MEMS optical switch control device

Abstract

The utility model provides an MEMS optical switch control device comprising a channel calibration table used for providing MEMS optical switch channel initial control voltage parameters; the cosine signal source is used for generating a cosine modulation voltage signal; the summator is used for superposing the initial control voltage, the cosine modulation voltage and the feedback adjustment voltage and then outputting the superposed voltage to the MEMS optical switch; the detection photodiode is used for receiving the optical signal output by the MEMS optical switch channel N and outputting a conversion power signal after photoelectric conversion; the multiplier is used for coherent amplification of the cosine modulation voltage signal and the conversion power signal and outputting a coherent signal; the first filter is connected with the multiplier, obtains the coherent signal, filters the frequency multiplication component of the coherent signal and outputs a direct current component; the integrator is used for obtaining the direct current component and integrating the obtained direct current adjustment amount as feedback adjustment voltage to be output to the summator; and the feedback adjustment voltage is output to the MEMS optical switch through the summator, so that compensation of a channel control voltage signal is realized.

Description

Technical Field

[0001] This utility model relates to the field of spectral technology, and in particular to a MEMS optical switch control device. Background Technology

[0002] 1xN channel MEMS optical switches (Micro-Electro-Mechanical Systems Optical Switches) are used for optical signal routing and switching, and are commonly used in optical communication networks for allocating and scheduling optical channels. Their working principle is as follows: Figure 1 As shown.

[0003] The functions and principles of each part are as follows:

[0004] Collimator: The input collimator converts the "Light in" into parallel light; the output collimator converges the parallel light after reflection and other operations, and couples it into the corresponding channel (Channel 1-4).

[0005] Rotating mirror: Controlled by the "MEMS controller", it rotates according to the "Switch position" command to change the direction of the reflected light, thereby guiding the input light to different output channels (Channel 1-4);

[0006] Mirror (fixed reflector): It helps to change the direction of light. In conjunction with a rotating reflector, it allows light to accurately reach the target straightener and enter the corresponding channel.

[0007] MEMS controller: Receives and processes switch position signals, drives the rotating mirror to rotate, and is the control core of the entire optical switch, determining which channel the optical signal switches to;

[0008] Channel: Represents the output path of optical signals. Through the cooperation of the above components, the input light can be flexibly switched to different channels to realize the routing selection of optical signals and support the flexible scheduling of signals in optical communication networks.

[0009] Will Figure 1 The principle is simplified to Figure 2 The structure shown reflects the input light from the input port to different output ports 0 through N by controlling a rotating mirror to rotate around the center point A. The rotation angle of the rotating mirror is proportional to the control voltage. Switching between different channels requires different MEMS control voltages. The MEMS optical switch is provided with a channel calibration table at the factory to provide the initial control voltage parameters for each channel.

[0010] When a MEMS optical switch switches between different channels, it is controlled according to the factory calibration data. However, due to vibrations during transportation / use, temperature changes, and device aging, the reflective surface of the rotating mirror of the MEMS optical switch may shift. If the MEMS optical switch is still controlled according to the factory calibration parameters, the insertion loss may increase or even the channel switching may be abnormal because the shift between the reflective surface and the input / output channel is not compensated. In addition, when the MEMS optical switch device ages or fails, the degree of aging cannot be determined and fault alarms cannot be generated, which reduces the reliability of the system.

[0011] Therefore, it is necessary to provide a MEMS optical switch control device to solve or at least partially solve the above problems. Utility Model Content

[0012] This invention provides a MEMS optical switch control device, which introduces a cosine signal source to superimpose a very small jitter on the control voltage of the MEMS optical switch. By adjusting the control voltage of the MEMS optical switch through the amplitude / frequency / phase characteristics of the output signal, the optical switch is locked in the working state with minimal insertion loss.

[0013] This utility model embodiment provides a MEMS optical switch control device, including:

[0014] Channel calibration table, used to provide initial control voltage parameters for MEMS optical switch channels;

[0015] A cosine signal source is used to generate cosine-modulated voltage signals.

[0016] The adder superimposes the initial control voltage, cosine modulation voltage, and feedback adjustment voltage of the MEMS optical switch and outputs the result to the MEMS optical switch.

