JP2008096673A - Optical switch, optical switch control method, optical switch control program, and recording medium - Google Patents

Abstract

A voltage range for perturbation is efficiently set.
A comparison unit acquires a light intensity of output light measured by an output light measurement device through a detection unit and detects a loss change amount ΔP. The width setting unit 81 sets the width ΔV based on the loss change amount ΔP. This eliminates the need for trial and error with respect to a preset value, so that the width ΔV can be set in a short time. In addition, since the mirror can be perturbed closer to the center of the intensity distribution of the optical signal, the connection loss can be stabilized. Therefore, the width ΔV can be set efficiently.
[Selection] Figure 1

Description

  The present invention relates to an optical switch having a deflecting element such as a mirror, a control method for the optical switch, a control program for the optical switch, and a recording medium.

  As one technique for realizing an optical switch, a technique using a deflecting element such as a micromirror has been proposed (see, for example, Non-Patent Document 1). A conventional optical switch using a micromirror is shown in FIG.

  The optical switch shown in FIG. 7 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. 7 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 this input port 1a, and its traveling direction is changed. 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, and the arbitrary input port 1a and output port 1b arranged two-dimensionally Can be connected.

  The most characteristic components of such an optical switch are micromirror devices 3a and 3b having mirrors. Conventionally, as shown in FIGS. 8 and 9, 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 (for example, (Refer nonpatent literature 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 can rotate about the movable frame rotation axis X of FIG. 8 passing through the pair of torsion springs 211a and 211b. Similarly, the pair of torsion springs 221 a and 221 b connect the movable frame 220. The mirror 230 can rotate about the mirror rotation axis Y of FIG. 8 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. 9 is configured. In such a micromirror device, the mirror 230 is grounded, a positive driving voltage is applied to the electrodes 340a to 340d, and an asymmetric potential difference is generated between the electrodes 340a to 340d, thereby causing the electrostatic attraction force of the mirror 230. And the mirror 230 can be rotated 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, pp1360-1362

  In the optical switch described above, a control device (not shown) that controls the tilt angle of the mirror 230 supplies a periodically changing drive voltage to the micromirror devices 3a and 3b to perturb (vibration) the mirror 230. The intensity of the output light is measured by an output light measuring device (not shown) provided on the output end side of the output port 1b, and the relationship between the drive voltage and the intensity of the output light is obtained to determine the optimum of the mirror 230. In general, an optimum driving voltage (for example, a driving voltage at which the intensity of the output light is optimum) for obtaining a proper inclination angle is obtained.

  Perturbation is performed using a range of drive voltages to be changed, that is, a range of drive voltages to be changed in advance, trial and error by experiment to determine which value is optimal, and using this value. It was. This value is often performed using the same value in the other micromirror devices 3a and 3b.

  However, in the case where the optical switch has a large number of micromirror devices 3a and 3b, it took an enormous amount of time to experiment with a plurality of values in order to obtain the drive voltage width for perturbation. Further, when the same value set for all the micromirror devices 3a and 3b is used, the time required to obtain the optimum drive voltage width is shortened, but the individual micromirror devices 3a and 3b have voltage-angle characteristics. Therefore, even if the same drive voltage is applied, the perturbation width differs, and as a result, it becomes difficult to ensure the stability of the connection loss in the optical switch.

  Accordingly, an object of the present invention is to provide an optical switch, an optical switch control method, an optical switch control program, and a recording medium that can efficiently set a voltage range for perturbation.

  In order to solve the problems as described above, an optical switch according to the present invention is rotatably supported by at least one input port for inputting input light and at least one output port for outputting output light. A mirror and an electrode disposed opposite to the mirror are provided, and input light input to the input port is deflected and selectively incident on the output port by a mirror that rotates according to a control voltage applied to the electrode. A mirror device, a first setting unit for setting a first range for changing the control voltage, a perturbation unit for perturbing the mirror by changing the control voltage within the first range, and a change in the first range An update unit that sets a second range based on a change in power of output light from one output port when the mirror is rotated, and updates the first range of the first setting unit; Perturb the mirror And a second setting unit that sets a voltage that optimizes the power of the output light as a control voltage for one output port based on the power of the output light that is sometimes output from one output port. And

  In the optical switch, the updating unit outputs the first range when the magnitude of the change in the power of the output light when the control voltage is changed in the first range is larger than the first threshold value. The first setting unit updates the control voltage again in the updated first range, including the voltage at which the light power is maximized and having a width smaller than the width of the first range. May be changed.

