Micro-motion signal detector and coherent optical module

Abstract

The embodiment of the utility model discloses a micro-motion signal detector and a coherent optical module. The micro-motion signal detector comprises at least two parallel detection modules, an isolation module and an amplification module. And each detection module comprises an optical detector and a trans-impedance amplifier which are connected in sequence. The isolation module isolates a direct current signal in the micro voltage signal transmitted by the detection module, and outputs a micro voltage signal only containing an alternating current signal. And the amplification module is connected with the output end of the isolation module and is used for receiving the micro voltage signal subjected to the isolation processing and carrying out multi-stage amplification on the micro voltage signal subjected to the isolation processing. Only one multi-stage amplification link is arranged, so that the amplitude of a micro-motion voltage signal output by each detection module is effectively enhanced, and the response sensitivity of the system to a micro-motion optical signal is improved; and the board distribution area of the high-gain micro-motion signal detector is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of coherent modulator, especially relates to a micro motion signal detector and coherent optical module. BACKGROUND

[0002] The coherent optical module is an important component in the optical communication system, and its function is to realize the transmission of optical signals. The coherent optical module usually includes light sources, modulators, amplifiers, microcontrollers and detectors and other elements. In practical applications, the modulator is used to modulate the phase, amplitude or frequency of the optical signal, so that the coherent optical module can transmit information by controlling the characteristics of light.

[0003] In order to ensure that the signal transmission of the coherent optical module has better quality and reliability, reduces the nonlinear distortion, and improves the signal transmission distance and rate, the working point of the modulator is usually stabilized near the set point. For example, the microcontroller will regulate the modulator, so that the I channel of the X direction and the I channel of the Y direction of the modulator work in the NULL (zero mode interference) point state, the Q channel of the X direction and the Q channel of the Y direction work in the NULL (zero mode interference) point state, and the main channel of the modulator works in the QUARD (quadrature interference) point state. In practical applications, the NULL static working point and the QUARD static working point will be offset due to the influence of temperature, stress, device aging and other factors, resulting in that the coherent receiver cannot normally demodulate the received coherent optical signal. In order to solve the above problems, the microcontroller of some coherent optical modules usually superimposes a micro motion signal (Dither signal, the Dither signal is usually a sine signal, but the amplitude is much smaller than that of the signal). The photoelectric converter connected to the modulator of the coherent optical module performs photoelectric conversion on the received micro motion signal, and then inputs the amplified signal to the microcontroller through the amplification circuit. The micro device calculates the received signal, adjusts the working point of the modulator according to the calculation result, so that the NULL, QUARD and other working points are stabilized in the set range.

[0004] At present, with the increasing application of coherent optical modules in data centers, the volume of the coherent optical module is reduced. This requires that the volume of the internal elements of the coherent optical module be minimized. However, in the current coherent optical module, the high gain detection circuit occupies a large area of the board, which is not conducive to the miniaturization of the coherent optical module. UTILITY MODEL CONTENTS

[0005] The embodiment of the utility model provides a micro motion signal detector and coherent optical module to improve the gain of the detection circuit in limited space.

[0006] In order to solve the above technical problems, the embodiment of the utility model discloses the following technical scheme:

[0007] A micro-motion signal detector is provided, comprising:

[0008] at least two parallel detection modules, each of the detection modules comprising a photodetector and a trans-impedance amplifier connected in sequence, the photodetector being configured to detect time-division transmitted micro-motion light signals and convert the micro-motion light signals into micro-motion current signals, the trans-impedance amplifier being configured to receive the micro-motion current signals and convert the micro-motion current signals into micro-motion voltage signals;

[0009] an isolation module having at least two input ends and an output end, the isolation module being configured to isolate direct current signals in the micro-motion voltage signals transmitted by the detection modules and output micro-motion voltage signals containing only alternating current signals, the at least two input ends being connected to the trans-impedance amplifiers one by one for receiving the micro-motion voltage signals output by the corresponding trans-impedance amplifiers, the micro-motion voltage signals including direct current signals and alternating current signals;

[0010] an amplification module connected to the output end of the isolation module, the amplification module being configured to receive the micro-motion voltage signals after the isolation processing and perform multi-stage amplification on the micro-motion voltage signals after the isolation processing.