[0017] The photodiode is detected, the optical signal output from the MEMS optical switch channel N is received, and the conversion power signal after photoelectric conversion is output.

[0018] A multiplier is used to coherently amplify a cosine-modulated voltage signal and a converted power signal, and outputs a coherent signal, which includes a frequency harmonic component and a DC component.

[0019] The first filter is connected to the multiplier to acquire the coherent signal, filter out the harmonic components of the coherent signal, and output the DC component.

[0020] An integrator, connected to the first filter, acquires the DC component, integrates the DC component to obtain the DC adjustment amount, and outputs the DC adjustment amount as a feedback adjustment voltage to the adder.

[0021] The feedback adjustment voltage is output to the MEMS optical switch via the adder to compensate the channel control voltage signal.

[0022] Preferably, the detection photodiode is disposed between the MEMS optical switch and the multiplier, connecting the MEMS optical switch and the multiplier, and outputting a conversion power signal after photoelectric conversion of the optical signal output by the MEMS optical switch.

[0023] Preferably, the multiplier is disposed between the detection photodiode and the first filter; the cosine signal source and the detection photodiode are connected, and the cosine modulated voltage signal output by the cosine signal source and the conversion power signal output by the detection photodiode are coherently amplified, and a coherent signal is output to the first filter.

[0024] Preferably, it further includes an 1 / N attenuator, which is connected to the cosine signal source and the adder. The 1 / N attenuator attenuates the cosine modulation voltage signal generated by the cosine signal source and outputs it to the adder to reduce the cosine modulation voltage superimposed on the MEMS optical switch.

[0025] Preferably, the system further includes a second filter, which is connected to the detection photodiode and the multiplier. The second filter is a bandpass filter with a center frequency of W, used to filter out external interference in the converted power signal.

[0026] Preferably, it further includes a coherent signal detection module, which is connected to the multiplier to acquire a coherent signal and detect the frequency harmonic component of the coherent signal; if no frequency harmonic component is detected, it indicates that the MEMS optical switch has not switched to the corresponding output port N, and the coherent signal detection module outputs a MEMS optical switch fault alarm signal.

[0027] Preferably, it also includes a device aging threshold module, which is connected to the integrator to obtain the DC adjustment amount, compares the DC adjustment amount with the set device aging threshold, and if the DC adjustment amount is greater than the set device aging threshold, the device aging threshold module outputs a MEMS optical switch aging alarm signal.

[0028] Compared with the prior art, the technical solution of this utility model embodiment has the following beneficial effects:

[0029] This utility model provides a MEMS optical switch control device that introduces a cosine signal source. By superimposing a very small jitter onto the control voltage of the MEMS optical switch, a multiplier is used to coherently amplify the output signal of the MEMS optical switch and the cosine-modulated voltage signal. The control voltage of the MEMS optical switch is adjusted based on the amplitude, frequency, and phase characteristics of the output signal, locking the MEMS optical switch in a working state with minimal insertion loss. The amplitude, frequency, and phase characteristics of the output signal are also used to determine whether the current working state of the optical switch is normal. If aging or other issues are detected, an alarm is issued in advance, allowing maintenance personnel to intervene early and avoid service interruptions during system operation, thus improving system reliability. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model, not all embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the working principle of a MEMS optical switch.

[0032] Figure 2 Simplified schematic diagram of MEMS optical switch;

[0033] Figure 3 A schematic diagram of the structure of a MEMS optical switch control device provided in one embodiment of the present invention;

[0034] Figure 4 When channel N is selected for the MEMS optical switch, the MEMS optical switch only receives the initial control voltage. Schematic diagram of the rotating mirror's rotation position;

[0035] Figure 5 When channel N is selected for the MEMS optical switch, the MEMS optical switch only receives the initial control voltage. The graph shows the control voltage and output power of the MEMS optical switch when the rotating mirror rotates from position 1 to position 3.

[0036] Figure 6 When channel N is selected for the MEMS optical switch, the initial control voltage of the MEMS optical switch is superimposed with a cosine modulation voltage. When the rotating mirror rotates from position 1 to position 3, the graph shows the control voltage and output power of the MEMS optical switch.

