JP2005189548A - Optical switch apparatus and calibration method for optical switch apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical switch apparatus having a stable characteristic. <P>SOLUTION: The optical switch apparatus 100 has: one inputting optical fiber 112; a plurality of outputting optical fibers 114 that output light; one detecting optical fiber 116; an optical switch optical system composed of a collimator lens 122, a convergent lens 124, a convergent lens 126, a convex lens 132, a convex lens 134, a grating 136 and a movable mirror 140; a memory 176 which holds a control value relating to the movable mirror 140; a mirror drive circuit 180 which drives the movable mirror 140 in accordance with the control value; a PD 172 optically coupled to the detecting optical fiber 116; and an adjusting circuit 178 which can read and write the control value stored in the memory 176 and can adjust the control value on the basis of an output from the PD 172. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical switch device that switches an optical connection between an input optical fiber and an output optical fiber by deflecting a light beam with a movable mirror.

US Patent Application Publication No. 2002 / 0196520A1 discloses an optical switch device. In this optical switch device, an output optical fiber to be output can be switched by demultiplexing a wavelength-multiplexed light beam input from an input optical fiber by a grating and deflecting it by a movable mirror corresponding to each wavelength. .
US Patent Application Publication No. 2002 / 0196520A1

  In order to couple the input optical fiber and the output optical fiber with low loss, it is necessary to control the deflection angle of the movable mirror that deflects the light beam with high accuracy. The aforementioned optical switch device does not consider this point. For this reason, when an angle control error occurs due to a change in drive characteristics of the movable mirror due to a factor over time or a change in environment, there is a possibility that light loss may increase.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide an optical switch device having stable characteristics.

  One aspect of the present invention is an optical switch device, and includes at least one input optical fiber, at least one output optical fiber, and a movable mirror for directing a light beam from the input optical fiber to the output optical fiber. A control information holding means for holding a control value related to the attitude control of the movable mirror, a driving means for driving the movable mirror based on the control value, a light quantity detecting means for detecting the light quantity of the light beam, and a light quantity detecting means. The control value is adjusted based on the output, the control value necessary for directing the light beam to the optical fiber for output is obtained based on the adjusted control value, and the control information held in the control information holding means is obtained with the obtained control value Adjusting means for updating the value.

  The present invention includes, in part, at least one input optical fiber, at least one output optical fiber, a movable mirror for directing a light beam from the input optical fiber to the output optical fiber, and a control value of the movable mirror. Is a method for calibrating an optical switch device comprising a control information holding means for holding the light and a drive means for driving the movable mirror based on the control value, and a step of detecting the light quantity of the light beam from the input optical fiber; Adjusting the control value of the movable mirror based on the detected light amount; obtaining the control value for controlling the movable mirror so as to direct the light beam toward the output optical fiber based on the adjusted control value; And a step of updating the control value held in the control information holding means with the obtained control value.

  According to the present invention, an optical switch device having stable characteristics is provided.

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

First Embodiment The present embodiment is directed to an optical switch device that can switch a wavelength-multiplexed light beam for each wavelength. FIG. 1 shows the configuration of the optical switch device according to the first embodiment of the present invention.

  As shown in FIG. 1, the optical switch device 100 according to the present embodiment outputs a single input optical fiber 112 to which a wavelength-multiplexed light beam (light including a plurality of wavelength components) is input, and outputs light. A plurality of output optical fibers 114, a single detection optical fiber 116 having optical characteristics similar to those of the output optical fiber 114, and a collimating lens for converting a divergent light beam emitted from the input optical fiber 112 into a parallel light beam 122, the same number of converging lenses 124 as the output optical fiber 114 for converting the parallel light beam directed to the output optical fiber 114 into a convergent light beam, and the convergence for converting the parallel light beam directed to the detection optical fiber 116 into a convergent light beam. And a lens 126.

  The optical switch device 100 further includes a convex lens 132 that converts the parallel light beam from the collimating lens 122 into a convergent light beam, a convex lens 134 that converts the divergent light beam once converged from the convex lens 132 into a parallel light beam, and a convex lens 134. The grating 136 deflects the parallel light beam in different directions for each wavelength component.

  The grating 136 deflects the wavelength-multiplexed incident light beam in different directions for each wavelength component. The parallel light beam deflected by the grating 136 enters the convex lens 134 and is converted into a convergent light beam.

  The optical switch device 100 further includes a plurality of movable mirrors 140. The plurality of movable mirrors 140 are aligned in a line along the diffraction direction by the grating 136. The number of movable mirrors 140 corresponds to the type of wavelength multiplexed in the light beam. In other words, the optical switch device 100 has the same number of movable mirrors 140 as the types of wavelengths demultiplexed by the grating 136.

