JP2004239649A - Apparatus and method for testing optical switch and light signal exchanging apparatus and its controlling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently test an optical switch for shortening test time and to reduce the amount of data regarding the test result of the optical switch for decreasing capacity for storage. <P>SOLUTION: A light source 2 supplies a light signal to the optical switch 100. In the output of the optical switch 100, a light reception level is detected by a photodetector 3. A control unit 4 changes the amount of control in deflection for changing the angle of a tilt mirror of the optical switch 100 for outputting to a drive section 6. When an input port is the same as an output one, the optical offset of the tilt mirror is calculated, based on an angle, where the photodetector 3 detects an optimum point in the reception level. Contrarily, each time when the input port differs from the output one, the structure parameter of the tilt mirror is calculated, based on the calculated optical offset and the angle, where the photodetector 3 detects the optimum point at the reception level. The optical offset and the structure parameter are stored into a memory 5 as a test result. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical switch test apparatus provided with a MEMS mirror array, and more particularly to an optical switch test apparatus and an optical switch test method capable of efficiently and accurately obtaining a deflection control amount. In addition, the present invention relates to an optical signal switching device having the optical switch and capable of stabilizing an optical output, and a control method of the optical signal switching device. By using such an optical switch, an optical path can be switched in an optical cross-connect system using a WDM signal.
[0002]
[Prior art]
Recently, with the rapid spread of the Internet, traffic has increased dramatically. As a method for constructing a large-capacity optical communication network in response to an increase in traffic, there is a wavelength division multiplexing (WDM) method. There is an optical cross-connect (OXC) system as a basic optical network based on the WDM system. This optical cross-connect system has a configuration in which a plurality of optical signal switching devices are mutually connected on an optical transmission line composed of optical fibers.
[0003]
An optical signal (WDM signal) that has been wavelength-multiplexed through an optical fiber is input to the optical signal switching apparatus, and an optical signal on the same optical transmission line is wavelength-multiplexed and transmitted. This optical signal switching device is provided with an optical switch therein, and the optical switch can switch an optical path of an optical signal to another optical path in wavelength units and output the optical signal to another optical transmission path.
[0004]
As described above, according to the optical cross-connect system using the optical signal switching device, when a failure occurs in an optical fiber constituting a certain optical transmission line, the optical path is immediately switched by an internal optical switch to make a backup. The optical signal can be bypassed to an optical fiber constituting another optical transmission line such as an optical transmission line or an optical fiber of another route. Therefore, even if a failure occurs in the optical transmission line, it can be restored at a high speed, and the optical path can be switched (edited) in wavelength units.
[0005]
FIG. 13 is a perspective view showing an optical switch. The illustrated optical switch is an optical switch 100 of a three-dimensional MEMS, and includes two MEMS mirror arrays 101 and 102 manufactured by applying a bulk micro electric mechanical system technology, and these two MEMS mirror arrays 101. , 102 are provided with two collimator arrays 103, 104 for inputting and outputting light. The MEMS mirror arrays 101 and 102 formed by the bulk micromachine technology form a support or a mirror forming portion into a desired shape by etching a material substrate itself, and form a thin film on a mirror surface or an electrode as necessary. Become. By using the MEMS mirror arrays 101 and 102, an optical switch that spatially switches an optical path can be configured.
[0006]
Each of the MEMS mirror arrays 101 and 102 includes a plurality of tilt mirrors 105 and 106 in a matrix. The tilt mirrors 105 and 106 can be independently changed in angle in two axes (X-axis and Y-axis). By changing the exit angle of the incident light A, the optical path of the light A can be switched to an arbitrary angle. I can do it. The collimator arrays 103 and 104 have a number of input / output ports corresponding to the plurality of tilt mirrors 105 and 106 of the MEMS mirror arrays 101 and 102 formed in a matrix.
[0007]
The technology relating to such a three-dimensional MEMS optical switch is disclosed, for example, in Non-Patent Document 1 below. Further, a technique related to a MEMS mirror having a comb-shaped electrode capable of changing the angle of each mirror in two axial directions (X axis and Y axis) is disclosed in, for example, Patent Document 1 below.
[0008]
An optical switch using such MEMS mirror arrays 101 and 102 has an advantage over other switches in terms of miniaturization, wavelength independence, polarization independence, and the like, and is attracting attention. The optical signal switching device using the three-dimensional MEMS optical switch 100 as described above can realize reduction of optical loss, increase in capacity, and increase in number of channels.
[0009]
In the optical switch 100, the ends of the optical fibers (not shown) of a plurality of ports (103-1 to 103-N, 104-1 to 104-N) are arranged in the collimator arrays 103 and 104, respectively. In the illustrated example, both the collimator array 103 on the input side and the collimator array 104 on the output side are arranged in parallel such that the light input direction faces forward in the drawing and the light output direction faces backward.
[0010]
These collimator arrays 103 and 104 have a plurality of ports (103-1 to 103-N, 104-1 to 104-N) in a matrix in the vertical and horizontal directions, respectively. To each port, an end of an optical fiber (not shown) is fixedly arranged for inputting / outputting an optical signal. Each port of the collimator arrays 103 and 104 has a rear surface subjected to end face processing for emitting light from an optical fiber.
[0011]
MEMS mirror arrays 101 and 102 are arranged behind the collimator arrays 103 and 104 in correspondence with the arrangement intervals of the collimator arrays 103 and 104. The MEMS mirror arrays 101 and 102 are arranged so as to be inclined by 45 ° with respect to the direction of the optical path A between the MEMS mirror arrays 101 and 104, respectively. Further, the collimator array 103 and the collimator array 104 are arranged at an angle of 90 ° orthogonal to each other. As a result, as shown in the figure, the light input to each port of the collimator array 103 on the input side is emitted as the optical path A, and is reflected by the MEMS mirror array 101 on the input side toward the MEMS mirror array 102 on the output side. . The MEMS mirror array 102 can reflect light toward the collimator array 104 and output the light from each port of the collimator array 104.
[0012]
The tilt mirror 105 of the MEMS mirror array 101 will be described as an input mirror, and the tilt mirror 106 of the MEMS mirror array 102 will be described as an output mirror. Each of the input mirror 105 and the output mirror 106 includes a deflecting unit (not shown) having the above-described comb-shaped electrode. By supplying a deflection control amount (drive voltage) corresponding to the angle change to the deflecting means, the angles of the input mirror 105 and the output mirror 106 are continuously varied according to the value of the drive voltage.
[0013]
At the time of a through pass, the light A output from the port 3 (103-3) of the collimator array 103 is reflected by the input mirror 105-3 of the MEMS mirror array 101 and then reflected by the output mirror 106-3 of the MEMS mirror array 102. Then, the light enters the port 3 (104-3) of the collimator array 104. At this time, the surfaces of the input mirror 105-3 and the output mirror 106-3 of the MEMS mirror arrays 101 and 102 are in a state parallel to the surface of the main body of the MEMS mirror arrays 101 and 102. In this state, the control of the angle change with respect to the input mirror 105-3 and the output mirror 106-3 is not performed.
[0014]
At the time of the cross pass, by controlling the angle change of the input mirror 105-3 of the MEMS mirror array 101 and the output mirror 106-3 of the MEMS mirror array 102, the light of the port 3 (103-3) of the collimator array 103 is controlled. The reflection direction of the light incident on A is changed (referred to as deflection), and the light is incident on an arbitrary port (any of 104-1 to 104 -N) of the collimator array 104. In this way, the optical switch 100 can switch light input from a plurality of ports to an arbitrary port and output the light. The optical signal switching device described later switches (hereinafter, referred to as switching) the optical signals of a plurality of systems on the optical transmission line to different systems by this port switching.
[0015]
By the way, in the optical switch 100, the optical path (the optical axis of the light A) is shifted and enters the output side optical fiber connected to the output side collimator array 104 in both the through path and the cross path. There is. The deviation of the optical path occurs due to the structural characteristics of the MEMS mirror arrays 101 and 102, the angular deviation of the mirror actually moved with respect to the control amount at the time of changing the angle, the deviation of the arrangement of members at the time of assembly, and the like. The deviation of the optical path causes an increase in the optical loss of the optical signal switching device including the optical switch 100. A control technique for reducing the optical loss of an optical signal in such an optical switch is disclosed in, for example, Patent Literature 2 and Patent Literature 3 below.
[0016]
FIG. 14 is a flowchart showing a test procedure for obtaining a deflection control amount of an optical switch according to the related art. This test is performed on the assumption that there is no deviation in the arrangement of members when the optical switch 100 is assembled. In the following description, for convenience, the collimator array 103 side is a light input side, the collimator array 104 is a light output side, the tilt mirror 105 of the MEMS mirror array 101 is an input mirror, and the tilt mirror 106 of the MEMS mirror array 102 is a This will be described as an output mirror.
[0017]
First, in setting an input / output port, an input port having the collimator array 103 and an output port of the collimator array 104 are set (step S101). Next, when light is input from the input port set on the collimator array 103 side, a deflection angle for outputting light from the output port set on the collimator array 104 side is calculated (step S102). This deflection angle is calculated based on a theoretical value required for changing the angles of the input mirror 105 and the output mirror 106 of the MEMS mirror arrays 101 and 102.
[0018]
Next, using the calculated deflection angles, the input mirror 105 of the MEMS mirror array 101 and the deflection means (not shown) of the output mirror 106 of the MEMS mirror array 102 are controlled to change the angle. Specifically, the deflecting unit is driven (Step S103), and the angles of the two axes (X axis and Y axis) of the input mirror 105 and the output mirror 106 are continuously changed. At the same time, the light receiving level of the light A output from the output port of the collimator array 104 is detected by a photodetector (not shown) (step S104), and the optimum point of the optical loss is obtained (step S105).