[0037] In the picture:

[0038] 1-Channel calibration table; 2-Cosine signal source; 3-1 / N attenuator; 4-Adder; 5-MEMS optical switch; 6-Detection photodiode; 7-Second filter; 8-Multiplier; 9-Coherent signal detection module; 10-First filter; 11-Integrator; 12-Device aging threshold module. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0040] The technical solution of this utility model will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0041] To address the problems existing in the prior art, this utility model provides a MEMS optical switch control device. It introduces a cosine signal source, adds a very small jitter to the control voltage of the MEMS optical switch, and analyzes the output signal of the optical switch using coherent detection. By analyzing the amplitude / frequency / phase characteristics of the output signal, the control voltage of the MEMS optical switch is adjusted so that the optical switch is locked in the working state with minimal insertion loss.

[0042] Figure 3 A schematic diagram of the structure of a MEMS optical switch control device provided in one embodiment of the present invention; Figure 4 When channel N is selected for the MEMS optical switch, the MEMS optical switch only receives the initial control voltage. Schematic diagram of the rotating mirror's rotation position; Figure 5 When channel N is selected for the MEMS optical switch, the MEMS optical switch only receives the initial control voltage. The graph shows the control voltage and output power of the MEMS optical switch when the rotating mirror rotates from position 1 to position 3. Figure 6 When channel N is selected for the MEMS optical switch, the initial control voltage of the MEMS optical switch is superimposed with a cosine modulation voltage. When the rotating mirror rotates from position 1 to position 3, the graph shows the control voltage and output power of the MEMS optical switch.

[0043] Now see Figure 3 This utility model provides a MEMS optical switch control device, comprising:

[0044] Channel calibration table 1 is used to provide the initial control voltage parameters for the MEMS optical switch channel;

[0045] Cosine signal source 2 is used to generate a cosine modulated voltage signal;

[0046] Adder 4 superimposes the initial control voltage, cosine modulation voltage and feedback adjustment voltage of MEMS optical switch 5 and outputs them to MEMS optical switch 5.

[0047] The photodiode 6 is detected, connected to the MEMS optical switch 5, receives the optical signal output from channel N of the MEMS optical switch 5, and outputs the conversion power signal after photoelectric conversion.

[0048] Multiplier 8 is connected to cosine signal source 2 and detection photodiode 6. It is used for coherent amplification of cosine modulated voltage signal and conversion power signal, and outputs coherent signal, which includes frequency harmonic component and DC component.

[0049] The first filter 10 is connected to the multiplier 8 to acquire the coherent signal, filter out the harmonic components of the coherent signal, and output the DC component.

[0050] Integrator 11 is connected to first filter 10 to obtain DC component, integrate DC component to obtain DC adjustment amount, and output DC adjustment amount as feedback adjustment voltage to adder 4.

[0051] The feedback adjustment voltage is superimposed by adder 4 and output to MEMS optical switch 5 to achieve compensation of channel control voltage signal.

[0052] Specifically, Channel Calibration Table 1 provides the MEMS control voltages required for switching different channels, as shown in Table 1 below:

[0053] Table 1. Factory Calibration Table for MEMS Optical Switches

[0054] Channel number MEMS control voltage 0 VCC_CH0 1 VCC_CH1 … … N VCC_CHN

[0055] Specifically, the first filter 10 is a low-pass filter used to filter out the harmonic components after coherence.

[0056] In some embodiments, the cosine-modulated voltage signal is represented as T*COS(Wt), where T is the amplitude, W is the angular frequency, and t is the time; the converted power signal is represented as R*COS(Wt+P), where R is the nonlinear coefficient, W is the angular frequency, t is the time, and P is the received phase; the multiplier amplifies the converted power signal by a factor of T / 2; the output coherent signal includes a second harmonic component and a DC component, the second harmonic component is represented as: (T*R / 2)*[COS(2Wt+P)]; the DC component is represented as: (T*R / 2)*COS(P); where T is the amplitude, W is the angular frequency, t is the time, R is the nonlinear coefficient, and P is the received phase.

[0057] In some embodiments, an I / N attenuator 3 is also included. The I / N attenuator 3 is connected to the cosine signal source 2 and the adder 4. The cosine modulation voltage signal generated by the cosine signal source 2 is attenuated and then output to the adder 4 to reduce the cosine modulation voltage superimposed on the MEMS optical switch 5. The attenuated cosine modulation voltage signal is a small disturbance, such as 0.01dB, to avoid affecting the service optical path.