  The plurality of output optical fibers 114 are aligned along the deflection direction of the light beam by the movable mirror 140, and the detection optical fibers 116 are arranged in the same row as the output optical fibers 114. That is, the output optical fiber 114 and the detection optical fiber 116 are arranged in a line along the deflection direction of the light beam by the movable mirror 140.

  Therefore, each of the movable mirrors 140 can direct the convergent light beam from the convex lens 134 to one of the output optical fiber 114 and the detection optical fiber 116 by changing the deflection angle thereof.

  That is, the collimating lens 122, the converging lens 124, the converging lens 126, the convex lens 132, the convex lens 134, the grating 136, and the movable mirror 140 transmit a light beam between the input optical fiber 112, the output optical fiber 114, and the detection optical fiber 116. An optical switch optical system for coupling is configured.

  As shown in FIG. 1, the optical switch device 100 further drives the movable mirror 140 based on the control value and a memory 176 that is a control information holding unit that holds a control value related to the attitude control of the movable mirror 140. A mirror driving circuit 180 as a driving means, a photodetector 172 optically coupled to the optical fiber for detection 116, and an adjusting circuit 178 as an adjusting means for adjusting a control value based on the output of the photodetector 172. Have.

  Although not limited to this, the photodetector 172 includes, for example, a photodiode (PD). The PD 172 constitutes a light amount detection means for detecting the light amount of the light beam in cooperation with the detection optical fiber 116 and the converging lens 126.

  In the present embodiment, the control value related to the attitude control of the movable mirror 140 is a drive electric signal value. The adjustment circuit 178 can read and write the drive voltage value stored in the memory 176 and can adjust the drive voltage value applied to the mirror drive circuit 180 based on the output of the PD 172.

  In the optical switch device 100, a wavelength-multiplexed light beam, that is, light including a plurality of wavelength components is input to the input optical fiber 112. The light beam input to the input optical fiber 112 is emitted from the input optical fiber 112 as a divergent light beam. The divergent light beam emitted from the input optical fiber 112 is converted into a parallel light beam by the collimator lens 122. The parallel light beam from the collimating lens 122 is converted into a convergent light beam by the convex lens 132. This convergent light beam once converges and then becomes a divergent light beam. This divergent light beam is converted into a parallel light beam by the convex lens 134 and is incident on the grating 136. The light beam incident on the grating 136 is deflected in different directions for each wavelength component by the diffraction action of the grating 136 and is divided into a plurality of light beams having different wavelengths.

  Each of the plurality of light beams is converted into a convergent light beam by the convex lens 134 and directed to the corresponding movable mirror 140. The convergent light beam traveling toward the movable mirror 140 is converged near the movable mirror 140 and reflected by the movable mirror 140.

  The movable mirror 140 can change the deflection angle around one axis within a predetermined range. Thereby, the direction of the light beam reflected by the movable mirror 140 can be adjusted. As a result, the light beam reflected by the movable mirror 140 can be directed to any one of the plurality of output optical fibers 114 and detection optical fibers 116.

  The deflection angle of the movable mirror 140 is controlled by the mirror drive circuit 180 according to the drive voltage value stored in the memory 176. Therefore, the drive voltage value necessary for directing the light beam deflected by the movable mirror 140 to the output optical fiber 114 and the detection optical fiber 116 is stored in the memory 176, so that the coupling destination of the light beam can be freely set. Can be switched to.

  The light beam reflected by the movable mirror 140 is converted into a parallel light beam by the convex lens 134. The parallel light beam is deflected by the grating 136 and then converted into a convergent light beam by the convex lens 134. This convergent light beam once converges and then becomes a divergent light beam, which is converted into a parallel light beam by the convex lens 132. This parallel light beam is converted into a convergent light beam by the converging lens 124 and is incident on the output optical fiber 114, or is converted into a convergent light beam by the converging lens 124 and is incident on the detection optical fiber 116.

  The light beam incident on the output optical fiber 114 is output from the output optical fiber 114. The light beam incident on the detection optical fiber 116 passes through the detection optical fiber 116 and reaches the PD 172. The PD 172 outputs a signal reflecting the amount of incident light beam.

  The plurality of movable mirrors 140 are arranged in a line in an array. Thus, a suitable example of the movable mirrors arranged in a line in an array is a MEMS mirror manufactured using a micro electro mechanical system (MEMS) technique. FIG. 2 is a perspective view of the movable mirror 140 shown in FIG. 1 constituted by a MEMS mirror.