[0011] In an embodiment, the isolation module comprises at least two parallel coupling capacitors, one end of each of the at least two parallel coupling capacitors being connected to the trans-impedance amplifiers in the at least two parallel detection modules, and the other end of each of the at least two parallel coupling capacitors being connected to the amplification module.

[0012] In an embodiment, the coupling capacitors have a capacitance ranging from 1 nF to 1 uF.

[0013] In an embodiment, the amplification module comprises a first power amplifier and a second power amplifier, an input end of the first power amplifier being coupled to an output end of the isolation module, an output end of the first power amplifier being configured to be coupled to an input end of the second power amplifier, and an output end of the second power amplifier being configured to output the micro-motion voltage signals after the multi-stage amplification.

[0014] In an embodiment, the amplification module further comprises at least one third power amplifier, the third power amplifier being connected between the output end of the first power amplifier and the input end of the second power amplifier.

[0015] In an embodiment, the plurality of power amplifiers included in the amplification module are integrated in the same chip.

[0016] In an embodiment, the micro-motion signal detector is connected between a microcontroller and a coherent modulator, and the plurality of power amplifiers included in the amplification module are integrated in the microcontroller.

[0017] In one embodiment, the amplification module further comprises an isolation capacitor, and two adjacent power amplifiers are coupled through the isolation capacitor.

[0018] The embodiment of the utility model provides a kind of coherent light module, including coherent modulator, microcontroller, bias signal controller, radio frequency amplifier and micro-motion signal detector;

[0019] The coherent modulator has a plurality of optical signal modulation channels.

[0020] The radio frequency amplifier is configured to transmit optical modulation information to the plurality of optical signal modulation channels.

[0021] The bias signal controller is configured to transmit a bias signal to the plurality of optical signal modulation channels, the bias signal is used to regulate the operating point of the optical signal modulation channel, and is also used to transmit a micro-motion optical signal to each channel of the coherent modulator in time sharing manner.

[0022] The micro-motion signal includes an isolation module, an amplification module and at least two parallel detection modules, each of the detection modules includes an optical detector and a transimpedance amplifier connected in sequence, the optical detector is configured to detect the micro-motion optical signal transmitted in time sharing manner and convert the micro-motion optical signal into a micro-motion current signal, and the transimpedance amplifier is configured to receive the micro-motion current signal and convert the micro-motion current signal into a micro-motion voltage signal; the isolation module has an output end and at least two input ends, the isolation module isolates the direct current signal in the micro-motion voltage signal transmitted by the detection module, and outputs the micro-motion voltage signal containing only alternating current signal, the at least two input ends are connected with the transimpedance amplifiers one by one, and are configured to receive the micro-motion voltage signal output by the corresponding transimpedance amplifier, the micro-motion voltage signal includes direct current signal and alternating current signal; the amplification module is connected with the output end of the isolation module, and is configured to receive the micro-motion voltage signal processed by isolation and amplify the micro-motion voltage signal processed by isolation in multiple stages; the microcontroller is configured to receive the micro-motion voltage signal amplified in multiple stages, and transmit an adjustment signal to the bias signal controller based on the micro-motion voltage signal amplified in multiple stages, and the bias signal controller adjusts the bias signal output based on the adjustment signal, so that the operating point of the optical signal modulation channel is stabilized around the set point.

[0023] In one embodiment, the amplification module comprises a first power amplifier and a second power amplifier, an input end of the first power amplifier is coupled with an output end of the isolation module, an output end of the first power amplifier is used for being coupled with an input end of the second power amplifier, and an output end of the second power amplifier is used for outputting the micro-motion voltage signal amplified by multiple stages, wherein the first power amplifier and the second power amplifier are integrated in the microcontroller.

[0024] One of the above technical solutions has the following advantages or beneficial effects: the micro-motion voltage signals output by different detection modules are input into the same amplification module for multi-stage amplification after being AC coupled by the isolation module. By arranging only one multi-stage amplification link, the amplitude of the micro-motion voltage signal output by each detection module is effectively enhanced, the response sensitivity of the system to the micro-motion light signal is improved, and the overall detection precision is improved; and the board area of the high-gain micro-motion signal detector is reduced, thereby helping to realize the miniaturization design of the coherent light module.

