirror device 3a, this perturbation is completed, the operation amount of the micromirror device 3a returns to the initial value Vx _01, Vy _01. Then, the error calculation correction unit 85 outputs the optimum value search operation described in the first embodiment based on the light intensity of the optical signal when the micromirror device 3a stored in the storage unit 9 is perturbed. The optimum operation amount in the X-axis and Y-axis directions where the light intensity of light is maximized is calculated (step S13), and a drive voltage corresponding to this optimum operation amount is applied to the micromirror device 3a (step S14). Thereby, the tilt angle of the mirror 230 of the micromirror device 3a is set to an angle at which the light intensity of the output light is maximized.

  When a driving voltage corresponding to the optimum operation amount is applied to the micromirror device 3a, the operation amount generation unit 84 uses the perturbation pattern set by the perturbation pattern setting unit 82 as in the case of the micromirror device 3a. The mirror 230 of 3b is perturbed (step S15). At this time, the light intensity of the optical signal measured by the output light measurement device 4 via the detection unit 7 is stored in the storage unit 9 (step S16).

Mirror 230 is perturbed based on perturbation pattern set in the micromirror device 3b, this perturbation is completed, the operation amount of the micromirror device 3b returns to the initial value Vx _02, Vy _02. Then, as in the case of the micromirror device 3a, the error calculation correction unit 85 determines the light intensity of the output light based on the light intensity of the optical signal when the micromirror device 3b stored in the storage unit 9 is perturbed. The optimum operation amounts in the X-axis and Y-axis directions that are maximum are calculated (step S17), and a drive voltage corresponding to the optimum operation amount is applied to the micromirror device 3b (step S18). Thereby, also about the mirror 230 of the micromirror device 3b, the tilt angle is set to an angle at which the light intensity of the output light is maximized.

  When such steps S11 to S18 are performed, the parameter update operation shown in step S4 of FIG. 4 is performed. At this time, the parameter Vs is set, and the operation amount corresponding to the drive voltage at the point defined as a function of the direction angle θ calculated by the above equation (4) and the parameter Vs, that is, the drive corresponding to the optimum operation amount. The voltage is set in the storage unit 9 as an initial operation amount. The reset initial manipulated variable becomes the starting point of the perturbation pattern used for the next perturbation.

  After the parameter update operation of step S4 is performed, when processing other than steps S0 to S4 is not requested (step S5: NO), the control device 5 returns to the processing of step S1 and performs the processing of steps S11 to S18 described above. Is done again. At this time, the perturbation pattern used for perturbation of the micromirror devices 3a and 3b is set with the drive voltage corresponding to the optimum operation amount calculated by the previous perturbation as a starting point. In step S11, the mirror 230 of the micromirror device 3a is perturbed with the drive voltage corresponding to the optimum operation amount calculated in step S18 executed immediately before being applied to the micromirror device 3b. It becomes.

  As described above, according to the present embodiment, when calculating the optimum operation amount of the micromirror device 3a, the optimum operation amount of the micromirror device 3b is calculated and the drive voltage corresponding to the optimum operation amount is set to the micromirror. Similarly, when the optimum operation amount of the micromirror device 3b is calculated, the optimum operation amount of the micromirror device 3a is calculated and the drive voltage corresponding to the optimum operation amount is set to the micromirror. It is set as the state applied to the apparatus 3a. As a result, the mutual influence of the error from the optimum operation amount of the micromirror devices 3a and 3b on the optimum value search can be minimized, so that the amount of movement to the optimum value is reduced and the light intensity is maximized. Can be calculated at high speed. In addition, the accuracy of the optimum value search itself can be improved.

  Further, by matching the starting point and the end point of perturbation for each of the micromirror devices 3a and 3b, it is possible to reduce the influence of residual vibration during high-speed driving due to the mirror dynamic characteristics at the end point. In addition, when the vicinity of the starting point is the optimal operation amount, the amount of movement from the starting point to the optimal operation amount is small, so that the influence of residual vibration during high-speed driving due to the mirror dynamics can be reduced and the residual amount Since it is not necessary to wait for a long time until the vibration is attenuated, the optimum value search can be speeded up.

  Further, the perturbation components ΔVx and ΔVy are set to the initial value of the operation amount by taking at least one value in each quadrant with the origin as the perturbation start and end points on the plane having the operation amounts Vx and Vy as the coordinate axes. On the other hand, the optimum value search can be performed regardless of the optimum value in any direction.