  As shown in FIG. 2, one movable mirror 140 has one mirror 142. The mirror 142 is connected to two frames 146 extending on both sides along the row of movable mirrors 140 via two hinges 144 extending in a straight line. The hinge 144 can be twisted and deformed relatively easily, and the mirror 142 can change its direction within a predetermined angle range with the hinge 144 as an axis.

  One GND electrode 148 is provided on the back surface of the mirror 142. The movable mirror 140 further has two drive electrodes 152 facing the GND electrode 148 of the mirror 142. The drive electrode 152 is provided on the electrode substrate 154 disposed on the back side of the mirror 142.

  In such a movable mirror 140, the direction of the mirror 142 is changed by an electrostatic force generated by applying a voltage between the GND electrode 148 and the drive electrode 152. The movable mirror 140 deflects the light beam reflected by the mirror 142 in accordance with the direction of the mirror 142.

  Thus, although the movable mirror 140 is driven by electrostatic attraction, it is known that the driving characteristics of electrostatic driving change due to environmental changes, and a predetermined deflection angle is maintained even when the same driving voltage is applied. It may not be obtained.

  Here, assuming that the drive sensitivity of the movable mirror 140 has changed, a method for calibrating the angle control error due to this change in drive sensitivity will be described.

  FIG. 3 is a graph of the mirror deflection angle with respect to the drive voltage before and after the drive sensitivity of the movable mirror 140 is changed. In FIG. 3, the drive characteristic 191 of the movable mirror 140 before the drive sensitivity changes is the swing angle 193 of the movable mirror 140 necessary for directing the light beam to the detection optical fiber 116 at the drive voltage value 194. On the other hand, in the drive characteristic 192 of the movable mirror 140 after the drive sensitivity is changed, the swing angle 193 of the movable mirror 140 necessary for directing the light beam to the detection optical fiber 116 is obtained at the drive voltage value 195.

  As is apparent from FIG. 3, when the drive characteristic of the movable mirror 140 changes, the drive voltage value needs to be calibrated in order to direct the light beam to the optical fiber 116 for detection. Similarly, the drive voltage value necessary for directing the light beam to the output optical fiber 114 needs to be calibrated.

  FIG. 4 is a flowchart of the drive voltage value calibration operation in the first embodiment.

  Next, the operation for calibrating the drive voltage value when the drive sensitivity changes in the present embodiment will be described with reference to FIGS. 3 and 4.

  First, step S101 for selecting the movable mirror 140 for which the drive voltage value is calibrated is performed.

  Next, step S102 is performed in which a drive voltage value necessary for the light beam deflected by the movable mirror 140 to be calibrated to go to the detection optical fiber 116 is read from the memory 176 and written to the adjustment circuit 178.

  Next, step S103 is performed in which the drive voltage value read in step S102 is output to the mirror drive circuit 180 to change the deflection angle of the movable mirror 140. By performing step S103, the light beam deflected by the movable mirror 140 is coupled to the optical fiber 116 for detection, and the amount of light can be detected by the PD 172.

  Next, step S <b> 104 is performed in which the adjustment circuit 178 adjusts the drive voltage value so as to maximize the output of the PD 172 and repeats the operation of outputting to the mirror drive circuit 180. By performing step S104, a drive voltage value necessary for the most efficient coupling of the light beam deflected by the movable mirror 140 and the detection optical fiber 116 is obtained.

  Next, a straight line of the drive characteristic 192 is interpolated so as to pass the coordinates of the mirror deflection angle and the origin coordinate with respect to the drive voltage value obtained in step S104, and the light is deflected by the movable mirror 140 based on the interpolated drive characteristic 192. Step S105 is performed in which a plurality of drive voltage values necessary for directing the obtained light beam to the plurality of output optical fibers 114 are newly obtained. By performing step S105, it is possible to obtain a drive voltage value reflecting the influence of the change in drive sensitivity of the movable mirror 140.

  Finally, step S106 is performed in which the contents of the memory 176 are overwritten with the drive voltage value obtained in step S105. By carrying out this process, it is possible to drive the movable mirror 140 at a drive voltage value that takes into account the change in drive sensitivity when the movable mirror 140 is driven from the next time.

  By appropriately repeating these steps S101 to S106, the angle control error of the movable mirror 140 can be suppressed, and a stable optical switch device that suppresses an increase in optical loss can be realized.

  In the present embodiment, the drive characteristic of the movable mirror 140 is treated as a straight line. However, when the drive characteristic of the movable mirror 140 is a curve such as a quadratic function, the mirror shake with respect to the drive voltage value obtained in step S104. Calibration can be performed in the same manner by obtaining an approximate curve that passes through the corner coordinates and the origin coordinates, and newly obtaining a drive voltage value necessary for directing the output optical fiber 114 from the obtained approximate curve.