[0025] Further, when the photoelectric detector in the detection module converts the micro-motion light signal into a micro-motion current signal, in addition to capturing the AC component of the micro-motion light signal, it also responds to the low-frequency or steady-state component in the light signal. Therefore, after the micro-motion current signal is converted into a micro-motion voltage signal, the micro-motion voltage signal includes not only the AC signal representing the micro-motion light signal, but also a DC signal. When the micro-motion voltage signal is amplified by multiple stages, the DC signal will mask the AC signal, affecting the detection precision. Before the micro-motion voltage signal is amplified by multiple stages, the isolation module is used to remove the DC signal in the micro-motion voltage signal and only retain part of the AC signal, effectively avoiding the interference of the DC offset on the signal processing, and significantly improving the precision of the micro-motion light signal detection. BRIEF DESCRIPTION OF DRAWINGS

[0026] The technical solutions and other beneficial effects of the present application will become apparent from the following detailed description of the specific embodiments of the present application, combined with the accompanying drawings.

[0027] Figure 1 is a structural schematic diagram of a micro-motion signal detector provided by an embodiment of the present application;

[0028] Figure 2 is a structural schematic diagram of another micro-motion signal detector provided by an embodiment of the present application;

[0029] Figure 3 is an integrated schematic diagram of an amplification module provided by an embodiment of the present application;

[0030] Figure 4 is a structural schematic diagram of a coherent light module provided by an embodiment of the present application.

[0031] Explanation of reference numerals in the attached figures:

[0032] 10. Detection module;

[0033] 20. Isolation module;

[0034] 30. Amplification module;

[0035] 40. Coherent modulator; 401. Optical signal modulation channel; 4011. Signal output terminal;

[0036] 50. Microcontroller.

[0037] 60. Light source;

[0038] 70. Bias signal controller;

[0039] 80. Radio frequency amplifier;

[0040] 90. Data signal source;

[0041] 100. Micro-motion signal detector. Detailed Implementation

[0042] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are merely for explaining the present utility model and are not intended to limit the present utility model.

[0043] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0044] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] This utility model discloses a micro-motion signal detector. Embodiment one disclosed in this application is as follows... Figure 1As shown, the micro-motion signal detector 100 includes two parallel detection modules 10, an isolation module 20, and an amplification module 30. Each detection module 10 includes a photodetector MPD and a transimpedance amplifier TIA connected in sequence. The photodetector MPD is used to detect the time-division multiplexing micro-motion optical signal and convert it into a micro-motion current signal. The transimpedance amplifier TIA is used to receive the micro-motion current signal and convert it into a micro-motion voltage signal. Furthermore, when the photodetector MPD converts the micro-motion optical signal into a micro-motion current signal, in addition to capturing the AC component of the micro-motion optical signal, it also responds to the low-frequency or steady-state components in the optical signal. Therefore, when the micro-motion current signal is converted into a micro-motion voltage signal, the micro-motion voltage signal includes both the AC signal characterizing the micro-motion optical signal and the DC signal characterizing the low-frequency or steady-state components. The DC signal reflects the average light intensity in the micro-motion optical signal. If the micro-motion voltage signal containing both AC and DC signals is directly transmitted to the amplification module 30 for multi-stage amplification, the DC signal will mask the AC signal, affecting the detection accuracy. Therefore, this application provides an isolation module 20 between the detection module 10 and the amplification module 30. The isolation module 20 has an output terminal and two input terminals. The two input terminals are connected one-to-one with the transimpedance amplifiers (TIAs) in the two parallel detection modules 10, and are used to receive the micro-motion voltage signals output by the corresponding transimpedance amplifiers (TIAs). The isolation module 20 isolates the DC signal in the micro-motion voltage signal transmitted from the detection module 10, and outputs a micro-motion voltage signal containing only AC signal. The amplification module 30 is connected to the output terminal of the isolation module 20, receives the isolated micro-motion voltage signal, and performs multi-stage amplification on the isolated micro-motion voltage signal.