[0019]
Until the optimum point is obtained (step S105: No), the driving of the deflecting unit in step S103 and the detection of the light receiving level in step S104 are continued by the feedback control. When the optimum point is obtained (Step S105: Yes), an angular position corresponding to the optimum point is obtained as a deflection control amount. The optimum point is the angle position when the light loss between the set input / output ports is minimum, that is, when the light reception level is detected to be the highest.
[0020]
Through the above processing, the deflection control amounts at one input / output port set at step S101, that is, at one input port of the collimator array 103 and at the output port of the collimator array 104 are obtained. Then, the above processing is performed by setting a new combination of input / output ports (Step S106: No). When the optimum points for all the ports of the matrix-like collimator arrays 103 and 104 are obtained (step S106: Yes), the deflection control amounts of the combination of all the input / output ports by the above-mentioned through path and cross path can be obtained.
[0021]
[Patent Document 1]
JP 2002-328316 A
[Patent Document 2]
Japanese Patent Publication No. Hei 9-508218
[Patent Document 3]
JP 2002-236264 A
[Non-patent document 1]
"High-speed switching three-dimensional MEMS optical switch", IEICE Communications Society Conference, 2002, p. 447
[0022]
[Problems to be solved by the invention]
However, according to the above-described related art, when the displacement of the members at the time of assembling the optical switch 100 occurs, the deflection control amount that maximizes the output light receiving level deviates from the theoretical value described above. As a result, there is a problem that the processing until the deflection control amount at which the light receiving level becomes the maximum, that is, the number of feedback controls in steps S103 to S105 increases, and the test time increases.
[0023]
In the above-described test processing, the deflection control amount is calculated using the theoretical values of the MEMS mirror arrays 101 and 102. For this reason, if the variation inherent in each of the input mirror 105 and the output mirror 106 of the MEMS mirror arrays 101 and 102 is large, the deviation of the calculated value of the deflection control amount becomes large, and the test time increases.
[0024]
When the number of input ports and the number of output ports of the optical switch are N, the combination that can be switched by the through path and the cross path is N²It becomes street. In the optical switch 100 illustrated in FIG. 13, the dislocation of members occurs during assembly. Therefore, if the number of the input port is i and the number of the output port is j, even if a through-pass test in which i = j is performed, This means that deflection control needs to be performed. In addition, the misalignment of the members that occurs during the assembly requires execution of the deflection control even in the test of the cross path where i ≠ j. Therefore, according to the conventional test processing, it takes about 5 (minutes) to test a certain path. Therefore, in order to test the deflection control amount of the N × N optical switch, 5 × N is required as a whole.²(Min) test time was required.
[0025]
Incidentally, the above-described optical switch test processing is performed using an optical switch test apparatus. The optical switch test apparatus includes a light source that emits an optical signal to each input port of the optical switch, a photodetector that detects a light receiving level of an optical signal obtained from each output port of the optical switch, and a control that executes the test processing. It is composed of a circuit. The control circuit stores the deflection control amount obtained by the test processing in a memory. Therefore, the deflection control amount obtained as a result of testing the optical switch is stored in the memory as a control parameter unique to each optical switch.
[0026]
The optical signal exchange device incorporating the optical switch reads out the parameters stored in the memory and operates the actual optical signal exchange operation. For example, when receiving the switching instruction, the optical signal switching device reads the deflection control amount corresponding to the set input / output port from the memory and drives the deflection unit.
[0027]
FIG. 15 is a chart showing the contents of the memory for storing the deflection control amount. The contents of the parameters stored in the memory 110 are listed. As described above, the combination of the input port and the output port is N²You need it. In addition, since the X-axis and Y-axis deflection control amounts are required for the input mirror 105 and the output mirror 106 of the MEMS mirror arrays 101 and 102 for one path, the number of mirrors is four. Therefore, in the case of an optical switch having N input ports and N output ports, 4N²It is necessary to store the deflection control amounts. As a result, in the prior art, 4N is stored in the memory 110.²In order to store the deflection control amount for each unit, the memory capacity is increased. In particular, if the size of the optical switch becomes large in the future, such as an increase in the number of input / output ports, the required memory capacity will increase by the square of the number of ports, so that the memory will increase exponentially. Become.
[0028]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is possible to efficiently perform a test of an optical switch, shorten a test time, and reduce a data amount of a test result of the optical switch to reduce a memory capacity for storing the test result. An object of the present invention is to provide an optical switch test apparatus that does not take an optical switch test method. Further, another object of the present invention is to provide an optical signal switching device capable of always performing stable optical switching by reducing optical loss when switching an optical signal in an optical transmission line, and a control method of the optical signal switching device. With the goal.
[0029]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object, an optical switch test apparatus of the present invention has the following features. The optical switch deflects an optical path to switch an optical signal between an input port and an output port corresponding to an arbitrary path. The light source inputs a test optical signal to each input port of the optical switch, and the photodetector detects a light receiving level of the optical signal output from each output port of the optical switch. The calculating means obtains an optimum point at which the light receiving level of the optical signal detected by the photodetector is maximum while changing the deflection state of the optical switch, and sets a parameter for optimizing the deflection state to the optimum point. Calculate based on The optical switch includes a plurality of tilt mirrors corresponding to the number of input / output ports, and first deflecting means for driving the tilt mirrors to reflect an optical signal incident from the input port in an arbitrary angle direction. And a second mirror array having second deflecting means. The control means is configured to change an angle of a tilt mirror each time an optical path of a through path is formed between an input port and an output port of an optical switch, and to adjust an optimum point at which a light receiving level of an optical signal detected by a photodetector is maximized. Is calculated, and an optical offset for optimizing the state of deflection is calculated based on the optimum point and stored in a memory. Thereafter, the control means calculates a structural parameter and stores it in a memory each time an optical path of a cross path is formed. When the optical switch is switched, the optical offset and the structural parameter are read from the memory, the deflection control amount of the corresponding input / output port is calculated, and the calculated deflection control amount is supplied to the first deflection unit and the second deflection unit.
[0030]
According to the present invention, the parameter for optimizing the state of deflection can be obtained by calculation by finding the optimum point at which the light receiving level becomes maximum while changing the state of deflection of the optical switch. For example, it is possible to form an optical path of a through path in a default state in which the tilt mirror does not change the angle, and calculate an optical offset between an input port and an output port corresponding to the through path. Then, the optical path of the cross path is formed using the optical offset, and the structural parameters of the input port and the output port corresponding to the cross path can be calculated. The memory only needs to store the optical offset relating to the same port as the input port and the output port corresponding to the through path, and the structural parameters of the first and second mirror arrays corresponding to the cross path, so that the memory usage can be reduced. .
[0031]
Further, the optical signal exchange device of the present invention has the following features. An optical switch and a memory storing the test result of the optical switch test device are mounted on the optical signal exchange device. During operation for switching an optical signal in an optical transmission line, a photodetector detects a light receiving level of an optical signal output from each output port of the optical switch. The deflection control amount calculation means reads the optical offset and the structural parameters of the tilt mirrors of the first mirror array and the second mirror array from the memory, and changes the angles of the tilt mirrors of the first mirror array and the second mirror array. Is calculated and supplied to the first and second deflecting means. The control means, based on the deflection control amount calculated by the deflection control amount calculation means and the light reception level detected by the photodetector, changes the deflection control amount to a maximum light reception level of the optical signal detected by the photodetector. The control for finding the optimal point is executed.
[0032]
According to the present invention, at the time of the operation of switching the optical signal, the light receiving level of the optical signal output from each output port after the switching can be maximized and the optical loss can be minimized. Can be performed.
[0033]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, an optical switch test apparatus according to the present invention will be described. This optical switch test apparatus tests the optical characteristics of an optical switch. FIG. 1 is a block diagram showing the configuration of the optical switch test device of the present invention. As shown in the figure, the optical switch 100 is designed to be incorporated into the optical switch test apparatus 1 for testing. The optical switch test apparatus 1 includes a light source 2, a photodetector 3, a control unit 4, a memory 5, and a drive unit 6.
[0034]
A test optical signal output from the light source 2 is output to the optical switch 100 via the optical fiber 10. The optical switch 100 switches the optical signal described above and outputs the signal to the photodetector 3 via the optical fiber 11. The optical switch 100 has the number N of ports, and the number of output ports of the optical signal of the light source 2 and the number of input ports of the photodetector 3 have the number N similarly. Correspondingly, the optical fibers 10 and 11 also have the number N.
[0035]
Specifically, one end of each of the N optical fibers 10 is connected to the light source 2, and the other end is connected to each of the ports 103-1 to 103-N of the collimator array 103 on the input side of the optical switch 100. One end of the optical fiber 11 is connected to each of the ports 104-1 to 104-N of the collimator array 104 on the output side of the optical switch 100, and the other end is connected to the photodetector 3. Thus, optical signals can be input from the light source 2 to all ports of the optical switch 100, and optical signals output from all ports of the optical switch 100 can be detected by the photodetector 3.
[0036]
The photodetector 3 includes, for example, a photodiode that detects an electric signal (photocurrent; current signal) corresponding to the level of the optical signal, and a current / voltage converter that converts the detected photocurrent into a voltage signal and outputs the voltage signal. Etc. The value (detection signal) detected by the photodetector 3 is output to the control unit 4.
[0037]
The control unit 4 controls the operation of the entire optical switch test apparatus 1 when testing the optical switch 100. The control unit 4 includes a control unit 4a, an offset calculation unit 4b, a structure parameter calculation unit 4c, and a deflection control amount calculation unit 4d. The control unit 4a performs an operation using the offset operation unit 4b, the structure parameter operation unit 4c, and the deflection control amount operation unit 4d based on the detection signal input from the photodetector 3 when the optical switch 100 is tested. Control execution. The deflection control amount obtained during the execution of the calculation is output to the drive unit 6, and the final test result (deflection control amount) obtained by the execution of the calculation is stored in the memory 5.
[0038]
The memory 5 lists combinations of input ports and output ports for all the ports of the optical switch 100. The deflection control amount obtained by the arithmetic processing of the control unit 5 is stored for each of all the combinations of the input / output ports.