  In step S105, the drive voltage value read in step S102 is compared with the drive voltage value obtained in step S104, and the ratio of the drive voltage value after adjustment to the drive voltage value before adjustment is obtained. Thus, a drive voltage value necessary for directing the deflected light beam to the output optical fiber 114 may be newly obtained.

  In the present embodiment, the movable mirror is an electrostatic drive type MEMS mirror and the drive voltage value is a control value. However, the movable mirror is an electromagnetic drive type MEMS mirror and the drive current value is a control value. Calibration may be performed as follows.

  Next, a modification of the first embodiment will be described in which the drive voltage value is calibrated when an offset occurs in the drive characteristics. When an offset occurs, the drive voltage value required to direct the light beam deflected by the movable mirror 140 to either the output optical fiber 114 or the detection optical fiber 116 increases or decreases equally. Therefore, if an increase / decrease of the drive voltage value necessary for directing the light beam to the detection optical fiber 116 can be obtained, the drive voltage value necessary for directing the light beam to the output optical fiber 114 is equally increased / decreased, The drive voltage value can be calibrated in consideration of the influence of the offset.

  In this modification, the difference between the drive voltage value before adjustment and the drive voltage value after adjustment is obtained in step S104, and the obtained difference is added to the drive voltage value necessary for directing the deflected light beam to the output optical fiber 114. Alternatively, the drive voltage value can be calibrated in consideration of the effect of offset by subtracting.

Second Embodiment The present embodiment is directed to another optical switch device that can switch a wavelength-multiplexed light beam for each wavelength. FIG. 5 shows the configuration of the optical switch device according to the second embodiment of the present invention. In FIG. 5, members indicated by the same reference numerals as those shown in FIG. 1 are similar members, and detailed description thereof is omitted.

  As shown in FIG. 5, the optical switch device 200 of this embodiment includes a memory 276 and an adjustment circuit 278 instead of the memory 176 and the adjustment circuit 178 in FIG. A converging lens 226 and a PD 272 are provided.

  The converging lens 226 converts the parallel light beam from the convex lens 132 directed to the detection optical fiber 216 into a converging light beam. The PD 272 is optically coupled to the detection optical fiber 216. The light quantity of the light beam coupled to the detection optical fiber 216 is detected by the PD 272.

  The detection optical fiber 216, the converging lens 226, and the PD 272 together with the detection optical fiber 116, the converging lens 126, and the PD 172 constitute a light amount detection unit that detects the light amount of the light beam.

  FIG. 6 is a graph showing the mirror deflection angle with respect to the drive voltage when a change in drive sensitivity and an offset occur simultaneously in the drive characteristics of the movable mirror 140. In FIG. 6, in the drive characteristics 291 before the drive sensitivity change and the offset occur in the movable mirror 140, the swing angle 293 of the movable mirror 140 necessary for directing the light beam to the detection optical fiber 216 is the drive voltage value 298. At the drive voltage value 297, the deflection angle 294 of the movable mirror 140 necessary for directing the light beam toward the detection optical fiber 116 is obtained. On the other hand, in the drive characteristic 292 after the change in the drive sensitivity and the offset are simultaneously generated in the movable mirror 140, the swing of the movable mirror 140 necessary for directing the light beam to the detection optical fiber 216 at the drive voltage value 296 is obtained. The angle 293 becomes a swing angle 294 of the movable mirror 140 necessary for directing the light beam to the detection optical fiber 116 at the drive voltage value 295.

  FIG. 7 is a flowchart of the operation for calibrating the drive voltage value in the second embodiment of the present invention.

  In step S201 to step S204, the drive voltage value for directing the light beam toward the detection optical fiber 116 is adjusted. This adjustment is exactly the same as step S101 to step S104 of the first embodiment. In steps S205 to S207, the drive voltage value for directing the light beam toward the detection optical fiber 216 is adjusted. This adjustment is performed in the same manner as in steps S101 to S104 of the first embodiment.

  In step S208, a straight line of the drive characteristic 292 is interpolated so as to pass through the coordinates of the mirror deflection angle with respect to the drive voltage value 295 obtained in step S204 and the coordinates of the mirror deflection angle with respect to the drive voltage value 296 obtained in step S207. . Further, based on the interpolated drive characteristic 292, a plurality of drive voltage values necessary for directing the light beam deflected by the movable mirror 140 to the plurality of output optical fibers 114 are newly obtained.

  In step S209, the drive voltage value stored in the memory 276 is updated with the newly obtained drive voltage value.

  Thus, in this embodiment, the light quantity of the light beam at two different points is detected, and the drive voltage value is adjusted based on the two detected light quantity values. As a result, not only the change in drive sensitivity but also the drive voltage value including the influence of offset can be calibrated.