  In simple circular trajectory perturbation, if the starting point and end point of the perturbation trajectory are matched so as to reduce the amount of movement to the optimal point, and an omnidirectional search is attempted, a circular trajectory centered on the optimal point is used. It is necessary to. For this reason, the optimal point cannot be set on the perturbation trajectory, and when performing the next perturbation, it is necessary to always start from a position shifted by the radial voltage. The effect of residual vibration during driving was inevitable. On the other hand, according to the present embodiment, since the figure-shaped trajectory in which the search direction takes at least one value in each quadrant is set as the perturbation manipulated variable, the omnidirectional setting the optimum point on the perturbation trajectory Search is possible.

  Also in the present embodiment, the operation similar to that in the first embodiment described above can be applied to the optimum value search operation. That is, as in the first embodiment, by performing the optimum value search operation, it is possible to reduce the influence of noise as compared with the conventional maximum value comparison method. As a result, even if there is a value deviating from the value originally obtained due to the influence of disturbance noise at a certain timing, the averaging process using other acquired light intensity can be realized, so that the drive voltage that maximizes the light intensity can be obtained. Can be calculated. For this reason, robustness against disturbance noise can be improved.

  Further, regarding the parameter update operation, the same operation as that of the first embodiment can be applied. That is, as in the first embodiment, by adjusting the radial voltage for each perturbation, it is possible to suppress an excessive loss fluctuation and to secure a perturbation width capable of searching for an optimum value. Specifically, in step S13 for calculating the optimum operation amount of the micromirror device 3a, the output light intensity fluctuation range ΔPp is calculated as in the first embodiment, and the micromirror device 3a is calculated by the above equation (7). A radial voltage parameter Vs ′ is obtained. This is used for the next perturbation pattern setting of the micromirror device 3a. For the micromirror device 3b, the output light intensity fluctuation range ΔPp is calculated in the same step S17, and the parameter Vs ′ of the radial voltage of the micromirror device 3b is obtained by the above equation (7). This is used for the next perturbation pattern setting of the micromirror device 3b. In this way, by repeating a series of perturbation pattern setting operation, optimum value moving operation, optimum value searching operation, and parameter updating operation, the driving voltage that maximizes the light intensity is calculated, and the optical connection strength loss of the optical switch is reduced. The optical connection strength can be stabilized within a predetermined allowable value.

  In the first and second embodiments described above, the case where there are two micromirror devices has been described as an example. However, an arbitrary wavelength is switched from input light as shown in FIG. 9 to be described later. Needless to say, the present invention can be applied to a wavelength selective switch that outputs from an output port. This wavelength selective switch will be described below.

  In FIG. 9, 210 is an input port, 211a and 211b are output ports, 212 is a micromirror array, 214 is a main lens, 215 is a reflective diffraction grating, 216 is a collimating lens, and 217a and 217b are output ports 211a and 211b, respectively. , 219 is a drive voltage determination unit, and 220 is a control device. The micromirror array 212 includes a plurality of micromirror devices 213a, 213b, and 213c arranged one-dimensionally.

  The input port 210 emits a wavelength multiplexed signal 221 obtained by multiplexing a plurality of optical signals having different wavelengths toward the main lens 214. The wavelength multiplexed signal 221 that has passed through the main lens 214 is incident on the reflection diffraction grating 215. The wavelength multiplexed signal 221 incident on the reflection diffraction grating 215 is reflected by the reflection diffraction grating 215, and is demultiplexed into a plurality of optical signals 222a, 222b, and 222c having different wavelengths. The demultiplexed optical signals 222a, 222b, and 222c pass through the main lens 214 again and enter predetermined micromirror devices 213a, 213b, and 213c, respectively.

  The optical signals 222a, 222b, and 222c are reflected by the mirrors of the corresponding micromirror devices 213a, 213b, and 213c, respectively, and then converted into optical signals 223a, 223b, and 223c that are collimated by the collimating lens 16, and the main lens 214 Then, the light enters the reflection diffraction grating 215. Each optical signal 223a, 223b, 223c is reflected by the reflection diffraction grating 215, and then enters the output port 211a, 211b of any one of the plurality of output ports 211 again through the main lens 214. In the example of FIG. 9, the optical signals 223a and 223c reflected by the micromirror devices 213a and 213c enter the output port 211a, and the optical signal 223b reflected by the micromirror device 213b enters the output port 211b.