[0039]
Each of the above-described units configuring the control unit 4 can be configured by an ASIC (Application Specific Integrated Circuit) such as an FPGA (Field Programmable Gate Arrays).
[0040]
The drive unit 6 converts the digital deflection control amount output from the control unit 4 into an analog amount, and drives the optical switch 100. Specifically, a drive voltage (V) corresponding to the angle to be changed is output to the input mirror 105 of the MEMS mirror array 101 and the output mirror 106 of the MEMS mirror array 102 included in the optical switch 100.
[0041]
Next, test contents of the optical switch 100 by the optical switch test apparatus 1 of the present invention will be described. The test of the optical switch 100 is roughly divided into three calculation processes. These three are the calculation processing of [1] optical offset, [2] deflection control amount of cross path, and [3] structural parameter. The details of each calculation process will be described below. FIG. 2 is a flowchart illustrating a switch test procedure performed by the optical switch test apparatus. Hereinafter, the test procedure will be described in accordance with the contents shown in FIG.
[0042]
[1] Optical offset calculation processing
When the test of the optical switch 100 is started, all data in the memory 5 shown in FIG. Then, in FIG. 2, an input port number i and an output port number j are set, and a switching instruction of a through path where i = j is issued (step S1). Thus, the control unit 4a accesses the memory 5, obtains port information corresponding to the switching instruction, and outputs the port information to the driving unit 6.
[0043]
FIG. 3 is a chart showing data contents stored in the memory. As shown, the area of the memory 5 includes an optical offset storage area 5a, an input mirror structure parameter storage area 5b, and an output mirror structure parameter storage area 5c. In the optical offset storage area 5a, the input port number i (1 to N) and the output port number j (1 to N) coincide with each other (i = j)._off) Is stored. The input mirror structure parameter (A) of the input port numbers 1 to N of the input mirror 105 of the MEMS mirror array 101 on the input side is stored in the input mirror structure parameter storage area 5b. The output mirror structure parameter (A) of the output port numbers 1 to N of the output mirror 106 of the output side MEMS mirror array 102 is stored in the output mirror structure parameter storage area 5c.
[0044]
In principle, in the MEMS mirror arrays 101 and 102, when the deflection control amount (drive voltage) output to the drive unit 6 is 0 during a through pass, the optical loss in the optical switch 100 is minimized. However, as described above, the optical loss is not actually minimized due to the deviation at the time of assembling the optical switch 100.
[0045]
Therefore, the input mirror 105 corresponding to the input port number i and the output mirror corresponding to the output port number j in the MEMS mirror arrays 101 and 102 constituting the optical switch 100 via the drive unit 6 Driving means (not shown) provided in each of the mirrors 106 is driven to adjust the angle between the input mirror 105 and the output mirror 106 (step S2).
[0046]
FIG. 4 is a chart showing a change state of the optical loss when the angle is changed. The angles of the input mirror 105 and the output mirror 106 are adjusted by changing the drive voltage, which is the deflection control amount, for the deflection means as described above. It is shown that the light reception level of the optical signal detected by the photodetector 3 changes by continuously changing the drive voltage for the deflection means of the input mirror 105 and the output mirror 106. As shown in the figure, the peak P having the highest light receiving level is the optimum point at which the light loss is minimized. Further, the drive voltage is changed by the voltage value α, but the voltage value α can be set arbitrarily.
[0047]
The light receiving level of the optical signal at this time is detected by the photodetector 3 (step S3), and it is determined whether or not the optimum point at which the light receiving level is highest has been obtained (step S4). The determination of the optimum point is performed by executing the feedback control (Step S4: No to Step S2 to Step S3) returning to Step S2 a plurality of times. In one feedback control, the light reception level obtained when the drive voltage for the deflection means is changed by α is detected, and it is determined whether the light reception level has become higher than the previous light reception level.
[0048]
In this feedback control, a limit number M is determined (step S5). Therefore, the feedback control is performed a predetermined number of times during the period until the limit number M is reached (Step S5: Yes). If the number of times of the feedback control is equal to or greater than the limit number M (step S5: No), the angles of the input mirror 105 and the output mirror 106 to be switched are not normally changed, or the corresponding port number i , J are considered abnormal.
[0049]
In this case, the process returns to step S1, and it is determined that the optimum point at the corresponding port number i or j cannot be obtained, and a switching instruction is given to the next combination of ports to be tested. At this time, the optical switch test apparatus 1 may write a predetermined value indicating “untestable” or “unusable” in the corresponding storage area of the memory 5 or list the untestable ports in a list. .
[0050]
Then, when the optimum point is obtained (Step S4: Yes), the deflection control amount changed by the feedback control is converted into an offset angle by the offset calculation means 4b (Step S6), and becomes the target of the switching instruction in the memory 5. It is stored in the optical offset storage area 5a of the input / output port. The calculation of the optical offset by the offset calculating means 4b is based on the following equation (1), and the deflection angle θ of the deflecting means at the time when the optimum point is obtained is defined as the optical offset.
[0051]
θ = AV²  … (1)
Here, θ: deflection angle of the deflection unit, A: structural parameter of the deflection unit, and V: deflection control amount (drive voltage) output by the driving unit.
[0052]
The optical offset is calculated based on the relationship of the above equation (1). At the stage of calculating the optical offset, a representative value is used as the structural parameter A. However, as will be described later, a process of accurately calculating the structure parameter A later and updating the data is added.
[0053]
Then, it is determined whether or not the calculation of the optical offset has been completed for all the combinations of the input ports related to the through path (step S7). If the calculation of the optical offsets for all the through paths has not been completed (step S7: No), the process returns to step S1. When the measurement of all the output ports corresponding to the through paths is completed (step S7: Yes), the calculation of the optical offset for all the combinations of the port numbers i and j ends.
[0054]
[2] Cross-path deflection control amount calculation processing
After the calculation of the optical offset for all through paths where i = j as the input port number i and the output port number j is completed, the deflection control amount of the cross path is calculated. In the cross path, the switching instruction of the cross path in which the switching instruction is i ≠ j is issued (step S8). Thus, the control unit 4a accesses the memory 5, obtains port information corresponding to the switching instruction, and outputs the port information to the driving unit 6.
[0055]
FIG. 5 is a diagram illustrating an optical path of a cross path. For convenience, the numbers of input mirrors 105 and output mirrors 106 provided in the MEMS mirror arrays 101 and 102 are reduced. In addition, each mirror of the input mirror 105 and the output mirror 106 is described by adding a matrix [row number: column number]. This cross path is an example in which the input port number i = 4 and the output port number j = 6. The optical path A in the cross path changes the angles of the input mirror 105 and the output mirror 106 as shown.
[0056]
At this time, the deflection angles of the input mirror 105-4 and the output mirror 106-6 to be switched are determined with reference to the optical offset (step S9). The deflection control amount calculation means 4d reads the optical offset information measured in step S6 from the memory 5, and calculates the deflection control amount of the cross path (the optimum drive voltage for the cross path) (step S10).
[0057]
The deflection control amount of the cross path satisfying i ≠ j is calculated based on the following equation (2).
[0058]
V = √ ((θ + θ_off) / A)… (2)
Where θ_off: Optical offset.
[0059]
Since the above equation (2) includes the optical offset, the deflection control amount V can be calculated with higher accuracy than when the optical offset is not considered.
[0060]
Next, the input port receiving the switching instruction and the deflection control amount corresponding to the output port are stored in a storage unit (not shown), and the drive unit 6 is executed so as to have the deflection control amount. The changing means of the input mirror 105-4 and the output mirror 106-6 is driven to change the deflection angle (step S11). Thereby, an optical path A of light as shown in FIG. 5 is formed. At this time, the light detector 3 detects the light receiving level of the optical signal output from the port 6 (104-6) of the collimator array 104 corresponding to the output port number j = 6 (step S12).
[0061]
Then, it is determined whether or not the optimum point at which the light receiving level of the optical signal at this time is highest has been obtained (step S13). The determination of the optimum point is performed by executing the feedback control (Step S13: No to Step S11 to Step S12) returning to Step S11 a plurality of times. As in the case of the through-pass, in one feedback control, the light receiving level obtained when the drive voltage for the deflecting means is changed by α is detected, and it is determined whether the light receiving level has become higher than the previous light receiving level.
[0062]
In this feedback control, a limit number N is determined (step S14). Therefore, the feedback control is performed a predetermined number of times during the period until the number of times N is reached (step S14: Yes). If the number of times of the feedback control is equal to or greater than the limit number N (step S14: No), the input mirror 105-4 and the output mirror 106-6 to be switched have not been normally angle-changed, or It is conceivable that an abnormality has occurred in the optical fiber having the port numbers i = 4 and j = 6.
[0063]
In this case, the process returns to step S8, in which it is determined that the optimum point at the corresponding port number i = 4, j = 6 cannot be obtained, and an instruction to switch to the next combination of ports to be tested is issued. At this time, the optical switch test apparatus 1 may write a predetermined value indicating “untestable” or “unusable” in the storage area allocated to the memory 5 or list the untestable ports in a list. .
[0064]
Then, when the optimum point is obtained (Step S13: Yes), the process proceeds to the structure parameter calculation process. Here, the deflection angle of the deflection unit when the optimum point is obtained will be described. For example, if the position of the input / output mirror to be used is shifted by one row in the matrix [row number n: column number m] and the required deflection angle of the deflection means is Δx, as shown in FIG. n: m], OUT [n + N: m] In order to connect a cross path using a mirror having a difference of N from the above equation (1),
[0065]
Δx × N = A × V_N ²  … (3)
[0066]
Deflection control amount V_Nis necessary. Similarly, when there is a difference of (N + 1) rows like IN [n: m] and OUT [n + (N + 1): m],
[0067]
Δx × (N + 1) = A × V_{N + 1} ²  … (4)
[0068]
Deflection control amount V_{N + 1}is necessary.