  In this embodiment, two optical fibers for detection are arranged side by side, but an optical fiber for output may be arranged between the optical fibers for detection.

Third Embodiment This embodiment is directed to another optical switch device that can switch a wavelength-multiplexed light beam for each wavelength. FIG. 8 shows the configuration of the optical switch device according to the third embodiment of the present invention. In FIG. 8, members indicated by the same reference numerals as those shown in FIG. 1 are similar members, and detailed description thereof is omitted.

  As shown in FIG. 8, the optical switch device 300 of this embodiment has a memory 376, an adjustment circuit 378, and an angle control circuit 380 instead of the memory 176, the adjustment circuit 178, and the mirror drive circuit 180 in FIG. doing. The optical switch device 300 further includes a plurality of angle sensors 340 that respectively detect the angles of the plurality of movable mirrors 140.

  The memory 376 stores an angle target value and an angle correction value (control value) of the movable mirror 140 necessary for deflecting the light beam in a predetermined direction. The angle target value is a value determined by the combination of the movable mirror 140, the output optical fiber 114, and the detection optical fiber 116. The angle correction value corrects the output of the angle sensor 340 in feedback control of the swing angle of the movable mirror 140. It is a variable value used to

  In the present embodiment, the control value related to the attitude control of the movable mirror 140 is an angle correction value. The adjustment circuit 378 can read and write the angle correction value stored in the memory 376 and can adjust the angle correction value given to the angle control circuit 380 based on the output of the PD 172.

  The angle control circuit 380 performs feedback control of the deflection angle of the movable mirror 140 based on the angle target value and the angle correction value given from the adjustment circuit 378 and the output of the angle sensor 340.

  FIG. 9 shows the configuration of the angle control circuit 380 shown in FIG. As shown in FIG. 9, the angle control circuit 380 includes an adder 382 that adds an angle correction value to the output of the angle sensor 340 to obtain an angle feedback value, and a subtraction for subtracting the angle feedback value from the angle target value. 384, a phase compensation circuit 386 for stably performing the angle feedback control, and a driver 388 for driving the movable mirror 140.

  The angle control circuit 380 first subtracts the angle feedback value from the angle target value to obtain an error with respect to the angle target value of the deflection angle of the movable mirror 140, and then amplifies the obtained error by the phase compensation circuit 386 and the driver 388. As a result, a drive voltage value that reduces the error of the deflection angle of the movable mirror 140 is output. By repeating this operation, feedback control is performed so that the error between the swing angle of the movable mirror 140 and the target angle value is always minimized.

  By performing feedback control of the swing angle of the movable mirror 140 in this way, the swing angle can be changed so that the target angle value is obtained regardless of the drive characteristics of the movable mirror 140. However, the angle sensor 340 may have a change in detection characteristics such as a change in detection sensitivity or an offset due to environmental factors over time. When the detection characteristic changes, the output of the angle sensor 340 includes an error, and this error appears as an angle control error in feedback control. Here, an operation is described in which an angle correction value is added to the output so that a change in detection sensitivity of the angle sensor 340 can be corrected, and the effect of a change in detection sensitivity of the angle sensor 340 is calibrated using this angle correction value as a control value. To do.

  FIG. 10 is a flowchart of the calibration operation due to the influence of the change in detection sensitivity of the angle sensor in the third embodiment. Next, an operation for calibrating the influence of a change in detection sensitivity of the angle sensor 340 in the third embodiment of the present invention will be described with reference to FIG.

  First, step S301 is performed in which the movable mirror 140 that performs calibration of the angle correction value is selected.

  Next, step S302 is performed in which the target angle value and the angle correction value of the movable mirror 140 are read from the memory 376 and read into the adjustment circuit 378 so that the light beam deflected by the movable mirror 140 is directed to the detection optical fiber 116. .

  Next, the angle target value and the angle correction value read in step S302 are output to the angle control circuit 380, and step S303 is performed in which the deflection angle of the movable mirror 140 is changed. By performing step S303, the light beam deflected by the movable mirror 140 is coupled to the detection optical fiber 116, and the light quantity can be detected by the PD 172.

  Next, step S304 is performed in which the operation of adjusting the angle correction value by the adjustment circuit 378 and outputting the result to the angle control circuit 380 is repeated so that the output of the PD 172 becomes maximum. By performing step S304, an angle correction value necessary for the most efficient coupling of the light beam deflected by the movable mirror 140 and the detection optical fiber 116 is obtained.