  In this way, after the wavelength multiplexed signal 221 from the input port 210 is incident on the reflection diffraction grating 215 and demultiplexed into a plurality of optical signals, each of the demultiplexed optical signals is received by the corresponding micromirror devices 213a, 213b, and 213c. By making the light incident on the mirror and appropriately controlling the direction of each mirror by the control device 20 at this time, one or a plurality of sets of optical signals having one wavelength or a plurality of optical signals having different wavelengths are provided. A set can be extracted, combined for each set, and incident on desired output ports 211a and 211b.

  Here, the configuration of each of the micromirror devices 213a, 213b, and 213c is the same as that of the above-described micromirror devices 3a and 3b.

  Each output light measuring device 217a, 217b detects the intensity of the output light incident on the corresponding output port 211a, 211b and converts it into an electrical signal.

  Based on the intensity of the output light measured by the output light measurement devices 217a and 217b when the drive voltage determination unit 219 gives an instruction to the control device 5 to perturb the mirrors of the micromirror devices 213a, 213b, and 213c, A drive voltage for controlling the mirrors of the micromirror devices 213a, 213b, and 213c to an appropriate angle is determined so that the intensity of the output light becomes an optimum value.

  The control device 220 supplies a drive voltage to the micromirror devices 213a, 213b, and 213c based on an instruction from the drive voltage determination unit 215 to perturb each mirror or tilt each mirror to a predetermined tilt angle.

  Each micromirror device included in such a wavelength selective switch is perturbed by the same method as described above, and by detecting the light intensity of the output light at this time, the light intensity of the output light is maximized. The driving voltage can be calculated.

  The present invention can be applied to a device having a switching element such as a micromirror device.

  DESCRIPTION OF SYMBOLS 1a ... Input port, 1b ... Output port, 3a, 3b ... Micromirror device, 4 ... Output light measuring device, 5 ... Control device, 6 ... Drive part, 7 ... Detection part, 8 ... Control part, 9 ... Storage part, 81: switching unit, 82: perturbation pattern setting unit, 83: comparison / update unit, 84: manipulated variable generation unit, 85: error calculation correction unit

Claims (9)