  In the optical switch, the updating unit further has a second change in the magnitude of the change in the power of the output light when the control voltage is changed in the first range. If it is smaller, the first range may be updated to a voltage range including a voltage at which the power of the output light is maximized and having a width larger than the width of the first range.

  In the optical switch, when the updating unit updates the first range a predetermined number of times, the updating unit may set the first range at that time as the second range. In addition, the update unit changes the output light power when the control voltage is changed in the first range before the update and the change in the output light power when the control voltage is changed in the first range after the update. When the difference in size is smaller than a predetermined value, one of the first range before update and the first range after update may be set as the second range.

  In the optical switch, the update unit sets a second range for the control voltages in the X-axis direction and the Y-axis direction substantially parallel to the mirror surface of the mirror and orthogonal to each other, and the perturbation unit is in the X-axis direction. In a plane defined by the second range and the second range in the Y-axis direction, the control voltage may be changed spirally or the control voltage may be changed zigzag.

  In the optical switch, a plurality of mirror devices may be provided, and the updating unit may set the second range for each mirror device.

  The optical switch control method according to the present invention includes at least one input port for inputting input light, at least one output port for outputting output light, a mirror that is rotatably supported, and the mirror. And a mirror device that deflects input light input to the input port by a mirror that rotates according to a control voltage applied to the electrode and selectively enters the output port. A method for controlling an optical switch, the first setting step for setting a first range for changing the control voltage, the perturbation step for perturbing the mirror by changing the control voltage within the first range, The second range is set based on the change in the power of the output light from one output port when the mirror is rotated by changing the range of 1, and the first range of the first setting unit is updated. You And a second step of setting a voltage that optimizes the power of the output light as a control voltage for one output port based on the power of the output light output from one output port when the mirror is perturbed And a setting step.

  Further, an optical switch control program according to the present invention includes at least one input port for inputting input light, at least one output port for outputting output light, a mirror that is rotatably supported, and the mirror. And a mirror device that deflects input light input to the input port by a mirror that rotates according to a control voltage applied to the electrode and selectively enters the output port. An optical switch control program, comprising: a first setting step for setting a first range for changing a control voltage in a computer; and a perturbation step for perturbing a mirror by changing the control voltage within the first range. And the second range is set based on the change in the power of the output light from one output port when the mirror is rotated in the first range. Based on the update step for updating the first range of the setting unit and the power of the output light output from one output port when the mirror is perturbed, one voltage is output to optimize the output light power. And a second setting step of setting as a control voltage for the port.

  The program according to the present invention is characterized in that the control program for the optical switch is recorded.

  According to the present invention, by setting the second range based on the change in the power of the output light from one output port when the mirror is rotated by changing the control voltage in the first range, Since the setting can be performed in a short time and the connection loss can be stabilized, as a result, the voltage range for the perturbation can be set efficiently.

  Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, the same names and symbols are assigned to the same components as those described in the background art section with reference to FIGS.

[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 configuration in which a part of the output light is cut out and the intensity of the output light is measured by a light receiving element such as a photodiode can be considered.

  The control device 5 includes a drive unit 6, a detection unit 7, a control unit 8, and a storage unit 9.

  The drive unit 6 supplies a drive voltage to the micromirror devices 3a and 3b based on an instruction from the control unit 8 to incline the mirror 230 at a predetermined angle, or gives a minute change to the drive voltage to move the mirror 230. Perturb.

  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 overall operation of the optical switch 10, and includes a range setting unit 81, a comparison unit 82, an update unit 83, a perturbation unit 84, an optimum value detection unit 85, and switching. And at least a portion 86.

  The range setting unit 81 is a functional unit that sets a swing width when the perturbation unit 84 perturbs the mirror 230 and changes the drive voltage within the swing width. Here, the fluctuation width is a width ΔV [V] indicating a range of a drive voltage (hereinafter referred to as “perturbation voltage”) that is periodically changed to be supplied to the micromirror devices 3 a and 3 b to perturb the mirror 230. Means that. The perturbation means that the mirror 230 is vibrated by supplying a perturbation voltage to each electrode of the micromirror devices 3a and 3b. For example, when there are four electrodes 340a to 340d as shown in FIGS. 8 and 9, the mirror 230 is perturbed by supplying a perturbation voltage to each electrode. The width ΔV set by the range setting unit 81 is stored in the storage unit 9.