[0058] In some embodiments, a second filter 7 is also included, which is connected to the detection photodiode 6 and the multiplier 8. The second filter 7 is a bandpass filter with a center frequency of W, used to filter out external interference in the converted power signal.

[0059] In some embodiments, a coherent signal detection module 9 is also included. The coherent signal detection module 9 is connected to the multiplier 8 to acquire the coherent signal and detect the frequency harmonic component of the coherent signal. If the frequency harmonic component is not detected, it indicates that the MEMS optical switch 5 has not switched to the corresponding output port N, and the coherent signal detection module 9 outputs a MEMS optical switch fault alarm signal.

[0060] In some embodiments, the device aging threshold module 12 is also included. The device aging threshold module 12 is connected to the integrator 11 to obtain the DC adjustment amount, compares the DC adjustment amount with the set device aging threshold, and if the DC adjustment amount is greater than the set device aging threshold, the device aging threshold module 12 outputs a MEMS optical switch aging alarm signal.

[0061] See Figures 4-6 Select the output of channel N of MEMS optical switch 5, find the factory calibration voltage of channel N through channel calibration table 1 and use it as the initial control voltage of channel N; input the initial control voltage into MEMS optical switch 5 as the control voltage;

[0062] If the rotating mirror of MEMS optical switch 5 rotates to position 1, it means that the rotating mirror is tilted to the left. During the process of rotating mirror rotating from position 1 to position 2, the power of output channel N continuously increases.

[0063] If the rotating mirror of MEMS optical switch 5 is rotated to position 2, it means that the rotating mirror is aligned and the power of output channel N is at its maximum when it is in position 2.

[0064] If the rotating mirror of MEMS optical switch 5 rotates to position 3, it means that the position of the rotating mirror is deviated to the right. During the process of rotating mirror rotating from position 1 to position 3, the power of output channel N continuously decreases.

[0065] When the voltage applied to the MEMS optical switch 5 is in the range of position 1 to position 2, the power of the output channel N is directly proportional to the control voltage of the MEMS optical switch 5. That is, the higher the control voltage of the MEMS optical switch 5, the greater the output.

[0066] When the voltage applied to the MEMS optical switch 5 is in the range of position 2-position 3, the power of the output channel N is inversely proportional to the control voltage of the MEMS optical switch 5. That is, the higher the control voltage of the MEMS optical switch 5, the smaller the output.

[0067] Utilizing this characteristic, a small amplitude cosine modulation signal superimposed on the control voltage of the MEMS optical switch 5 can be used to adjust the MEMS optical switch 5 by means of information such as the amplitude, phase, and frequency of the output signal, thereby maintaining the MEMS optical switch control voltage at position 2.

[0068] Specifically, the cosine-modulated voltage signal is represented as T*COS(Wt), where T is the amplitude, W is the angular frequency, and t is the time; that is, the MEMS optical switch 5 is superimposed with a tiny cosine-modulated signal T*COS(Wt);

[0069] The conversion power signal is represented as R*COS(Wt+P), where R is the nonlinear coefficient, W is the angular frequency, t is the time, and P is the receiving phase; that is, the output signal of the N-channel optical signal of the MEMS optical switch after passing through the photodiode 6 is R*COS(Wt+P).

[0070] Multiplier 8 coherently amplifies the converted power signal and the cosine-modulated voltage signal; the coherent process is expressed as: F(x)=R*COS(Wt+P)*T*COS(Wt)

[0071] =(T*R / 2)*[COS(2Wt+P)+COS(P)]

[0072] The output coherent signal includes a second harmonic component and a DC component. The second harmonic component is represented as: (T*R / 2)*[COS(2Wt+P)]; the DC component is represented as: (T*R / 2)*COS(P); where T is the amplitude, W is the angular frequency, t is the time, R is the nonlinear coefficient, and P is the received phase.

[0073] After filtering out the second harmonic component COS(2Wt) by the first filter (low-pass filter) 10, and retaining the DC component COS(-P), then F(x) = (T*R / 2)*COS(P).

[0074] As can be seen from the above, the power signal is amplified by T / 2 times through coherent processing.