At least one input port for inputting input light;
At least one output port for outputting output light;
At least one mirror device comprising a mirror rotatably supported with respect to the X axis and the Y axis orthogonal to each other, and an electrode disposed opposite to the mirror;
Deflecting said input light by a predetermined amount tilt the mirror by applying a driving voltage according to the mirror to the X axis and the Y manipulated variable rotating the axis, respectively V _x and V _y to the electrodes And a control unit that selectively enters the output port,
The controller is
A setting unit for setting a perturbation pattern composed of changes ΔV _x and ΔV _{y with} respect to the manipulated variables V _x and V _y , which varies with time;
A perturbation unit that modulates the manipulated variables V _x and V _y with the perturbation pattern to perturb the mirror;
A detector that detects the light intensity of the output light incident on the output port by the mirror;
The variation of the light intensity of the output light detected by the detector when the mirror is perturbed according to the perturbation pattern, the manipulated variables V _x and V _y, and the changes ΔV _x and ΔV _y are the most. An arithmetic processing unit that calculates new operation amounts V _x and V _y that give a tilt angle of the mirror in which strong light intensity is detected,
The setting unit
A perturbation pattern is set on the plane having the manipulated variables V _x and V _y as coordinate axes, and the changes ΔV _x and ΔV _y that vary with time take at least one value in each quadrant starting from the origin. An optical switch characterized by that. 2. The optical switch according to claim 1, wherein the perturbation pattern draws two circles that are circumscribed at the origin on the plane, with respect to the changes ΔV _x and ΔV _y that change with time according to a trigonometric function. The controller is
A storage unit for storing an allowable value of the loss change amount of the output light;
A fluctuation range calculation unit that calculates a fluctuation range of the light intensity of the output light detected by the detection unit when the mirror is perturbed according to the perturbation pattern;
The setting unit reduces the radius of the circle of the perturbation pattern used for the next perturbation when the variation width is larger than the allowable value, and the perturbation pattern used for the next perturbation when the variation width is smaller than the allowable value. The optical switch according to claim 2, wherein the radius of the circle is increased. The optical switch according to claim 1, wherein the new manipulated variables V _x and V _y take values on the perturbation pattern. The optical switch according to claim 4, wherein the setting unit uses the new operation amounts V _x and V _y as the starting points. The mirror device is composed of a first mirror device and a second mirror device,
The first mirror device deflects the input light input to the input port to enter the second mirror device,
6. The second mirror device according to claim 1, wherein the second mirror device deflects light incident from the first mirror device and selectively enters the output port. Light switch. At least one input port for inputting input light;
At least one output port for outputting output light;
At least one mirror device including a mirror rotatably supported with respect to the X axis and the Y axis orthogonal to each other, and an electrode disposed opposite to the mirror;
Deflecting said input light by a predetermined amount tilt the mirror by applying a driving voltage according to the mirror to the X axis and the Y manipulated variable rotating the axis, respectively V _x and V _y to the electrodes And a control unit that selectively enters the output port.
A setting step for setting a perturbation pattern consisting of changes ΔV _x and ΔV _{y with} respect to the manipulated variables V _x and V _y , which vary over time;
A perturbation step of perturbing the mirror by modulating the manipulated variables V _x and V _y with the perturbation pattern;
A detection step of detecting the light intensity of the output light incident on the output port by the mirror;
The variation of the light intensity of the output light detected by the detection step when the mirror is perturbed according to the perturbation pattern, the manipulated variables V _x and V _y, and the changes ΔV _x and ΔV _y are the most. An arithmetic processing step for calculating new manipulated variables V _x and V _y that give a tilt angle of the mirror in which a strong light intensity is detected,
In the setting step, the changes ΔV _x and ΔV _y that vary with time on a plane having the manipulated variables V _x and V _y as coordinate axes take at least one value in each quadrant with the origin as the start point and the end point. A method of controlling an optical switch, characterized in that a perturbation pattern is set. At least one input port for inputting input light;
At least one output port for outputting output light;
A mirror supported to be rotatable with respect to the X axis and a Y axis orthogonal to the X axis, and an electrode disposed opposite to the mirror, and applying a driving voltage corresponding to the operation amount to the electrode; The first mirror device and the second mirror device that deflect the input light input to the input port by selectively tilting the mirror and selectively enter the output port, and the first mirror device and Applying a driving voltage corresponding to operation amounts V _x and V _y for rotating the mirror of the second mirror device about the X axis and the Y axis to tilt the mirror by a predetermined amount. And a control unit that deflects the input light and selectively enters the output port.
A first step of setting a perturbation pattern consisting of changes ΔV _x and ΔV _{y with} respect to the manipulated variables V _x and V _y , which varies over time;
A second step of perturbing the mirror of the first mirror device by modulating the manipulated variables V _x and V _y with the perturbation pattern;
A third step of detecting light intensity of output light output from one output port when input light from one input port is output when the mirror of the first mirror device is perturbed;
When the mirror of the first mirror device is perturbed according to the perturbation pattern, the variation in the light intensity of the output light detected by the third step, the manipulated variables V _x and V _y, and the From the changes ΔV _x and ΔV _y , new operation amounts V _x and V _y that give the tilt angle of the mirror where the strongest light intensity is detected are calculated, and the tilt angle of the mirror of the first mirror device is calculated. A fourth step to correct;
A fifth step of modulating the manipulated variables V _x and V _y with the perturbation pattern to perturb the mirror of the second mirror device;
A sixth step of detecting light intensity of output light output from one output port when input light from one input port is output when the mirror of the second mirror device is perturbed;
When the mirror of the second mirror device is perturbed according to the perturbation pattern, the fluctuation of the light intensity of the output light detected by the fifth step, the manipulated variables V _x and V _y, and the New manipulated variables V _x and V _y that give the tilt angle of the mirror where the strongest light intensity is detected are calculated from the changes ΔV _x and ΔV _y, and the tilt angle of the mirror of the second mirror device is calculated. A seventh step of correcting, and
In the first step, the changes ΔV _x and ΔV _y that vary with time on a plane with the manipulated variables V _x and V _y as coordinate axes are at least one value in each quadrant starting from the origin and ending. Set the perturbation pattern to take
A method for controlling an optical switch, characterized in that the second to seventh steps are repeated. In the fifth step, a driving voltage corresponding to the new operation amounts V _x and V _y calculated in the fourth step is applied to the electrode of the first mirror device, Perturbing the mirror of the second mirror device;
In the second step, a driving voltage corresponding to the new operation amounts V _x and V _y calculated in the seventh step is applied to the electrode of the second mirror device, The method of controlling an optical switch according to claim 8, wherein the mirror of the first mirror device is perturbed.

Images