[0069]
[3] Calculation of structural parameter A
By the above-described processing, of the input mirror 105 of the MEMS mirror array 101 on the input side and the output mirror 106 of the MEMS mirror array 102 on the output side shown in FIGS. In the input mirror 105 and the output mirror 106, the exchange of the input port and the output port is established in two or more paths.
[0070]
Next, for the input mirror 105 and the output mirror 106, a mirror structural parameter A is calculated (step S15). The structure parameter calculation means 4c reads the deflection angle and the deflection control amount from the corresponding area of the storage means, and calculates the structure parameter A. The structural parameter A can be obtained by the following equation (5) based on the above equations (3) and (4).
[0071]
Δx = A (V_{N + 1} ²-V_N ²)
∴A = Δx / (V_{N + 1} ²-V_N ²…… (5)
[0072]
The value of the structural parameter A is calculated for the input mirror 0105 and the output mirror 106 and stored in the storage parameter storage area 5b of the input mirror and the storage parameter storage area 5c of the output mirror of the memory 5, respectively.
[0073]
FIG. 6 is a chart for explaining the variation of the deflection angle with respect to the deflection control amount. As shown in FIG. 6A, the input mirror 105 and the output mirror 106 have characteristic curves in which the deflection angle with respect to the deflection control amount (drive voltage) is represented by a quadratic function. This figure shows only one of the two axial directions in which the angle of the mirror can be changed. Since the input mirror 105 and the output mirror 106 vary in the structural parameter A, the respective mirrors may have different characteristic curves as shown in FIG. 6B. In this figure, characteristic curves of different port numbers 1 and 2 of the input mirror 105 are shown as an example.
[0074]
The input mirror 105 and the output mirror 106 supply a driving voltage having a deflection angle of plus (+) when the angle is changed to one and the deflection voltage when the angle is changed to the other, with the driving voltage being 0 as the center when not driving. A driving voltage having a negative (-) angle is supplied. However, the input mirror 105 and the output mirror 106 may have asymmetric characteristic curves on the left and right (plus and minus) with the drive voltage 0 at the center, as shown in the figure. When the structural parameter A is calculated for such an input mirror 105 and an output mirror 106 on the basis of a characteristic curve symmetrical to the left and right, an error occurs in the calculated value of the deflection control amount.
[0075]
For this reason, the structure parameter A of the memory 5 obtained by the above equation (5) is read and used each time the deflection control amount for the third and subsequent paths is calculated, such as each time a cross path is connected. Since the structural parameter A of the input mirror 105 and the output mirror 106 can be calculated for a mirror in which two arbitrary paths have been established, it is necessary to repeat the calculation for each of the input mirror 105 and the output mirror 106 in which the paths have been established. Thereby, the accuracy of the structural parameter A can be improved.
[0076]
In the above description, as shown in Expressions (3) and (4), the calculation of the structural parameter A corresponding to the displacement in the row direction in the matrix of the input mirror 105 is performed. By the same operation, the structural parameter A can be highly accurate also in the column direction of the input mirror 105 and the row and column directions of the output mirror 106.
[0077]
Then, it is determined whether the calculation of the deflection angles and the structural parameters for all the combinations of the input ports related to the cross path is completed (step S16). If the calculation of the deflection angles and the structural parameters for all cross paths has not been completed (step S16: No), the process returns to step S8. When the measurement of all the output ports corresponding to the cross path is completed (step S16: Yes), the calculation of the deflection angles and the structural parameters for all the combinations of the port numbers i and j is completed.
[0078]
As described above, when testing the deflection control amount of the optical switch 100, it is possible to calculate the deflection control amount by correcting the characteristic variation of the deflection means of the MEMS mirrors 101 and 102. In particular, since the optical offset of the deflecting means is calculated at the time of the through-pass, and the deflection control amounts in all the cross paths are obtained using the optical offsets, the accuracy of the deflection control amount can be improved and the test time can be reduced. .
[0079]
Next, the amount of data stored in the memory 5 will be described. To calculate the deflection control amount, the input port and its corresponding output port, optical offset θ_off, Structural parameter A is required. The information of the input port and the output port for switching is determined by the positional relationship between the input and output ports.
[0080]
As shown in FIG. 3, when the number of input ports is N and the number of output ports is N, the optical offset θ_offIs a total of 4N of the X-axis and Y-axis of the input mirror 105 and the X-axis and Y-axis of the output mirror 106 for N cases where the input port number i and the output port number j at the time of the through pass match (i = j). Data amount. The structure parameter A has a total of 4N data amounts of four axes for each of the number N of input ports of the input mirror 105. Similarly, for the output mirror 106, the structural parameter A has a total of 4N data amounts of four axes for each of the number N of output ports. As a result, the memory 5 stores these optical offsets θ_offAnd a total of 12N parameters for the structural parameter A are stored. The deflection control amount is determined by the optical offset θ_offIs calculated by the control means 4a based on the structural parameter A.
[0081]
In particular, when the number of input / output ports of the optical switch 100 increases, the deflection control amount stored in the memory 5 increases. However, according to the present invention, the deflection control amount can be calculated by optimizing the data content stored in the memory 5.
[0082]
That is, the deflection control amount when a switching instruction for setting the input / output port is received can be calculated by the above equation (2), and the deflection angle of the deflection means is determined by the positions of the input port and the output port. Therefore, the deflection control amount can be calculated based on each of the above equations (2) to (5) only by using the memory 5 having a total of 12N storage areas described above. In particular, as shown in FIG. 3, there is no need to store parameters relating to all combinations of input ports and output ports, and there are optical paths for N input / output ports i and j corresponding to the through paths (i = j). It is only necessary to store the offset, the structural parameter A for N input ports i (input mirrors 105) and the structural parameter A for N output ports j (output mirrors 106).
[0083]
FIG. 7 is a chart for explaining the number of parameters stored in the memory. According to the method according to the above procedure of the present invention, only 12N parameters are required. On the other hand, the number of parameters in the conventional method is 4N as described with reference to FIG.²Individual. Thus, according to the method of the present invention, when the number of input / output ports is three or more, the memory capacity of the memory 5 can be reduced as compared with the conventional case, and the difference becomes more noticeable as the number of ports increases. For example, when the number of ports is 100, the method of the present invention can reduce the memory amount by 10 times or more as compared with the conventional method.
[0084]
According to the test method described above, the calculation of the optical offset is performed only for each input / output port corresponding to the through path, and the structural parameter is calculated using the optical offset during the cross pass. The time can be completed in about one (minute) per pass, and the test time per pass can be reduced to one-fifth as compared with the related art.
[0085]
The optical switch test apparatus 1 described above has a configuration in which N input / output ports of the optical switch 100 are individually connected to the light source 2 and the photodetector 3 using the optical fibers 10 and 11. However, the present invention is not limited thereto, and an optical switch (not shown) may be provided between the light source 2 and the optical switch 100 and between the optical switch 100 and the photodetector 3. The light output from the light source 2 is selectively output from a single optical fiber 10 to an input port under test via an optical switch. Similarly, the light of the output port under test of the optical switch 100 is selectively taken out via the optical switch and outputted to the photodetector 3 via the single optical fiber 11. According to this configuration, the photodetector 3 does not need to be provided with a number of light receiving element arrays equal to the number N of ports of the optical switch 100, and can be constituted by a single light receiving element.
[0086]
Next, an optical signal switching device according to the present invention will be described. The optical signal switching device switches an optical signal channel (system) on an optical transmission line. FIG. 8 is a block diagram showing the configuration of the optical signal exchange device of the present invention. The optical switch 100 that has been tested by the optical switch test apparatus 1 described above is incorporated in the optical signal exchange apparatus 20.
[0087]
The optical signal switching device 20 is provided in a state where the optical switch 100 is inserted into the optical transmission path 21. The optical transmission line 21 includes N optical fibers, and a different channel is assigned to each optical fiber. The optical switch 100 performs the above-described optical path switching for the N channels of the optical transmission path 21. The optical switch 100 transmits an optical signal while maintaining the same channel during a through path, and inputs an optical signal during a cross path. Output from a different channel than the channel that was set. The “channel” has the same meaning as the “port” used in the optical switch 100.
[0088]
The optical signal exchange device 20 includes a photodetector 22, a control unit 23, a drive unit 24, and a memory 25. The photodetector 22 is arranged at a position subsequent to the optical switch 100 on the optical transmission path 21. The photodetector 22 is constituted by a monitor PD array, and individually detects N optical signals after passing through the optical switch 100 on the optical transmission line 21. The photodetector 22 outputs most of the optical signal on the optical transmission line 21, for example, 95% of the input optical signal intensity to the optical transmission line 21, and outputs the remaining 5% to a photodiode (PD) or the like. And output it. The PD outputs an electric signal (photocurrent; current signal) corresponding to the level of each output optical signal, and a current / voltage converter (not shown) converts the electric signal of the PD into a voltage signal and outputs the voltage signal to the control unit 23. I do. The photodetector 22 individually detects the light receiving levels of the optical signals of the N systems of the optical transmission line 21 and outputs a detection signal to the control unit 23. The control unit 23 has N ports and scans and takes in the detection signals input to the N ports in a time-division manner.
[0089]
FIG. 9 is a chart showing data contents of a memory in the optical signal switching device. The memory 25 stores deflection control amounts obtained by the test of the optical switch test apparatus 1 and corresponding to all combinations of the input port number and the output port number of the optical switch 100.
[0090]
The optical switch test apparatus 1 has an optical offset θ_offAnd the deflection control amount (driving voltage V) is calculated based on the structural parameter A, the deflection control amount is stored in the above-described memory 5, and the memory 5 may be mounted on the optical signal exchange device 20. However, the present invention is not limited to this, and a configuration may be adopted in which data is transferred from an external device such as the optical switch test device 1 and written into the empty memory 25 in which a writing unit (not shown) is already mounted.