The comparison unit 82 detects the loss change amount ΔP based on the light intensity of the output light detected by the detection unit 7, and the loss change amount ΔP is a predetermined value, that is, the loss change amount stored in the storage unit 9. It is compared whether or not the maximum specified value ΔP _max and the loss change amount minimum specified value ΔP _min are exceeded. The comparison result is output to the update unit 83.

  The update unit 83 updates the range of the width ΔV set by the range setting unit 81 based on the comparison result by the comparison unit 82. The updated width ΔV is output to the range setting unit 81.

  The perturbation unit 84 connects each mirror 230 based on the width ΔV [V] set by the range setting unit 81 when connecting the optical path between the arbitrary micromirror device 3a and the arbitrary micromirror device 3b. A perturbation voltage for perturbation is set, and this perturbation voltage is supplied to the micromirror devices 3a and 3b.

  The optimum value detection unit 85 determines the optical path between the arbitrary micromirror device 3a and the arbitrary micromirror device 3b 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 perturbation unit 84. A drive voltage (hereinafter referred to as “operating voltage”) that realizes an optimum tilt angle of each mirror 230 at the time of connection is detected.

  The switching unit 86 connects the corresponding micromirror device 3a via the drive unit 6 based on the operating voltage stored in the storage unit 9 when connecting the optical path between the arbitrary micromirror device 3a and the arbitrary micromirror device 3b. , 3b is supplied with an operating voltage.

The storage unit 9 includes a width ΔV set by the range setting unit 81, a preset loss change amount maximum prescribed value ΔP _max and a loss change amount minimum prescribed value ΔP _min , a perturbation voltage set by the perturbation unit 84, and A program or the like for realizing the operation of the optical switch 10 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 Disc Drive), an input device that detects input of information from the outside such as a keyboard, a mouse, a pointing device, a button, and a touch panel, I / F devices that send and receive various types of information via communication lines such as the Internet, LAN (Local Area Network), WAN (Wide Area Network), etc., and CRT (Cathode Ray Tube), LCD (Liquid Crystal Display) or FED The computer includes a display device such as (Field Emission Display) and a program installed in the computer. That is, the hardware device and software cooperate to control the above hardware resources by a program, and the above-described drive unit 6, detection unit 7, control unit 8, and storage unit 9 are realized. Note that the program may be provided in a state of being recorded on a recording medium such as a flexible disk, a CD-ROM, a DVD-ROM, or a memory card.

[Width setting operation]
Next, the width setting operation by the control device 5 will be described in detail with reference to FIG. This width setting operation is an operation for setting the width ΔV of the perturbation voltage supplied to the micromirror devices 3a and 3b in order to perturb the mirror 230. In the following, an example in which the width ΔV of the perturbation voltage supplied to an arbitrary micromirror device 3a is set will be described.

The range setting unit 81 of the control unit 8 sets the initial value V ₀ and the width ΔV of the drive voltage supplied to the electrodes 340a to 340d of the micromirror device 3a when setting the width ΔV of the arbitrary micromirror device 3a. (Step S1). The initial value V ₀ and the width ΔV are stored in the storage unit 9 in advance.

When the initial value V ₀ and the width ΔV are set, the range setting unit 81 supplies a driving voltage based on them to the electrodes 340a to 340d of the micromirror device 3a via the driving unit 6 (step S2). Here, the micromirror device 3a, as shown in FIG. 3 (a), the drive voltage varies within the range of the width [Delta] V [V] around the initial value V ₀ is supplied. Specifically, a drive voltage that changes from (−1/2) ΔV [V] to (1/2) ΔV [V], that is, from V ₁ [V] to V ₂ [V] is supplied. Such a drive voltage is supplied independently to each direction of the movable frame rotation axis X or the mirror rotation axis Y. Therefore, when the mirror 230 of the micromirror device 3a can be tilted in the biaxial directions of X and Y, the setting operation of the width ΔV is performed for each axis.

  At this time, the range setting unit 81 supplies a predetermined operating voltage to an arbitrary micromirror device 3b, tilts the mirror 230 to a predetermined angle, and keeps the optical path connected to the micromirror device 3a. In addition, an optical signal having a predetermined light intensity distribution is input from the outside toward the micromirror device 3a from the input port 1a.