  Next, a straight line for interpolating the angle correction value so as to pass through the coordinates and the origin of the mirror deflection angle with respect to the angle correction value obtained in step S304 is obtained, and the light beam is directed to the output optical fiber 114 based on the obtained straight line. In step S305, an angle correction value necessary for deflecting the light beam is obtained. By performing step S305, an angle correction value reflecting the influence of the change in detection sensitivity of the angle sensor 340 can be obtained.

  Finally, step S306 is performed in which the contents of the memory 376 are overwritten with the angle correction value obtained in step S305. By performing step S306, the output of the angle sensor 340 is corrected with an angle correction value that takes into account the change in the detection sensitivity of the angle sensor 340 when performing the feedback control of the swing angle of the movable mirror 140 from the next time. Is possible.

  By appropriately repeating these steps S301 to S306, an angle control error in the angle feedback control of the movable mirror 140 can be suppressed, and a stable optical switch device that suppresses an increase in optical loss is realized. Can do.

  The angle correction value read in step S302 is compared with the angle correction value obtained in step S304, and the ratio of the angle correction value after adjustment to the angle correction value before adjustment is obtained, so that the obtained ratio is obtained. The angle correction value necessary to deflect the light beam so that the light beam is directed to the output optical fiber 114 may be obtained.

  In the present embodiment, as shown in the first embodiment, even if the difference between the angle correction value before adjustment and the angle correction value after adjustment is obtained and the angle correction value is calibrated when an offset occurs, Good. Similarly to the second embodiment, two PDs may be provided, and angle correction values may be calibrated from the outputs of the two PDs.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to these embodiments, and various modifications and changes can be made without departing from the scope of the present invention. Also good.

Summary The present invention is directed, in part, to optical switch devices and includes the optical switch devices listed in the following sections.

  1. The optical switch device of the present invention includes at least one input optical fiber, at least one output optical fiber, a movable mirror for directing a light beam from the input optical fiber to the output optical fiber, and attitude control of the movable mirror. Control information holding means for holding a control value, a drive means for driving the movable mirror based on the control value, a light quantity detection means for detecting the light quantity of the light beam, and a control value based on the output of the light quantity detection means Adjusting means for obtaining a control value necessary for directing the light beam to the output optical fiber based on the adjusted control value, and updating the control value held in the control information holding means with the obtained control value And.

  In this optical switch device, it is possible to suppress the angle control error by adjusting the control value based on the output of the light quantity detection means, for example, so that the output of the light quantity detection means is maximized. By calibrating the control value required to direct the light beam to the output optical fiber based on the adjusted control value, the angle control error can be suppressed, and the increase in light loss can be suppressed. Therefore, an optical switch device having stable characteristics can be provided.

  2. In another optical switch device of the present invention, in the optical switch device according to the first term, the control value is a drive electric signal for driving the movable mirror.

  Since this optical switch device calibrates the value of the drive electrical signal necessary to control the swing angle of the movable mirror, it is possible to realize calibration with a minimum of addition of a control circuit. An increase in optical loss can be suppressed at a cost.

  3. Another optical switch device according to the present invention is the optical switch device according to item 2, wherein the light amount detecting means is optically coupled to one optical fiber for detection provided in the same row as the optical fiber for output, and the optical fiber for detection. And a single photodetector.

  In this optical switch device, the optical fiber for detection is arranged in the same row as the optical fiber for output along the deflection direction of the optical beam by the movable mirror, so the optical beam is detected by changing the deflection angle of the movable mirror. It is possible to lead to the vessel stably. Since the light quantity is detected via the optical fiber, it is possible to adjust the control value based on the light quantity, for example, to adjust the control value that maximizes the light quantity with high accuracy. As a result, the accuracy of calibration is increased and an increase in light loss can be further suppressed.

  4). Another optical switch device of the present invention is the optical switch device according to the third item, wherein the adjusting means passes through the coordinates of the deflection angle of the movable mirror with respect to the drive electric signal and the origin coordinate and corresponds to the drive characteristic of the movable mirror. A curve (the curve also includes a straight line) is obtained, and a drive electric signal value necessary for directing the light beam to the output optical fiber is obtained based on the obtained approximate curve.

  In this optical switch device, the drive voltage value can be calibrated in consideration of the influence of the sensitivity change of the drive characteristics of the movable mirror.

  5). Another optical switch device according to the present invention is the optical switch device according to the third item, wherein the adjustment means obtains a difference between the drive electric signal before adjustment and the drive electric signal after adjustment, and uses the obtained difference in the output optical fiber. Addition / subtraction to the drive electric signal value necessary for directing the light beam.

  In this optical switch device, the drive voltage value can be calibrated in consideration of the offset effect of the drive characteristics of the movable mirror.