[0091]
The control unit 23 is configured by, for example, an ASIC (Application Specific Integrated Circuit) such as an FPGA (Field Programmable Gate Arrays). The control unit 23 controls the driving of the optical switch 100 to switch the optical signal on the optical transmission line 21. Specifically, at the time of channel switching, the deflection control amounts of the input mirror 105 and output mirror 106 (see FIG. 13) corresponding to the input / output ports are read from the memory 25 and output to the optical switch 100 via the drive unit 24. I do.
[0092]
Since this deflection control amount is obtained by actually testing the optical switch 100 by the optical switch test apparatus 1, it is possible to minimize the optical loss for all the channels only by using this deflection control amount. it can. However, when the optical signal switching device 20 is actually operated, even when the deflection control amount is the same due to a change in the environmental temperature of the optical switch 100 or the like, the operation of the optical signal switching device 20 and the operation of the optical switch 100 are not performed. At times, the deflection angles of the input mirror 105 and the output mirror 106 are different, and a predetermined light loss occurs. To cope with this, the control unit 23 executes stabilization control of the optical output level after switching of the optical signal. Specifically, all the ports of the optical switch 100 are scanned to monitor the light receiving level of the optical signal. Then, in order to keep the optical loss of the optical switch 100 at a minimum, feedback control for outputting a predetermined deflection control amount to the drive unit 24 is performed. Details of this feedback control will be described later.
[0093]
The drive unit 24 receives the deflection control amount output from the control unit 23, converts this into a drive voltage V that is an analog control amount, and drives a deflection unit (not shown) of the optical switch 100. In accordance with the drive voltage V, the input mirror 105 of the MEMS mirror array 101 and the output mirror 106 of the MEMS mirror array 102 constituting the optical switch 100 are changed in angle in two axes (X-axis, Y-axis). You.
[0094]
Next, stabilization control of the optical output level by the optical signal switching device 20 will be described. During operation of the optical transmission line 21, the control unit 23 of the optical signal switching device 20 monitors the light receiving levels of the optical signals of all the output ports of the optical switch 100. In this operation, a through-path or cross-path optical path A (see FIG. 5) is formed between each input port and output port of the optical switch 100.
[0095]
In the memory 25, the deflection control amounts of the input mirror 105 and the output mirror 106 corresponding to the through path are stored by the offset amount, and the deflection control amounts of the input mirror 105 and the output mirror 106 corresponding to the cross path store a predetermined value. Suppose you have been. The control unit 23 reads the deflection control amounts of the input mirror 105 and the output mirror 106 corresponding to these through paths or cross paths, and outputs them to the drive unit 24. The drive unit 24 supplies a drive voltage V corresponding to the deflection control amount to the deflection means of the input mirror 105 and the output mirror 106. The deflecting unit changes the angle between the input mirror 105 and the output mirror 106 so as to form the optical path A of the set cross path.
[0096]
As described above, the optical signal switching device 20 is operated in a state where the optical signal of the optical transmission line 21 can be switched to another channel by switching the optical switch 100. FIG. 10 is a flowchart showing the stabilization control of the optical output level by the optical signal switching device. The figure describes the stabilization control of the optical output level for one optical path A during operation. At this time, one certain path is either a through path or a cross path, but the following stabilization control is performed regardless of whether the path is a through path or a cross path.
[0097]
First, the control unit 23 reads the deflection control amount from the memory 25, supplies the read deflection control amount to the drive unit 24, and switches the optical switch 100 (step S20). The driving unit 24 converts the deflection control amount into a driving voltage V and supplies the driving voltage V to the corresponding input mirror 105 and output mirror 106 deflecting means. Since the deflection control amount at this time is calculated based on the test result by the optical switch test apparatus 1, it is theoretically the optimum point with the least light loss. However, the optical switch 100, the control unit 23, the driving unit 24, and the like are affected by changes in the environmental temperature and the like of the optical signal switching device 20 during operation. Therefore, the control based on the deflection control amount read from the memory 25 may not be able to obtain the optimum point of the optical loss.
[0098]
For this reason, the control unit 23 acquires the light receiving level of the optical signal of the output port corresponding to this path from the photodetector 22 (Step S21). Thereafter, a process of acquiring the light receiving level of the optical signal while varying the angle between the input mirror 105 and the output mirror 106 is performed. At this time, the deflection control amount is increased or decreased based on the deflection control amount read from the memory 25, and the angle between the input mirror 105 and the output mirror 106 is changed based on the current angle. Here, since the angle of the input mirror 105 and the output mirror 106 can be changed in the directions of two axes (X axis, Y axis), the X axis of the input mirror 105 is set to the X1 axis, the Y axis is set to the Y1 axis, and the output mirror 106 is set. In the following description, the X axis will be described as the X2 axis, and the Y axis will be described as the Y2 axis.
[0099]
First, the drive voltage V for driving the X1-axis supplied to the deflecting means of the input mirror 105 is increased (+ α) by the voltage value α with respect to the current voltage (step S22). At this time, it is determined whether the light receiving level of the optical signal has increased (step S23). The increasing direction of this voltage is the positive direction of the drive voltage V shown in FIG. Then, when the light receiving level of the current optical signal has increased (step S23: Yes), the process returns to step S22, and the process of increasing by the voltage value α is repeated. Thereby, as shown in FIG. 4, a peak P of the light receiving level of the optical signal is obtained. After detecting the peak P, when the drive voltage V is increased, the light receiving level starts to decrease.
[0100]
Therefore, when the light receiving level is increased or decreased after the increase (step S23: No), the drive voltage V of the X1 axis is decreased (−α) by the voltage value α that has been increased once (step S24). The increasing direction of this voltage is the minus direction of the drive voltage V shown in FIG. Thereby, an optimum point where the light receiving level of the X1 axis of the input mirror 105 is the highest and light loss is small can be obtained.
[0101]
Next, the drive voltage V for driving the X2-axis supplied to the deflecting means of the output mirror 106 is increased (+ α) by the voltage value α with respect to the current voltage (step S25). At this time, it is determined whether the light receiving level of the optical signal has increased (step S26). Then, when the light receiving level of the current optical signal increases (step S26: Yes), the process returns to step S25, and the process of increasing by the voltage value α is repeated.
[0102]
As described above, when the light receiving level increases or becomes the same or decreases (Step S26: No), the drive voltage V of the X2 axis is decreased (−α) by the voltage value α that has been increased once (Step S27). . As a result, an optimum point where the light receiving level of the output mirror 106 in the X2 axis is the highest and light loss is small can be obtained.
[0103]
Next, the drive voltage V for driving the Y1-axis supplied to the deflecting means of the input mirror 105 is increased (+ α) by the voltage value α with respect to the current voltage (step S28). At this time, it is determined whether the light receiving level of the optical signal has increased (step S29). Then, when the light receiving level of the current optical signal increases (step S29: Yes), the process returns to step S28, and the process of increasing by the voltage value α is repeated.
[0104]
As described above, when the light reception level increases or remains the same or decreases (step S29: No), the drive voltage V of the Y1 axis is decreased (−α) by the voltage value α that has been increased once (step S30). . Thereby, the optimum point where the light receiving level of the input mirror 105 in the Y1 axis is the highest and the light loss is small can be obtained.
[0105]
Next, the drive voltage V for driving the Y2 axis supplied to the deflecting means of the output mirror 106 is increased (+ α) by the voltage value α with respect to the current voltage (step S31). Then, at this time, it is determined whether the light receiving level of the optical signal has increased (step S32). Then, when the light receiving level of the current optical signal increases (step S32: Yes), the process returns to step S31, and the increase of the voltage value α is repeated.
[0106]
As described above, when the light reception level increases or becomes the same or decreases (Step S32: No), the drive voltage V of the Y2 axis is decreased (−α) by the voltage value α that has been increased once (Step S33). . Thereby, the optimum point where the light receiving level of the output mirror 106 in the Y2 axis is the highest and the light loss is small can be obtained. Thereafter, the process returns to step S22, and the above processes are repeated.
[0107]
According to the light output level stabilization control described above, the optimum point for each of the X1 and Y1 axes of the input mirror 105 and the X2 and Y2 axes of the output mirror 106 can be sequentially obtained. it can. As described above, by detecting the light receiving level while changing the angle of the input mirror 105 and the output mirror 106 corresponding to the port whose channel is switched by the optical switch 100 in the directions of the two axes (X axis and Y axis), the optical signal exchange is performed. Even if the environmental temperature of the device 20 changes, the optical loss of the optical signal of the switched channel can always be reduced.
[0108]
Next, another example of stabilization control of the optical output level by the optical signal switching device will be described. FIG. 11 is a flowchart illustrating another example of stabilization control of the optical output level by the optical signal switching device. In this control, for the X1 axis and the Y1 axis of the input mirror 105 and the X2 axis and the Y2 axis of the output mirror 106, the processing for finding the optimum point for each axis is repeated once, and the optimum point is obtained. It goes.
[0109]
First, the control unit 23 reads the deflection control amount from the memory 25, supplies the read deflection control amount to the drive unit 24, and switches the optical switch 100 (step S41). Then, the light receiving level of the optical signal of the output port corresponding to the path whose channel has been switched is obtained from the photodetector 22 (step S42). Thereafter, a process of detecting a change in the light receiving level of the optical signal while varying the angle between the input mirror 105 and the output mirror 106 is performed. At this time, the deflection control amount is increased or decreased based on the deflection control amount read from the memory 25, and the angle between the input mirror 105 and the output mirror 106 is changed based on the current angle.
[0110]
First, the drive voltage V for driving the X1-axis supplied to the deflecting means of the input mirror 105 is increased (+ α) by the voltage value α with respect to the current voltage (step S43). At this time, it is determined whether the light receiving level of the optical signal has increased (step S44). The increasing direction of this voltage is the positive direction of the drive voltage V shown in FIG. Then, when the light receiving level of the current optical signal increases (step S44: Yes), the process proceeds to control of the X2 axis of the output mirror 106 (step S46). On the other hand, when the light receiving level of the current optical signal is the same or decreases (step S44: No), the drive voltage V of the X1 axis is decreased (-α) by the voltage value α that has been increased once. The drive voltage is returned to V (step S45). The increasing direction of this voltage is the minus direction of the drive voltage V shown in FIG.