[0047] In this way, the micro-motion voltage signals output from different detection modules 10 are AC-coupled through the isolation module 20 and then input into the same amplification module 30 for multi-stage amplification in a time-division manner. By deploying only one multi-stage amplification link, the amplitude of the micro-motion voltage signal output by each detection module 10 is effectively increased, improving the system's response sensitivity to micro-motion optical signals and enhancing the overall detection accuracy. Simultaneously, the board area of ​​the high-gain micro-motion signal detector 100 is reduced, thus contributing to the miniaturization design of the coherent optical module. Furthermore, before multi-stage amplification of the micro-motion voltage signal, the isolation module 20 removes the DC signal from the micro-motion voltage signal, retaining only the AC signal portion. This effectively avoids the phenomenon of accumulated DC offset interfering with the detection of micro-motion optical signals when multiple detection modules 10 share a single multi-stage amplification link.

[0048] Specifically, the isolation module 20 includes two parallel coupling capacitors C0, each corresponding to a transgroup amplifier in one of the two parallel detection modules 10. One end of each coupling capacitor C0 is connected to the output of its corresponding transgroup amplifier, and the other end is connected to the amplification module 30. The capacitance value of the coupling capacitor C0 is between 1nF and 1uF. In practical applications, the selection of the capacitance value of the coupling capacitor C0 needs to consider the frequency of the micro-motion optical signal to be detected. Selecting a larger capacitance value for the coupling capacitor C0 (e.g., close to 1uF) is more suitable for processing lower frequency signals in the micro-motion optical signal; selecting a smaller capacitance value for the coupling capacitor C0 (e.g., close to 1nF) is more suitable for processing higher frequency signals in the micro-motion optical signal.

[0049] Continue to refer to Figure 1 In the first embodiment disclosed in this application, the amplification module 30 includes a first power amplifier PA1 and a second power amplifier PA2. The input terminal of the first power amplifier PA1 is coupled to the output terminal of the isolation module 20. The output terminal of the first power amplifier PA1 is used to couple to the input terminal of the second power amplifier PA2. The output terminal of the second power amplifier PA2 is used to output a micro-motion voltage signal amplified through multiple stages. Specifically, the output terminal of the first power amplifier PA1 and the input terminal of the second power amplifier PA2 can be directly connected, or they can be coupled through an isolation capacitor C1. Here, they are coupled through an isolation capacitor C1.

[0050] Furthermore, in some embodiments, the micro-motion signal detector 100 includes two or more detection modules 10, such as three or four. The two or more detection modules 10 are connected in parallel, and each detection module 10 includes a photodetector MPD and a transimpedance amplifier TIA connected in sequence. The MPD receives the time-division multiplexed micro-motion optical signal and converts it into a micro-motion current signal, which is then converted into a micro-motion voltage signal by the TIA. The corresponding isolation module 20 also includes two or more coupling capacitors C0. For example, when there are three detection modules 10, there are also three coupling capacitors C0. Each of the three coupling capacitors C0 corresponds to one of the three detection modules 10 to receive the time-division multiplexed micro-motion voltage signal output by the detection modules 10.

[0051] Embodiment two disclosed in this application is as follows: Figure 2 As shown, unlike Embodiment 1, the amplification module 30 further includes at least one third power amplifier PA3. The third power amplifier PA3 is coupled between the output terminal of the first power amplifier PA1 and the input terminal of the second power amplifier PA2. The first power amplifier PA1, the third power amplifier PA3, and the second power amplifier PA2 can be directly connected or coupled through an isolation capacitor C1. Here, they are coupled through an isolation capacitor C1.

[0052] It is worth mentioning that the amplification module 30 disclosed above has the following three integration methods. The first integration method is that the multiple power amplifiers included in the amplification module 30 (e.g., the first power amplifier PA1, the second power amplifier PA2, and the third power amplifier PA3) can be integrated into the same chip, and the integrated chip is installed in the micro-motion signal detector disclosed in this application. That is, the first power amplifier PA1, the second power amplifier PA2, and the isolation capacitor C1 disclosed in Embodiment 1 are integrated into the same chip; the first power amplifier PA1, the second power amplifier PA2, the third power amplifier PA3, and the isolation capacitor C1 disclosed in Embodiment 2 are integrated into the same chip. The second integration method is that the multiple power amplifiers included in the amplification module 30 and the isolation capacitor C1 are directly installed as components in the micro-motion signal detector disclosed in this application. The third integration method is that the isolation capacitor C1 is installed in the micro-motion signal detector 100 (refer to...). Figure 3 The power amplifiers (first power amplifier PA1 and second power amplifier PA2) reuse the power amplifiers in the microcontroller 50. Because the micro-motion detector 100 is typically used in coherent optical modules, in which the micro-motion detector 100 is connected between the microcontroller 50 and the coherent modulator 40 (see reference 100). Figure 4 Since the microcontroller 50 typically contains multiple power amplifiers, the power amplifiers in the microcontroller 50 can be reused. This arrangement can further reduce the board area of ​​the micro-motion signal detector. In actual connection, the capacitor pins of the micro-motion signal detector are connected to the amplifier pins in the microcontroller to form the aforementioned amplification module.