When the drive voltage is supplied, the comparison unit 82 acquires the light intensity of the output light measured by the output light measurement device 4 via the detection unit 7, and detects the loss change amount ΔP (step S3). The loss change amount ΔP means a difference in light intensity measured by the output light measuring device 4 when the driving voltage set by the range setting unit 81 is supplied to the micromirror device 3a and the mirror 230 is tilted. To do. For example, as shown in FIG. 3A, when an optical signal having an intensity distribution represented by the symbol a is input, the loss when a drive voltage having a width ΔV is supplied with the initial value V ₀ as the center. The change amount ΔP is a difference between the light intensity I ₁ when the drive voltage V ₁ [V] is supplied and the light intensity I ₂ when the drive voltage V ₂ [V] is supplied.

When the loss change amount ΔP is detected, the comparison unit 82 confirms whether or not the loss change amount ΔP exceeds the loss change amount maximum specified value ΔP _max (step S4). The loss change maximum specified value ΔP _max is stored in advance in the storage unit 9 together with the loss change maximum specified value ΔP _min . These values are freely set as appropriate based on the shape and arrangement of the micromirror device.

When the loss change amount ΔP exceeds the loss change amount maximum specified value ΔP _max (step S4: YES), the update unit 83 determines that the deflection width of the mirror 230 is large, and decreases the value of the width ΔV (step). S8).

On the other hand, when the loss change amount ΔP does not exceed the loss change amount maximum specified value ΔP _max (step S4: NO), the comparison unit 82 determines whether or not the loss change amount ΔP is smaller than the loss change amount minimum specified value ΔP _min . Is confirmed (step S5). When the loss change amount ΔP is smaller than the loss change amount minimum prescribed value ΔP _min (step S5: YES), the updating unit 83 determines that the deflection width of the mirror 230 is small and increases the value of the width ΔV (step S9). . On the other hand, when the loss change amount ΔP is greater than the loss change amount minimum prescribed value ΔP _min (step S5: NO), the updating unit 83 does not change the value of the width ΔV (step S6).

  When the width ΔV is updated as described above, the range setting unit 81 checks whether or not the width ΔV has been updated a predetermined number of times (step S7).

If not performed for a predetermined number of times (step S7: NO), the update unit 83 updates the value of the initial value V ₀ (step S10), and the process returns to step S2. For example, as shown in FIG. 3A, when the initial value is ΔV ₀ , the width is ΔV, and the driving voltage at which the light intensity becomes maximum within the width ΔV is V ₂ , the updating unit 83 performs the operation shown in FIG. ), The new initial value V ₀ ′ is set to a drive voltage at which the light intensity is maximized, that is, V ₂ , so that the newly set width ΔV includes the maximum value of the light intensity in the current measurement. Set to. At this time, when the new width is set to ΔV ′, the driving voltage having a width ΔV ′ centered on V ₀ ′, that is, the driving voltage in the range from the voltage V ₃ to the voltage V ₄ is set in step S 2. Supplied by As a result, the mirror 230 can be perturbed at a position closer to the center of the intensity distribution of the optical signal.

  When the comparison is performed a predetermined number of times (step S7: YES), the range setting unit 81 sets the current width ΔV to the width ΔV (step S8).

  As described above, according to the present embodiment, by setting the width ΔV based on the loss change amount ΔP, it is not necessary to perform trial and error on a preset value, so that the width ΔV can be set in a short time. It becomes possible. Further, since the mirror 230 can be perturbed closer to the center of the intensity distribution of the optical signal, the connection loss can be stabilized. Therefore, the width ΔV can be set efficiently.

  In the present embodiment, the value of the width ΔV when the loss change amount ΔP is compared a predetermined number of times is set as the width ΔV, but the setting method of the width ΔV is not limited to this. For example, when the difference between the loss change amount ΔP and the loss change amount ΔP at the previous comparison is within a predetermined value, either the previous width ΔV or the current width ΔV is set as the width ΔV. You may make it do.

If the value of the loss change amount ΔP does not exceed the minimum loss change amount prescribed value ΔP _min even after the comparison is performed a predetermined number of times, the loss change amount ΔP becomes larger than the maximum loss change amount prescribed value ΔP _max. The width ΔV may be increased. Thereby, when the mirror 230 is perturbed, output light having a light intensity of a predetermined value or more can be obtained.

[Perturbation operation]
Next, the perturbation operation by the perturbation unit 84 will be described.

  First, when the width ΔV is set by the method described above, the perturbation unit 84 sets a perturbation voltage based on the width ΔV. Specifically, a value obtained by dividing the set width ΔV at a predetermined interval is defined as a perturbation voltage.

For example, when the width ΔV is set to ΔV _X1 , the Y-axis direction is ΔV _Y1 , the X-axis direction of the micromirror device 3 b is ΔV _X2 , and the Y-axis direction is ΔV _Y2 , respectively. A case will be described in which the perturbation voltage is set only to the value of 25 points in a spiral shape. The X axis and the Y axis are set so as to be substantially parallel to the mirror 230 and orthogonal to each other.