[0111]
When the light receiving level increases, the light receiving level of the optical signal of the input mirror 105 in the X1 axis can be made closer to the peak P shown in FIG. On the other hand, if the driving voltage V is increased in a state away from the peak P, the light receiving level is reduced.
[0112]
Next, the drive voltage V for driving the X2 axis, which is supplied to the deflecting means of the output mirror 106, is increased (+ α) by the voltage value α with respect to the current voltage (step S46). At this time, it is determined whether the light receiving level of the optical signal has increased (step S47). If the light receiving level of the current optical signal has increased (step S47: Yes), the process proceeds to the control of the Y1 axis of the input mirror 105 (step S49). On the other hand, if the light receiving level of the current optical signal is the same or has decreased (step S47: No), the drive voltage V of the X2 axis is decreased (−α) by the voltage value α that has been increased once. The drive voltage is returned to V (step S48).
[0113]
Next, the drive voltage V for driving the Y1-axis supplied to the deflecting means of the input mirror 105 is increased (+ α) by the voltage value α with respect to the current voltage (step S49). Then, it is determined whether the light receiving level of the optical signal has increased at this time (step S50). If the light receiving level of the current optical signal has increased (step S50: Yes), the process proceeds to the control of the Y2 axis of the output mirror 106 (step S52). On the other hand, when the light receiving level of the current optical signal is the same or decreases (step S50: No), the drive voltage V of the Y1 axis is reduced (-α) by the voltage value α that has been increased once. The drive voltage is returned to V (step S51).
[0114]
Next, the drive voltage V for driving the Y2 axis supplied to the deflecting means of the output mirror 106 is increased (+ α) by the voltage value α with respect to the current voltage (step S52). At this time, it is determined whether the light receiving level of the optical signal has increased (step S53). Then, when the light receiving level of the current optical signal increases (step S53: Yes), the process returns to step S43 again to execute the control of each axis again. On the other hand, when the light receiving level of the current optical signal is the same or decreases (step S53: No), the drive voltage V of the Y2 axis is decreased (−α) by the voltage value α that has been increased once. The drive voltage is returned to V (step S54).
[0115]
As described above, according to the above-described processing procedure, the angle change between the input mirror 105 and the output mirror 106 is repeatedly executed in the order of the X1, X2, Y1, and Y2 axes. As a result, the angle change with respect to each axis can be sequentially executed in a minimum time, and the process of finding the optimum point of a certain path can be performed quickly. In step S45, step S48, step S51, and step S54, the processing for returning the driving voltage V to the original value is performed. However, the present invention is not limited to this. A configuration may be adopted in which a voltage of a predetermined multiple, for example, twice (−2α) is supplied in the negative direction, and it is determined whether the light receiving level has increased. Thus, the optimum point can be obtained by swinging the angle of the mirror with respect to the one side and the other side (minus side) around the initially supplied drive voltage V.
[0116]
In the light output stabilization procedure shown in FIGS. 10 and 11, the mirror angles of the input mirror 105 and the output mirror 106 are changed in the order of the X1, X2, Y1, and Y2 axes. However, the angle is not limited to this, and the angle may be changed in any order as long as the angle is changed with respect to each axis in one round.
[0117]
Next, a modified example of the optical signal switching device of the present invention will be described. FIG. 12 is a block diagram showing another configuration of the optical signal exchange device of the present invention. 12, the same components as those in the configuration of FIG. 8 described above are denoted by the same reference numerals.
[0118]
In this configuration example, the parameter stored in the memory 25 is the optical offset θ_offAnd the structural parameter A. These parameters are obtained as test results executed by the optical switch test apparatus 1 described with reference to FIG. The memory 25 stores the optical offset θ_off, And a mirror structure parameter memory 25b for storing the structure parameter A. Not limited to the configuration shown in the figure, the area is divided into two using a single memory 25, and the optical offset θ_offAnd the structure parameter A may be stored.
[0119]
The control unit 23 includes a control unit 23a and a deflection control amount calculation unit 23b. The deflection control amount calculator 23b calculates the optical offset θ of the input / output port corresponding to the path of the switched channel._offAnd the structural parameter A are read from the memory 25 and these optical offsets θ_offAnd the deflection control amount is calculated using the structural parameter A. This deflection control amount is a value based on the test result of the optical switch 100.
[0120]
Then, the control unit 23a outputs the obtained deflection control amount to the drive unit 24, and sets the angles of the input mirror 105 and the output mirror 106 when the optical switch 100 is switched.
[0121]
Further, the light receiving level of the optical signal at the output port of the corresponding path is input to the deflection control amount calculating means 23b. Thus, when the optical switch 100 of the optical signal switching device 20 is switched, the optical output stabilization control is performed by obtaining the optimum point of the optical loss in the corresponding path.
[0122]
The control of the light output stabilization is the same as the procedure described with reference to FIG. 10 or 11, and the description is omitted. As described above, even when the optical signal switching device 20 calculates and obtains the deflection control amount, the optimum point of the optical loss can always be obtained in response to a change in environmental temperature or the like.
[0123]
In the above, the present invention is not limited to the above-described embodiment, but can be variously modified. For example, the optical signal switching device 20 is provided with an optical branching coupler on the optical transmission line 21 instead of the photodetector 22, splits the optical signal on the optical transmission line 21 into two, and forms an optical signal comprising a PD array on the branch side. A configuration in which a detector is provided may be employed. Further, in the above-described control of stabilizing the optical output, the configuration is such that the optimum point of the optical loss is obtained for the input / output port corresponding to the path to which the optical switch 100 has been switched. The invention is not limited to this, and the control unit 23 can sequentially scan all the ports during operation of the optical signal switching apparatus 20 and perform the above-described control of stabilizing the optical output for each port. When the number of ports of the optical switch 100 is large, the number of ports can be divided into a plurality of blocks, and the ports of the plurality of blocks can be simultaneously controlled in parallel to control the optical output.
[0124]
Further, the optical signal switching device 20 provided with the optical switch 100 used in the present invention can directly switch the wavelength-multiplexed WDM signal or switch each wavelength after demultiplexing.
[0125]
Further, the test method of the optical switch and the method of controlling the light output stabilization described above can be realized by executing a prepared program on a computer such as a personal computer or a workstation. This program is recorded on various recording media, and is executed by being read from the recording medium by a computer. The program may be a transmission medium that can be distributed via a network such as the Internet.
[0126]
As described above, the present invention provides an optical switch test apparatus and an optical switch test method that can obtain an optimal deflection control amount in all paths between an input port and an output port even if a shift occurs during assembly of an optical switch. Especially suitable for. Further, the present invention is suitable for providing an optical signal switching device and a control method of the optical signal switching device that can reduce optical loss when switching an optical signal in an optical transmission line.
[0127]
(Supplementary Note 1) Light for testing the optical characteristics of an optical switch having a plurality of input ports and output ports and deflecting an optical path to switch an optical signal between an input port and an output port corresponding to an arbitrary path. In switch test equipment,
A light source for inputting a test optical signal to each input port of the optical switch;
A photodetector that detects a light receiving level of an optical signal output from each output port of the optical switch;
Each time the optical signal of the optical switch is switched, the optimum point at which the light receiving level of the optical signal detected by the photodetector is maximized while changing the deflection state of the optical path is determined, and the state of the deflection is optimized. Control means for calculating parameters based on the optimum point;
An optical switch test device comprising:
[0128]
(Supplementary Note 2) The optical switch includes:
A first mirror having a number of tilt mirrors corresponding to the number of input ports, and first deflecting means for driving the tilt mirrors to reflect the optical signal incident from the input port in an arbitrary angle direction An array,
A number of tilt mirrors corresponding to the number of output ports, and a second deflecting means for driving the tilt mirrors and reflecting the optical signal incident from the first mirror array in an arbitrary angular direction of the output port And a second mirror array having
The control means,
The input port selected when the optical signal of the optical switch is switched, and the deflection control amount required to change the angle of the tilt mirror to form the optical path between the output port, 2. The optical switch test apparatus according to claim 1, wherein the optical switch test apparatus supplies the light to the first deflecting unit and the second deflecting unit.
[0129]
(Supplementary Note 3) The control means includes:
Deflection control amount varying means for supplying a first deflection means of the first mirror array and a second deflection means of the second mirror array by changing a deflection control amount for changing a tilt mirror angle. With
When an optical path of a through path having the same port number of the input port and the output port is formed, an angle of the tilt mirror of the first mirror array and the tilt mirror of the second mirror array is changed, and the light detector detects the tilt angle. Offset calculating means for calculating an optical offset of the first mirror array and the second mirror array based on the angular position at which the optimum point at which the received light level becomes highest is obtained;
Deflection control amount calculating means for calculating the deflection control amount for changing the angle of the tilt mirror of the input port and the output port based on the optical offset calculated by the offset calculating means;
3. The optical switch test apparatus according to claim 2, further comprising:
[0130]
(Supplementary Note 4) The control means includes:
When an optical path of a cross path having different port numbers of the input port and the output port is formed, the optical offset and the tilt mirrors of the first mirror array and the second mirror array are changed in angle, and Structural parameter calculating means for calculating structural parameters of the first mirror array and the second mirror array based on the angular position at which the optimum point at which the light receiving level detected by the detector is highest is obtained;
Deflection control for calculating the deflection control amount for changing the angle of the tilt mirror of the input port and the output port based on the optical offset calculated by the offset calculating means and the structural parameter calculated by the structural parameter calculating means Quantity calculation means,
4. The optical switch test device according to claim 3, further comprising:
[0131]
(Supplementary note 5) The optical switch test according to supplementary note 4, further comprising a memory that stores the optical offset and the structure parameter calculated by the control unit as a calculation result of the corresponding input port and output port. apparatus.