[0053] This utility model also discloses a coherent optical module. (Refer to...) Figure 4 The coherent optical module includes a coherent modulator 40, a microcontroller 50, a light source 60, a bias signal controller 70, an RF amplifier 80, and the micro-motion signal detector 100 disclosed above. The coherent modulator 40 has multiple optical signal modulation channels 401. The RF amplifier 80 receives modulation data from a data signal source 90 and transmits optical modulation information to the multiple optical signal modulation channels 401. The bias signal controller 70 transmits bias signals to the multiple optical signal modulation channels 401. The bias signals are used to adjust the operating point of the optical signal modulation channels 401. The bias signal controller 70 is also used to transmit micro-motion optical signals to each channel of the coherent modulator 40 in a time-division manner. The micro-motion signal detector 100 receives the micro-motion optical signals transmitted in a time-division manner through the optical signal modulation channels 401, converts the micro-motion optical signals into micro-motion voltage signals, and amplifies the micro-motion voltage signals in multiple stages.

[0054] Specifically, the micro-motion signal detector 100 includes an isolation module 20, an amplification module 30, and at least two parallel detection modules 10. The at least two parallel detection modules 10 correspond to different optical signal modulation channels 401 of the coherent modulator 40. The detection modules 10 are optically connected to the signal output terminals 4011 of the optical signal modulation channels 401. Micro-motion optical signals are output from the signal output terminals 4011 of the different optical signal modulation channels 401 of the coherent modulator 40 in a time-division manner, thereby enabling different detection modules 10 to sequentially detect the micro-motion optical signals output by their corresponding channels at different time periods.

[0055] Each detection module 10 includes a photodetector (MPD) and a transimpedance amplifier (TIA) connected in sequence. The MPD detects the time-division multiplexed micro-motion signal and converts it into a micro-motion current signal. The TIA receives the micro-motion current signal and converts it into a micro-motion voltage signal. An isolation module 20 has an output terminal and at least two input terminals. The isolation module 20 isolates the DC signal in the micro-motion voltage signal transmitted from the detection module 10, outputting a micro-motion voltage signal containing only AC signals. The two input terminals of the isolation module 20 are connected one-to-one with the transimpedance amplifiers (TIAs) to receive the corresponding micro-motion voltage signals output by the TIAs. The micro-motion voltage signals include both DC and AC signals. An amplification module 30 is connected to the output terminal of the isolation module 20. The amplification module 30 receives the isolated micro-motion voltage signals and amplifies them in multiple stages.

[0056] The microcontroller 50 receives the multi-stage amplified micro-motion voltage signal and transmits an adjustment signal to the bias signal controller 70 based on the multi-stage amplified micro-motion voltage signal. The bias signal controller 70 adjusts the output bias signal based on the adjustment signal to stabilize the operating point of the optical signal modulation channel 401 near the set point. It should be noted that the multi-stage amplified micro-motion voltage signal is typically transmitted in the digital-to-analog converter (ADC) of the microcontroller 50.

[0057] The specific structure and connection relationship of each module of the micro-motion signal detector 100 in the coherent optical module have been disclosed in detail above, and will not be repeated here.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A micro-motion signal detector, characterized in that, include: At least two parallel detection modules are provided, each of which includes a photodetector and a transimpedance amplifier connected in sequence. The photodetector is used to detect the time-division transmitted micro-motion optical signal and convert the micro-motion optical signal into a micro-motion current signal. The transimpedance amplifier is used to receive the micro-motion current signal and convert the micro-motion current signal into a micro-motion voltage signal. An isolation module has an output terminal and at least two input terminals. The isolation module isolates the DC signal in the micro-motion voltage signal transmitted from the detection module and outputs a micro-motion voltage signal containing only AC signal. The at least two input terminals are connected one-to-one with the transimpedance amplifier to receive the corresponding micro-motion voltage signal output by the transimpedance amplifier. The micro-motion voltage signal includes both DC and AC signals. An amplification module is connected to the output of the isolation module. The amplification module is used to receive the isolated micro-motion voltage signal and amplify the isolated micro-motion voltage signal in multiple stages.