In the case of the micromirror device 3a, as shown in FIG. 4 (a), the perturbation voltage is obtained by dividing the range at a predetermined interval in consideration of the number of spirals in the range consisting of ΔV _X1 and ΔV _Y1. Set. Similarly, in the case of the micromirror device 3b, as shown in FIG. 4B, by dividing the range at a predetermined interval in consideration of the number of spirals within the range consisting of ΔV _X2 and ΔV _Y2. Set the perturbation voltage. In addition, each point of the perturbation voltage shown in FIGS. 4A and 4B indicates the drive voltage in the X direction and the Y direction. At this time, as shown in FIG. 4C, the electrode 360a is positive in the X-axis direction, the electrode 360c is negative in the X-axis direction, the electrode 360b is positive in the Y-axis direction, and the negative direction is in the Y-axis direction. It is assumed that an electrode 360d is provided.

  Each perturbation voltage is assigned to electrodes 340a-340d according to its value. For example, in the case of the perturbation voltage at the point indicated by symbol b in FIG. 4A, that is, X1 = 1 [V], Y1 = −0.4 [V], the electrode 360a disposed in the positive direction of the X axis. 1 [V], and a drive voltage of 0.4 [V] is applied to the electrode 360d disposed in the negative direction of the Y-axis.

  Optimum connection loss of the propagating optical signal is small when connecting the optical path between the micromirror device 3a and the micromirror device 3b in a state where an optical signal is input from the input port 1a to the micromirror device 3a from the outside. In order to search for a correct operating voltage, the perturbation unit 84 starts perturbation at the set perturbation voltage. Further, the perturbation voltage of the micromirror device 3b is fixed to the outermost shell point, and the mirror 230 is perturbed while sequentially moving the 25 points where the perturbation voltage of the micromirror device 3a is set. 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 the perturbation voltage of the micromirror device 3a is sequentially moved with respect to the set 25 points, the perturbation voltage of the micromirror device 3b is moved to the next point, and the 25 points with the perturbation voltage of the micromirror device 3a are sequentially moved. Each mirror 230 is perturbed. When the micromirror device 3b is moved to the last value of the perturbation voltage, the light intensity of 625 points is stored in the storage unit 9, as shown in FIG. The optimum value detection unit 85 connects the perturbation voltage when the light intensity is maximum from among the 625 points of light intensity stored in the storage unit 9 when connecting the optical path between the micromirror device 3a and the micromirror device 3b. Set as the optimal operating voltage.

  As described above, according to the present embodiment, the spiral perturbation voltage is set based on the width ΔV set by the range setting unit 81, and the optimum operating voltage is detected based on the perturbation voltage. By starting the search from the outermost shell, the amount of movement when the vicinity of the initial position is the optimum value can be reduced, so that high speed can be realized.

  In the present embodiment, since the width ΔV of the mirror 230 of the micromirror devices 3a and 3b can be set for each micromirror device, the optimum operation compared with the case where the width ΔV is fixed in advance. The voltage can be searched efficiently.

  In the present embodiment, the perturbation voltage is set in a spiral shape within a predetermined range based on the width ΔV. However, as shown in FIGS. 6A and 6B, the perturbation voltage is zigzag in a substantially N shape. You may make it set to. Even in this case, it is possible to realize a high-speed search for the optimum operating voltage.

  In this embodiment, the operating voltage is set so that the light intensity of the output light is maximized, but the light intensity of the output light is, for example, a variable optical attenuator (VOA). The operating voltage may be set so that becomes a predetermined value.

  The present invention can be applied to an optical element such as an optical switch that perturbs a changing element such as a mirror by applying a periodically changing drive voltage.

(A) is a block diagram showing the configuration of the optical switch of the present invention, (b) is a block diagram showing the configuration of the control device. It is a flowchart which shows width setting operation | movement. It is a figure explaining width setting operation. (A), (b) is a figure explaining a perturbation voltage, (c) is a figure which shows typically arrangement | positioning of an electrode. It is a figure which shows an example of the relationship between the frequency | count of search and light intensity. (A), (b) is a figure explaining the other example of a perturbation voltage. 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.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a ... Input port, 1b ... Output port, 3a ... Input side micromirror device, 3b ... Output side micromirror device, 4 ... Output light measuring device, 5 ... Control device, 6 ... Drive part, 7 ... Detection part, 8 ... Control unit, 9 ... storage unit, 10 ... optical switch, 81 ... range setting unit, 82 ... comparison unit, 83 ... update unit, 84 ... perturbation unit, 85 ... optimum value detection unit, 86 ... switching unit.