[0075] Meanwhile, the adjustment direction of the MEMS optical switch 5 can be determined from the received phase P.

[0076] F(x) = (T*R / 2)*COS(P). When MEMS optical switch 5 is in position 1, P is positive and F(x) is positive, and the control voltage of MEMS optical switch increases.

[0077] F(x) = (T*R / 2)*COS(P). When MEMS optical switch 5 is in position 3, P is negative and F(x) is negative. The control voltage of MEMS optical switch 5 decreases.

[0078] Therefore, the MEMS optical switch 5 can be locked at position 2 by controlling the voltage.

[0079] In summary, the MEMS optical switch control device provided by this embodiment introduces a cosine signal source 2 to superimpose a very small jitter onto the control voltage of the MEMS optical switch 5. A multiplier coherently amplifies the output signal of the MEMS optical switch 5 and the cosine-modulated voltage signal. By utilizing the amplitude / frequency / phase characteristics of the output signal, the control voltage of the MEMS optical switch 5 is adjusted, locking the MEMS optical switch 5 in a working state with minimal insertion loss. The amplitude / frequency / phase characteristics of the output signal are also used to determine whether the current working state of the optical switch is normal. If aging or other issues occur, an early alarm is issued, allowing maintenance personnel to intervene in advance, avoiding service interruptions during system operation, and improving system reliability.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A MEMS optical switch control device, characterized in that, include: Channel calibration table, used to provide initial control voltage parameters for MEMS optical switch channels; A cosine signal source is used to generate cosine-modulated voltage signals. The adder superimposes the initial control voltage, cosine modulation voltage, and feedback adjustment voltage of the MEMS optical switch and outputs the result to the MEMS optical switch. The photodiode is detected, the optical signal output from the MEMS optical switch channel N is received, and the conversion power signal after photoelectric conversion is output. A multiplier is used to coherently amplify a cosine-modulated voltage signal and a converted power signal, and outputs a coherent signal, which includes a frequency harmonic component and a DC component. The first filter is connected to the multiplier to acquire the coherent signal, filter out the harmonic components of the coherent signal, and output the DC component. An integrator, connected to the first filter, acquires the DC component, integrates the DC component to obtain the DC adjustment amount, and outputs the DC adjustment amount as a feedback adjustment voltage to the adder. The feedback adjustment voltage is output to the MEMS optical switch via the adder to achieve compensation of the channel control voltage signal.

2. The MEMS optical switch control device according to claim 1, characterized in that, The detection photodiode is disposed between the MEMS optical switch and the multiplier, connecting the MEMS optical switch and the multiplier, and outputs a conversion power signal after photoelectric conversion of the optical signal output by the MEMS optical switch.

3. The MEMS optical switch control device according to claim 1, characterized in that, The multiplier is positioned between the detection photodiode and the first filter; it connects the cosine signal source and the detection photodiode, coherently amplifies the cosine-modulated voltage signal output from the cosine signal source and the conversion power signal output from the detection photodiode, and outputs a coherent signal to the first filter.

4. The MEMS optical switch control device according to claim 1, characterized in that, It also includes an 1 / N attenuator, which is connected to a cosine signal source and an adder. The 1 / N attenuator attenuates the cosine modulation voltage signal generated by the cosine signal source and outputs it to the adder to reduce the cosine modulation voltage superimposed on the MEMS optical switch.

5. The MEMS optical switch control device according to claim 1, characterized in that, It also includes a second filter, which is connected to the detection photodiode and the multiplier. The second filter is a bandpass filter with a center frequency of W, used to filter out external interference in the converted power signal.

6. The MEMS optical switch control device according to claim 1, characterized in that, It also includes a coherent signal detection module, which is connected to the multiplier to acquire coherent signals and detect the frequency harmonics of the coherent signals; if no frequency harmonics are detected, it indicates that the MEMS optical switch has not switched to the corresponding output port N, and the coherent signal detection module outputs a MEMS optical switch fault alarm signal.

7. The MEMS optical switch control device according to claim 1, characterized in that, It also includes a device aging threshold module, which is connected to the integrator to obtain the DC adjustment amount, compares the DC adjustment amount with the set device aging threshold, and if the DC adjustment amount is greater than the set device aging threshold, the device aging threshold module outputs a MEMS optical switch aging alarm signal.

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