  6). Another optical switch device according to the present invention is the optical switch device according to item 2, wherein the light amount detecting means is optically provided for the plurality of detection optical fibers provided in the same row as the output optical fiber and the plurality of detection optical fibers. And a plurality of photodetectors coupled to each other.

  In this optical switch device, the optical fiber for detection is arranged in the same row as the optical fiber for output along the deflection direction of the optical beam by the movable mirror, so the optical beam is detected by changing the deflection angle of the movable mirror. It is possible to lead to the vessel stably. By adjusting the control values based on the outputs of the plurality of photodetectors, a plurality of adjusted control values can be obtained. By performing calibration based on the obtained plurality of control values, the accuracy of calibration is increased, and an increase in light loss can be further suppressed.

  7). Another optical switch device according to the present invention is the optical switch device according to item 6, wherein the adjusting means passes through a plurality of coordinates of a swing angle of the movable mirror with respect to a plurality of drive electric signals and corresponds to the drive characteristic of the movable mirror. A curve (here, the curve also includes a straight line) is obtained, and based on the obtained approximate curve, a drive electric signal necessary for directing the light beam to the output optical fiber is obtained.

  In this optical switch device, the drive voltage value can be calibrated in consideration of the sensitivity change of the drive characteristics of the movable mirror and the influence of the offset.

  8). Another optical switch device according to the present invention is the optical switch device according to the first item, in which an angle detector that detects a deflection angle of the movable mirror, an adder that adds a correction value to the output of the angle detector, Control means for controlling the movable mirror so that the output becomes a predetermined angle target value, and the control value is a correction value added to the output of the angle detection means.

  In this optical switch device, the swing angle of the movable mirror is detected and feedback-controlled, and calibration is performed for the correction value for correcting the output of the angle sensor. As a result, an angle control error in feedback control can be suppressed, and an increase in optical loss can be suppressed.

  9. Another optical switch device of the present invention is the optical switch device according to item 8, wherein the light amount detecting means is optically coupled to one optical fiber for detection provided in the same row as the optical fiber for output, and the optical fiber for detection. And a single photodetector.

  In this optical switch device, the optical fiber for detection is arranged in the same row as the optical fiber for output along the deflection direction of the optical beam by the movable mirror, so the optical beam is detected by changing the deflection angle of the movable mirror. It is possible to lead to the vessel stably. Since the light quantity is detected via the optical fiber, it is possible to adjust the control value based on the light quantity, for example, to adjust the control value that maximizes the light quantity with high accuracy. As a result, the accuracy of calibration is increased and an increase in light loss can be further suppressed.

  10. The calibration method of the present invention includes a step of detecting a light amount of a light beam from an input optical fiber, a step of adjusting a control value of the movable mirror based on the detected light amount, and a light based on the adjusted control value. A step of obtaining a control value for controlling the movable mirror so as to direct the beam toward the output optical fiber, and a step of updating the control value held in the control information holding means with the obtained control value.

  In this calibration method, the angle control error can be suppressed by adjusting the control value based on the light amount of the light beam from the input optical fiber, for example, so as to maximize the light amount of the light beam from the input optical fiber. It becomes possible. By calibrating the control value necessary to direct the light beam to the output optical fiber based on the adjusted control value, the angle control error can be suppressed, and the increase in light loss can be suppressed. Therefore, an optical switch device having stable characteristics can be provided.

  11. According to another calibration method of the present invention, in the calibration method according to item 10, the step of detecting the light amount of the light beam includes detecting the light amount of the light beam at a plurality of positions and adjusting the control value. The control value is adjusted based on the light amount of the light beam at the position, and the control value held in the control information holding means is updated based on the adjusted plurality of control values.

  In this calibration method, the control value is adjusted based on the light amount of the light beam at a plurality of positions, so that a plurality of adjusted control values can be acquired. Since calibration can be performed based on the obtained plurality of control values, the accuracy of calibration is increased, and an increase in light loss can be further suppressed.