Claims (11)

At least one input port for inputting input light;
At least one output port for outputting output light;
A mirror that is rotatably supported, and an electrode disposed opposite to the mirror, and deflects input light input to the input port by the mirror that rotates according to a control voltage applied to the electrode. A mirror device that selectively enters the output port;
A first setting unit for setting a first range for changing the control voltage;
A perturbation unit for perturbing the mirror by changing the control voltage within the first range;
A second range is set based on a change in power of output light from one output port when the mirror is rotated by changing in the first range, and the second setting of the first setting unit is performed. An update unit for updating the range of 1;
A voltage that optimizes the power of the output light is set as a control voltage for the one output port based on the power of the output light output from the one output port when the mirror is perturbed. An optical switch comprising: a setting unit. When the magnitude of the change in power of the output light when the control voltage is changed in the first range is greater than a first threshold, the update unit sets the first range to the Including a voltage at which the power of the output light is maximized, and updated to a voltage range having a width smaller than the width of the first range;
The optical switch according to claim 1, wherein the first setting unit changes the control voltage again in the updated first range. The updating unit further includes a second threshold value that is smaller than the first threshold value when the control voltage is changed in the first range. The first range is updated to a voltage range including a voltage at which the power of the output light is maximized and having a width larger than the width of the first range. The optical switch according to claim 1 or 2. 4. The update unit according to claim 1, wherein, when the first range is updated a predetermined number of times, the first range at that time is set as the second range. 5. Light switch. The updating unit is configured to convert the output light power when the control voltage is changed in the first range before the update and the output light power when the control voltage is changed in the first range after the update. When the difference in magnitude of the change is smaller than a predetermined value, any one of the first range before the update and the first range after the update is set as the second range. The optical switch according to any one of claims 1 to 3. The update unit sets the second range for the control voltages in the X-axis direction and the Y-axis direction that are substantially parallel to the mirror surface of the mirror and orthogonal to each other,
2. The perturbation unit changes the control voltage in a spiral shape within a plane defined by the second range in the X-axis direction and the second range in the Y-axis direction. 6. The optical switch according to any one of 1 to 5. The update unit sets the second range for the control voltages in the X-axis direction and the Y-axis direction that are substantially parallel to the mirror surface of the mirror and orthogonal to each other,
The perturbation unit changes the control voltage in a zigzag manner within a plane defined by the second range in the X-axis direction and the second range in the Y-axis direction. 6. The optical switch according to any one of 5 above. A plurality of the mirror devices are provided,
The optical switch according to claim 1, wherein the update unit sets the second range for each mirror device. At least one input port for inputting input light;
At least one output port for outputting output light;
A mirror that is rotatably supported, and an electrode disposed opposite to the mirror, and deflects input light input to the input port by the mirror that rotates according to a control voltage applied to the electrode. An optical switch control method comprising: a mirror device that selectively enters the output port;
A first setting step for setting a first range for changing the control voltage;
A perturbation step of perturbing the mirror by changing the control voltage within the first range;
A second range is set based on a change in power of output light from one output port when the mirror is rotated by changing in the first range, and the second setting of the first setting unit is performed. An update step for updating the range of 1;
A voltage that optimizes the power of the output light is set as a control voltage for the one output port based on the power of the output light output from the one output port when the mirror is perturbed. An optical switch control method comprising: a setting step. At least one input port for inputting input light;
At least one output port for outputting output light;
A mirror that is rotatably supported, and an electrode disposed opposite to the mirror, and deflects input light input to the input port by the mirror that rotates according to a control voltage applied to the electrode. An optical switch control program comprising: a mirror device that selectively enters the output port;
On the computer,
A first setting step for setting a first range for changing the control voltage;
A perturbation step of perturbing the mirror by changing the control voltage within the first range;
A second range is set based on a change in power of output light from one output port when the mirror is rotated by changing in the first range, and the second setting of the first setting unit is performed. An update step for updating the range of 1;
A voltage that optimizes the power of the output light is set as a control voltage for the one output port based on the power of the output light output from the one output port when the mirror is perturbed. A control program for an optical switch, characterized in that a setting step is executed.   A recording medium on which the control program for the optical switch according to claim 10 is recorded.

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