2. The micro-motion signal detector according to claim 1, characterized in that... The isolation module includes at least two parallel coupling capacitors, one end of which is connected to the transimpedance amplifier in at least two parallel detection modules, and the other end of which is connected to the amplification module.

3. The micro-motion signal detector according to claim 2, characterized in that, The capacitance range of the coupling capacitor is 1nf-1uf.

4. The micro-motion signal detector according to claim 1, characterized in that, The amplification module includes a first power amplifier and a second power amplifier. The input terminal of the first power amplifier is coupled to the output terminal of the isolation module. The output terminal of the first power amplifier is used to be coupled to the input terminal of the second power amplifier. The output terminal of the second power amplifier is used to output a micro-motion voltage signal that has been amplified through multiple stages.

5. The micro-motion signal detector according to claim 4, characterized in that, The amplification module further includes at least one third power amplifier, which is connected between the output of the first power amplifier and the input of the second power amplifier.

6. The micro-motion signal detector according to claim 4 or 5, characterized in that, The amplification module includes multiple power amplifiers integrated into the same chip.

7. The micro-motion signal detector according to claim 4 or 5, characterized in that, The micro-motion signal detector is connected between the microcontroller and the coherent modulator, and the multiple power amplifiers included in the amplification module are integrated into the microcontroller.

8. The micro-motion signal detector according to claim 4 or 5, characterized in that, The amplification module also includes an isolation capacitor, through which two adjacent power amplifiers are coupled.

9. A coherent optical module, characterized in that, This includes a coherent modulator, microcontroller, bias signal controller, RF amplifier, and micro-motion signal detector; The coherent modulator has multiple optical signal modulation channels; The radio frequency amplifier is used to transmit optical modulation information to the plurality of optical signal modulation channels; The bias signal controller is used to transmit bias signals to the plurality of optical signal modulation channels. The bias signals are used to adjust the operating point of the optical signal modulation channels. The bias signal controller is also used to transmit micro-motion optical signals to each channel of the coherent modulator in a time-division manner. The micro-motion signal detector includes an isolation module, an amplification module, and at least two parallel detection modules. Each detection module includes a photodetector and a transimpedance amplifier connected in sequence. The photodetector is used to detect the time-division multiplexing micro-motion optical signal and convert the micro-motion optical signal into a micro-motion current signal. The transimpedance amplifier is used to receive the micro-motion current signal and convert the micro-motion current signal into a micro-motion voltage signal. The isolation module has an output terminal and at least two input terminals. The isolation module isolates the DC signal in the micro-motion voltage signal transmitted from the detection module and outputs a micro-motion voltage signal containing only AC signal. The at least two input terminals are connected one-to-one with the transimpedance amplifiers to receive the corresponding micro-motion voltage signal output by the transimpedance amplifier. The micro-motion voltage signal includes both DC and AC signals. The amplification module is connected to the output terminal of the isolation module. The amplification module is used to receive the isolated micro-motion voltage signal and amplify the isolated micro-motion voltage signal in multiple stages. The microcontroller is used to receive a micro-motion voltage signal that has been amplified through multiple stages, and to transmit an adjustment signal to the bias signal controller based on the amplified micro-motion voltage signal. The bias signal controller adjusts the output bias signal based on the adjustment signal so that the operating point of the optical signal modulation channel is stabilized near the set point.

10. The coherent optical module according to claim 9, wherein the amplification module includes a first power amplifier and a second power amplifier, the input terminal of the first power amplifier is coupled to the output terminal of the isolation module, the output terminal of the first power amplifier is used to be coupled to the input terminal of the second power amplifier, and the output terminal of the second power amplifier is used to output a micro-motion voltage signal amplified through multiple stages. in, The first power amplifier and the second power amplifier are integrated in the microcontroller.

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