[0132]
(Supplementary Note 6) The control means includes:
5. The method according to claim 3, wherein when the optimum point is detected, a predetermined limit number is provided for the number of times that the tilt mirrors of the first mirror array and the second mirror array are changed in angle. Optical switch test equipment.
[0133]
(Supplementary Note 7) The control means includes:
When the number of times to change the angle of the tilt mirror of the first mirror array and the second mirror array exceeds the predetermined limit number, it is determined that the corresponding input port and output port are unusable, 7. The optical switch test apparatus according to claim 6, wherein information indicating that the optical switch is unusable is stored in a memory.
[0134]
(Supplementary Note 8) In the first mirror array and the second mirror array constituting the optical switch, the tilt mirror can freely change its angle in two positive and negative directions of an X axis and two positive and negative directions of a Y axis. And
The control means,
The optical switch test apparatus according to claim 3 or 4, wherein the optical switch is angle-changed in the positive and negative directions in the two axial directions during the offset calculation and the calculation of the structural parameter, and the optimum point is detected.
[0135]
(Supplementary Note 9) In an optical signal exchange apparatus provided with an optical switch for switching optical signals of a plurality of channels constituting an optical transmission line to an arbitrary other channel,
A photodetector that detects a light receiving level of an optical signal output from each output port of the optical switch;
A memory storing optical offsets and structural parameters of tilt mirrors of a first mirror array and a second mirror array constituting the optical switch;
Deflection control amount calculating means for calculating a deflection control amount for changing the angle of the tilt mirror of the first mirror array and the second mirror array based on the optical offset stored in the memory and the structural parameter When,
The deflection control amount calculated by the deflection control amount calculation means is supplied to the first deflection means of the first mirror array and the second deflection means of the second mirror array to set the angle of the tilt mirror. Driving means for changing;
Based on the deflection control amount calculated by the deflection control amount calculation means and the light reception level detected by the photodetector, the light reception level of the optical signal detected by the photodetector while changing the deflection control amount is the maximum. Control means for performing control for obtaining an optimal point,
An optical signal switching device comprising:
[0136]
(Supplementary Note 10) In the first mirror array and the second mirror array constituting the optical switch, the tilt mirror can be freely angle-changed in two positive and negative X-axis directions and two positive and negative Y-axis directions. And
The control means,
The optical signal switching device according to claim 9, wherein the optical switch is angle-changed in the positive and negative directions in the two axial directions to detect the optimum point.
[0137]
(Supplementary Note 11) The control means includes:
The optical signal switching device according to appendix 9 or 10, wherein control is performed to determine the optimum point for the input port and the output port corresponding to each switching of the optical switch.
[0138]
(Supplementary Note 12) The control means includes:
The light according to claim 9 or 10, wherein the input port and the output port corresponding to all the channels of the optical switch are sequentially scanned, and control for obtaining the optimum point is performed for all the input ports and the output ports. Signal switching equipment.
[0139]
(Supplementary Note 13) Light for testing the optical characteristics of an optical switch having a plurality of input ports and output ports and deflecting an optical path to switch an optical signal between an input port and an output port corresponding to an arbitrary path. In the test method of the switch,
An optical signal inputting step of inputting a test optical signal to each input port of the optical switch,
A light receiving level detecting step of detecting a light receiving level of an optical signal output from each output port of the optical switch;
Each time the optical signal of the optical switch is switched, the optimum point at which the light receiving level of the optical signal detected while changing the deflection state of the optical path is maximized is determined, and the deflection state is optimized based on the optimum point. A parameter calculation step of calculating parameters,
An optical switch test method, comprising:
[0140]
(Supplementary Note 14) The parameter calculation step includes:
When an optical path of a through path having the same port number of the input port and the output port is formed, an angle of the tilt mirror of the first mirror array and the tilt mirror of the second mirror array is changed, and the light detector detects the tilt angle. Appendix 13 including an offset calculating step of calculating an optical offset of the first mirror array and the second mirror array based on the obtained angular position at which the optimum point at which the light receiving level becomes the highest is obtained. The described optical switch test method.
[0141]
(Supplementary Note 15) The parameter calculation step includes:
After the execution of the offset calculation step, when an optical path of a cross path having different port numbers of the input port and the output port is formed, the calculated optical offset, the first mirror array, and the second mirror The tilt mirror of the array is changed in angle, and the structural parameters of the first mirror array and the second mirror array are changed based on the angular position at which the optimum point at which the light receiving level detected by the photodetector is highest is obtained. 15. The optical switch test method according to supplementary note 14, comprising a structural parameter calculation step of calculating.
[0142]
(Supplementary Note 16) The structural parameter calculation step includes:
16. The optical switch test method according to claim 15, wherein a structural parameter of the input port and the output port of a corresponding path is sequentially calculated each time the input port is connected to the output port.
[0143]
(Supplementary Note 17) The parameter calculation step includes:
When detecting the optimum point, when the number of times to change the angle of the tilt mirror of the first mirror array and the second mirror array exceeds a predetermined limit number, the corresponding input port and output port are used. 16. The optical switch test method according to claim 14 or 15, wherein it is determined that the optical switch is unusable, and information indicating that the optical switch is unusable is stored in the memory.
[0144]
(Supplementary Note 18) The parameter calculation step includes:
Detecting the optimum point by changing the angle of the tilt mirror of the optical switch in two positive and negative directions of the X axis and the positive and negative directions of the Y axis when the optical offset and the structural parameter are calculated; 16. The optical switch test method according to claim 14 or 15, wherein
[0145]
(Supplementary Note 19) The parameter calculation step includes:
For N combinations where the input port and the output port of the optical switch match, calculate a total of 4N optical offsets of the X axis and the Y axis of the first mirror array and the second mirror array,
For N input ports of the optical switch, a total of 4N structural parameters in the positive and negative directions of the X-axis and the positive and negative directions of the Y-axis of the first mirror array are calculated.
19. A total of 4N structural parameters in the positive and negative directions of the X-axis and the positive and negative directions of the Y-axis of the second mirror array are calculated for N output ports of the optical switch. Optical switch test method.
[0146]
(Supplementary Note 20) The parameter calculation step includes:
A deflection control amount for calculating a deflection control amount for changing the angle of the tilt mirror of the input port and the output port based on the optical offset calculated in the offset calculation step and the structure parameter calculated in the structure parameter calculation step. 20. The optical switch test method according to claim 19, comprising an operation step.
[0147]
(Supplementary note 21) The storage apparatus according to supplementary note 19, further comprising a memory storing step of storing the optical offset and the structure parameter calculated in the parameter calculating step in a memory as a calculation result of the corresponding input port and output port. Optical switch test method.
[0148]
(Supplementary note 22) The optical switch test according to supplementary note 20, further comprising a memory storing step of storing in a memory a calculation result of an input port and an output port corresponding to the deflection control amount calculated in the parameter calculation step. Method.
[0149]
(Supplementary note 23) In a control method of an optical signal switching device provided with an optical switch for switching an optical signal of a plurality of channels constituting an optical transmission line to an arbitrary other channel, the optical signal is output from each output port of the optical switch. A light receiving level detecting step of detecting a light receiving level of the optical signal;
The tilt mirror of the first mirror array and the tilt mirror of the second mirror array is set based on the optical offset of the tilt mirror of the first mirror array and the tilt mirror of the second mirror array and the default value of the structural parameter. A deflection control amount calculating step of calculating a deflection control amount for changing the angle,
The deflection control amount calculated in the deflection control amount calculation step is supplied to a first deflecting unit of the first mirror array and a second deflecting unit of the second mirror array to set the angle of the tilt mirror. A driving process to be changed;
Based on the deflection control amount calculated in the deflection control amount calculation step and the light reception level detected in the light reception level detection step, an optimum point at which the light reception level of the optical signal detected while changing the deflection control amount is maximum. And a control step of executing a control to be sought.
[0150]
(Supplementary Note 24) The controlling step includes:
The tilt point mirrors of the first mirror array and the second mirror array that constitute the optical switch are respectively angle-changed in the positive and negative directions of the X axis and in the positive and negative directions of the Y axis to determine the optimum point. 24. The control method for an optical signal switching device according to supplementary note 23, wherein the control is performed.
[0151]
(Supplementary Note 25) The control step includes:
25. The control method of an optical signal switching device according to claim 23 or 24, wherein control is performed to obtain the optimum point for the input port and the output port corresponding to each switching of the optical switch.
[0152]
(Supplementary Note 26) The control means includes:
25. The light according to claim 23 or 24, wherein the input port and the output port corresponding to all the channels of the optical switch are sequentially scanned, and control for obtaining the optimum point is performed for all the input ports and the output ports. A method for controlling a signal switching device.