The structure of the optical switch apparatus of 1st embodiment of this invention is shown. It is a perspective view of the movable mirror shown by FIG. 1 comprised with the MEMS mirror. It is a graph of the mirror deflection angle with respect to the drive voltage before and after the drive sensitivity of the movable mirror changes in the optical switch device. It is a flowchart of the calibration operation | movement of the drive voltage value in 1st embodiment. The structure of the optical switch apparatus of 2nd embodiment of this invention is shown. 6 is a graph showing a mirror deflection angle with respect to a drive voltage when a change in drive sensitivity and an offset occur simultaneously in the drive characteristics of a movable mirror in an optical switch device. It is a flowchart of the operation | movement which calibrates the drive voltage value in 2nd embodiment of this invention. The structure of the optical switch apparatus of 3rd embodiment of this invention is shown. 9 shows a configuration of the angle control circuit shown in FIG. It is a flowchart of the calibration operation | movement by the influence of the change of the detection sensitivity of the angle sensor in 3rd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Optical switch apparatus, 112 ... Input optical fiber, 114 ... Output optical fiber, 116 ... Detection optical fiber, 122 ... Collimating lens, 124 ... Converging lens, 126 ... Converging lens, 132 ... Convex lens, 134 ... Convex lens, 136 ... Grating , 140 ... movable mirror, 142 ... mirror, 144 ... hinge, 146 ... frame, 148 ... GND electrode, 152 ... drive electrode, 154 ... electrode substrate, 172 ... PD, 176 ... memory, 178 ... adjustment circuit, 180 ... mirror drive Circuit: 200 ... Optical switch device, 216: Optical fiber for detection, 226 ... Converging lens, 272 ... PD, 276 ... Memory, 278 ... Adjustment circuit, 300 ... Optical switch device, 340 ... Angle sensor, 376 ... Memory, 378 ... Adjustment Circuit, 380... Angle control circuit, 382 Adder, 384 ... subtractor, 386 ... phase compensating circuit, 388 ... driver.

Claims (11)

At least one input optical fiber;
At least one optical fiber for output;
A movable mirror for directing the light beam from the input optical fiber to the output optical fiber;
Control information holding means for holding control values related to the attitude control of the movable mirror;
Driving means for driving the movable mirror based on the control value;
A light amount detecting means for detecting the light amount of the light beam;
The control value is adjusted based on the output of the light quantity detection means, the control value necessary for directing the light beam to the output optical fiber is obtained based on the adjusted control value, and the obtained control value is held in the control information holding means And an adjusting means for updating the control value.   2. The optical switch device according to claim 1, wherein the control value is a drive electric signal for driving the movable mirror.   In claim 2, the light amount detection means includes a single detection optical fiber provided in the same row as the output optical fiber, and a single photodetector optically coupled to the detection optical fiber. Optical switch device.   4. The adjustment unit according to claim 3, wherein the adjusting means obtains an approximate curve (where the curve includes a straight line) corresponding to the drive characteristics of the movable mirror, which passes through the coordinates of the deflection angle of the movable mirror and the origin coordinates with respect to the drive electrical signal. An optical switch device for obtaining a drive electric signal value necessary for directing the light beam to the output optical fiber based on the approximate curve.   4. The adjustment means according to claim 3, wherein the adjustment means obtains a difference between the drive electric signal before adjustment and the drive electric signal after adjustment, and adds or subtracts the obtained difference to a drive electric signal value necessary for directing the light beam to the output optical fiber. An optical switch device.   The light quantity detecting means according to claim 2, wherein the light amount detecting means includes a plurality of detection optical fibers provided in the same row as the output optical fiber, and a plurality of photodetectors optically coupled to the plurality of detection optical fibers. An optical switch device.   7. The adjustment means according to claim 6, wherein the adjusting means obtains an approximate curve (the curve includes a straight line) corresponding to the drive characteristic of the movable mirror, which passes through the plurality of coordinates of the swing angle of the movable mirror with respect to the plurality of drive electrical signals. An optical switch device for obtaining a drive electric signal necessary for directing a light beam to an output optical fiber based on the approximate curve.   2. The angle detection means for detecting a deflection angle of the movable mirror, an adder for adding a correction value to the output of the angle detection means, and the movable mirror so that the output of the adder becomes a predetermined angle target value. An optical switch device having a control means for controlling, wherein the control value is a correction value added to the output of the angle detection means.   In claim 8, the light amount detection means includes a single detection optical fiber provided in the same row as the output optical fiber, and a single photodetector optically coupled to the detection optical fiber. Optical switch device. At least one input optical fiber, at least one output optical fiber, a movable mirror for directing the light beam from the input optical fiber to the output optical fiber, and control information holding the control value of the movable mirror And a method for calibrating an optical switch device comprising a driving means for driving a movable mirror based on a control value,
Detecting the amount of light beam from the input optical fiber;
Adjusting the control value of the movable mirror based on the detected light amount;
A step of obtaining a control value for controlling the movable mirror so that the light beam is directed to the output optical fiber based on the adjusted control value, and the control value held in the control information holding means is updated with the obtained control value. And a calibration method.   The step of detecting the light amount of the light beam according to claim 10 includes detecting the light amount of the light beam at a plurality of positions and adjusting the control value based on the light amount of the light beam at the plurality of positions. A calibration method for adjusting and updating a control value held in a control information holding unit based on a plurality of adjusted control values.

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