[0153]
(Supplementary Note 27) An optical switch that has a plurality of input ports and output ports and switches an optical signal between an input port and an output port corresponding to an arbitrary path is mounted on an optical signal exchange device after testing optical characteristics. A method of controlling an optical signal switching device provided on an optical transmission line and switching optical signals of a plurality of channels to any other channel,
Testing the optical properties of the optical switch includes:
An optical signal inputting step of inputting a test optical signal to each input port of the optical switch,
A light receiving level detecting step of detecting a light receiving level of an optical signal output from each output port of the optical switch;
Parameter calculation for calculating an optimum point at which the light receiving level of an optical signal detected while changing the deflection state of the optical switch is maximum, and calculating an optical offset and a structure parameter for optimizing the deflection state based on the optimum point. Process and
A parameter storing step of storing the optical offset and the structural parameter calculated in the parameter calculating step in a memory,
The control by the optical signal switching device,
A mounting step of mounting the optical switch and the memory after the test of the optical characteristics,
A light receiving level detecting step of detecting a light receiving level of an optical signal output from each output port of the optical switch;
A deflection control amount for changing an angle of a tilt mirror of a first mirror array and a tilt mirror of a second mirror array provided in the optical switch is calculated based on the optical offset stored in the memory and the structural parameter. A deflection control amount calculating step of
The deflection control amount calculated in the deflection control amount calculation step is supplied to first deflecting means of the first mirror array and second deflecting means of the second mirror array to change the angle of the tilt mirror. A driving step for
Based on the deflection control amount calculated by the deflection control amount calculation means and the light reception level detected by the photodetector, the light reception level of the optical signal detected by the photodetector while changing the deflection control amount is the maximum. A control step of performing control for obtaining a certain optimal point;
A method for controlling an optical signal switching device, comprising:
[0154]
(Supplementary Note 28) After testing the optical characteristics of an optical switch that has a plurality of input ports and output ports and switches an optical signal between an input port and an output port corresponding to an arbitrary path, the optical switch is mounted on an optical signal switching device. A method of controlling an optical signal switching device provided on an optical transmission line and switching optical signals of a plurality of channels to any other channel,
Testing the optical properties of the optical switch includes:
An optical signal inputting step of inputting a test optical signal to each input port of the optical switch,
A light receiving level detecting step of detecting a light receiving level of an optical signal output from each output port of the optical switch;
Parameter calculation for calculating an optimum point at which the light receiving level of an optical signal detected while changing the deflection state of the optical switch is maximum, and calculating an optical offset and a structure parameter for optimizing the deflection state based on the optimum point. Process and
A deflection control amount for changing an angle of a tilt mirror of the first mirror array and the tilt mirror of the second mirror array provided in the optical switch is calculated based on the optical offset and the structure parameter calculated in the parameter calculation step. A deflection control amount calculation step;
Storing a deflection control amount calculated in the deflection control amount calculation step in a memory,
The control by the optical signal switching device,
A mounting step of mounting the optical switch and the memory after the test,
A light receiving level detecting step of detecting a light receiving level of an optical signal output from each output port of the optical switch;
A driving step of supplying the deflection control amount stored in the memory to a first deflection unit of the first mirror array and a second deflection unit of the second mirror array, and changing an angle of the tilt mirror; ,
Based on the deflection control amount and the light reception level detected by the photodetector, control is performed to find an optimum point at which the light reception level of the optical signal detected by the photodetector is maximum while changing the deflection control amount. Control process;
A method for controlling an optical signal switching device, comprising:
[0155]
(Supplementary Note 29) The attaching step
28. The control method for an optical signal switching device according to claim 27, wherein the optical offset and the structural parameters are stored in a previously mounted empty memory by data transfer.
[0156]
(Supplementary Note 30) The mounting step includes:
29. The control method of an optical signal switching device according to claim 28, wherein the deflection control amount is stored in a previously mounted empty memory by data transfer.
[0157]
【The invention's effect】
As described above, according to the optical switch test apparatus of the present invention, since the optical path of the through-path is formed and the optical offset due to the deviation at the time of assembling the optical switch is calculated, the deflection control amount of each output port with respect to each input port is calculated. Can be accurately calculated. Further, each time the optical path of the cross path is formed, the structural parameters of the tilt mirror of the input port and the output port can be calculated using the calculated optical offset, and the optical characteristics of the tilt mirror vary. Even with this, the structure parameters can be made more precise. Further, since the number of times of controlling the deflection unit by detecting the light receiving level to obtain the deflection control amount can be reduced, the optical characteristics of the optical switch can be efficiently tested in a short time. . Further, since the structure parameters are calculated and obtained based on the optical offsets corresponding to the number of input / output ports corresponding to the through paths, the data amount of these optical offsets and the structure parameters can be reduced, and the capacity of the memory for storing data is not taken up. In addition, even if the size of the optical switch becomes large, the effect that the capacity required for the memory can be reduced can be obtained.
[0158]
According to the optical switch test apparatus of the present invention, the optical loss can be minimized by switching the optical switch by calculating the deflection control amount based on the optical offset and the structural parameter, which are the optical characteristics of the optical switch, Since the control for obtaining the optimum point of the light receiving level is performed while changing the deflection control amount for driving the tilt mirror, there is an effect that the light loss can always be minimized even when the environmental temperature or the like changes.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an optical switch test apparatus according to the present invention.
FIG. 2 is a flowchart illustrating a test procedure of a switch by the optical switch test apparatus.
FIG. 3 is a chart showing data contents stored in a memory;
FIG. 4 is a chart showing a change state of light loss when an angle is changed.
FIG. 5 is a diagram illustrating an optical path of a cross path.
FIG. 6 is a chart for explaining a variation of a deflection angle with respect to a deflection control amount;
FIG. 7 is a chart for explaining the number of parameters stored in a memory;
FIG. 8 is a block diagram showing a configuration of an optical signal exchange device of the present invention.
FIG. 9 is a chart showing data contents of a memory in the optical signal switching device;
FIG. 10 is a flowchart illustrating stabilization control of an optical output level by the optical signal exchange device.
FIG. 11 is a flowchart showing another example of stabilization control of the optical output level by the optical signal exchange device.
FIG. 12 is a block diagram showing another configuration of the optical signal exchange device of the present invention.
FIG. 13 is a perspective view showing an optical switch.
FIG. 14 is a flowchart illustrating a test procedure for obtaining a deflection control amount of an optical switch according to the related art.
FIG. 15 is a table showing memory contents for storing deflection control amounts;
[Explanation of symbols]
1 Optical switch test equipment
2 Light source
3 Photodetector
4 control unit
4a Control means
4b Offset calculation means
4c Structure parameter calculating means
4d deflection control amount calculation means
5 memory
5a Optical offset storage area
5b Input mirror structure parameter storage area
5c Output mirror structure parameter storage area
6 Drive
10,11 Optical fiber
20 Optical signal switching equipment
21 Optical transmission line
22 Photodetector
23 Control unit
23a control means
23b Deflection control amount calculation means
24 drive unit
25 memory
100 optical switch
101,102 MEMS mirror array
103,104 Collimator array
105,106 tilt mirror

Claims (5)

An optical switch test apparatus that has a plurality of input ports and output ports and that tests the optical characteristics of an optical switch that deflects an optical path to switch an optical signal between an input port and an output port corresponding to an arbitrary path. ,
A light source for inputting a test optical signal to each input port of the optical switch;
A photodetector that detects a light receiving level of an optical signal output from each output port of the optical switch;
Each time the optical signal of the optical switch is switched, the optimum point at which the light receiving level of the optical signal detected by the photodetector is maximized while changing the deflection state of the optical path is determined, and the state of the deflection is optimized. Control means for calculating parameters based on the optimum point;
An optical switch test device comprising: The optical switch,
A first mirror having a number of tilt mirrors corresponding to the number of input ports, and first deflecting means for driving the tilt mirrors to reflect the optical signal incident from the input port in an arbitrary angle direction An array,
A number of tilt mirrors corresponding to the number of output ports, and a second deflecting means for driving the tilt mirrors and reflecting the optical signal incident from the first mirror array in an arbitrary angular direction of the output port And a second mirror array having
The control means,
The input port selected when the optical signal of the optical switch is switched, and the deflection control amount required to change the angle of the tilt mirror to form the optical path between the output port, 2. The optical switch test apparatus according to claim 1, wherein the light is supplied to the first deflecting unit and the second deflecting unit. In an optical signal switching device provided with an optical switch that switches an optical signal of a plurality of channels constituting an optical transmission line to any other channel,
A photodetector that detects a light receiving level of an optical signal output from each output port of the optical switch;
A memory storing optical offsets and structural parameters of tilt mirrors of the first mirror array and the second mirror array constituting the optical switch;
Deflection control amount calculating means for calculating a deflection control amount for changing the angle of the tilt mirrors of the first mirror array and the second mirror array based on the optical offset stored in the memory and the structural parameters When,
The deflection control amount calculated by the deflection control amount calculation means is supplied to the first deflection means of the first mirror array and the second deflection means of the second mirror array to set the angle of the tilt mirror. Driving means for changing;
Based on the deflection control amount calculated by the deflection control amount calculation means and the light reception level detected by the photodetector, the light reception level of the optical signal detected by the photodetector while changing the deflection control amount is the maximum. Control means for performing control for obtaining an optimal point,
An optical signal switching device comprising: An optical switch test method comprising a plurality of input ports and output ports, and testing the optical characteristics of an optical switch that deflects an optical path to switch an optical signal between an input port and an output port corresponding to an arbitrary path At
An optical signal inputting step of inputting a test optical signal to each input port of the optical switch,
A light receiving level detecting step of detecting a light receiving level of an optical signal output from each output port of the optical switch;
Each time the optical signal of the optical switch is switched, the optimum point at which the light receiving level of the optical signal detected while changing the deflection state of the optical path is maximized is determined, and the deflection state is optimized based on the optimum point. A parameter calculation step of calculating parameters,
An optical switch test method, comprising: In a control method of an optical signal switching device provided with an optical switch for switching an optical signal of a plurality of channels constituting an optical transmission line to any other channel,
A light receiving level detecting step of detecting a light receiving level of an optical signal output from each output port of the optical switch;
The tilt mirror of the first mirror array and the tilt mirror of the second mirror array is set based on the optical offset of the tilt mirror of the first mirror array and the tilt mirror of the second mirror array and the default value of the structural parameter. A deflection control amount calculating step of calculating a deflection control amount for changing the angle,
The deflection control amount calculated in the deflection control amount calculation step is supplied to a first deflecting unit of the first mirror array and a second deflecting unit of the second mirror array to set the angle of the tilt mirror. A driving process to be changed;
Based on the deflection control amount calculated in the deflection control amount calculation step and the light reception level detected in the light reception level detection step, an optimum point at which the light reception level of the optical signal detected while changing the deflection control amount is maximum. A control step for performing the control desired;
A method for controlling an optical signal switching device, comprising:

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