Signal monitoring method and apparatus applicable to electro-optic modulators, and electronic devices

Abstract

This disclosure provides a signal monitoring method and apparatus, electronic devices, computer-readable storage media, and computer program products applicable to an electro-optic modulator. The signal monitoring method includes inputting a modulated voltage signal to the modulation circuit of an electro-optic modulator, the modulated voltage signal being obtained by superimposing a carrier voltage signal and a pulse voltage signal, wherein the amplitude of the carrier voltage signal is greater than the half-wavelength voltage Vpi of the electro-optic modulator and the amplitude of the pulse voltage signal is less than the peak-to-peak value Vpp of the carrier voltage signal; obtaining a photoelectric conversion detection signal corresponding to the output optical signal of the electro-optic modulator; and monitoring the presence of the pulse voltage signal in the modulated voltage signal based on the photoelectric conversion detection signal.

Description

Technical Field

[0001] Cross - reference to Related Patent Applications This disclosure claims the priority of Chinese Patent Application No. 2023108286133, filed on July 6, 2023, which is incorporated herein by reference in its entirety. This disclosure relates to the technical field of optical communication, and in particular, to a signal monitoring method and apparatus, an electronic device, a computer - readable storage medium, and a computer program product applied to an electro - optical modulator.

Background Art

[0002] In recent years, with the rapid development of new network application services such as the Internet of Things, driverless, telemedicine, and distance education, higher requirements have been imposed on high - speed and large - capacity communication technologies. Optical communication has achieved rapid development in the trend of high - speed and large - capacity communication due to its characteristics such as wide bandwidth, high reliability, low cost, and strong anti - interference ability. The method of loading high - speed electrical signals onto optical carriers is a core research content.

[0003] An electro - optical modulator is a modulator made based on the electro - optical effect of electro - optical materials. The electro - optical effect means that when a voltage is applied to an electro - optical material such as a lithium niobate crystal, a gallium arsenide crystal, or a lithium tantalate crystal, the refractive index of the electro - optical material changes, resulting in a change in the characteristics of the light wave passing through the electro - optical material. The use of the electro - optical effect enables the modulation of parameters such as the phase, amplitude, intensity, and polarization state of an optical signal.

[0004] As the requirements for high - speed and large - capacity communication technologies become increasingly urgent, higher requirements have been imposed on the monitoring of the operating signals of electro - optical modulators.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Embodiments of this disclosure provide signal monitoring methods and apparatus, electronic devices, computer-readable storage media, and computer program products applicable to electro-optic modulators for effective and simplified monitoring of the operating signals of the electro-optic modulators. [Means for solving the problem]

[0006] According to one aspect of this disclosure, a signal monitoring method applicable to an electro-optic modulator is provided. The method is: This involves inputting a modulated voltage signal to the modulation circuit of an electro-optic modulator, wherein the modulated voltage signal is obtained by superimposing a carrier voltage signal and a pulse voltage signal, and the amplitude of the carrier voltage signal is greater than the half-wavelength voltage Vpi of the electro-optic modulator, and the amplitude of the pulse voltage signal is less than the peak-to-peak value Vpp of the carrier voltage signal. To acquire a photoelectric conversion detection signal corresponding to the output optical signal of an electro-optic modulator, To monitor the presence of a pulse voltage signal in a modulated voltage signal based on a photoelectric conversion detection signal. Includes.

[0007] According to one aspect of this disclosure, a signal monitoring device applicable to an electro-optic modulator is provided. The device is An input unit configured to input a modulated voltage signal to the modulation circuit of an electro-optic modulator, wherein the modulated voltage signal is obtained by superimposing a carrier voltage signal and a pulse voltage signal, and the amplitude of the carrier voltage signal is greater than the half-wavelength voltage Vpi of the electro-optic modulator, and the amplitude of the pulse voltage signal is less than the peak-to-peak value Vpp of the carrier voltage signal, An acquisition unit configured to acquire a photoelectric conversion detection signal corresponding to the output optical signal of an electro-optic modulator, A monitoring unit configured to monitor the presence of a pulse voltage signal in a modulated voltage signal based on a photoelectric conversion detection signal, Includes.

[0008] According to one aspect of the present disclosure, an electronic device is provided comprising at least one processor and a memory communicably connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and when executed by the at least one processor, the instructions cause the at least one processor to perform the signal monitoring method described in the above-described aspect.

[0009] According to one aspect of the present disclosure, a computer-readable storage medium for storing computer instructions is provided, the computer instructions are configured to cause a computer to perform the signal monitoring method described in the preceding embodiment. According to one aspect of the present disclosure, a computer program product including a computer program is provided, and when the computer program is executed by a processor, the signal monitoring method described in the above-described embodiment is performed.

[0010] According to one or more embodiments of the present disclosure, the operating signals of an electro-optic modulator can be efficiently monitored. Furthermore, there is no need to provide additional bias voltage modulation circuits and associated signal inputs, which enables simplified monitoring logic and implementation, and thus reduces development costs.

[0011] It should be understood that the information described in this section is not intended to identify any defining or essential features of the embodiments of the Disclosure, nor is it intended to limit the scope of the Disclosure. Other features of the Disclosure will be readily apparent from the following description.

[0012] Further details, features, and advantages of this disclosure are disclosed in the following description of exemplary embodiments with reference to the accompanying drawings. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of the structure of a conventional Mach-Zehnder modulator. [Figure 2]This is a schematic diagram of the structure of an electro-optic modulator according to some embodiments of the present disclosure. [Figure 3] This is a schematic flowchart of a signal monitoring method applied to an electro-optic modulator according to some embodiments of the present disclosure. [Figure 4] These are schematic diagrams of pulse voltage signals, carrier voltage signals, modulated voltage signals, and photoelectric conversion detection signals according to some embodiments of the present disclosure. [Figure 5] This is a block diagram of the structure of a signal monitoring device applied to an electro-optic modulator according to some embodiments of the present disclosure. [Modes for carrying out the invention]

[0014] Exemplary embodiments of this disclosure are described below in conjunction with the accompanying drawings, and various details of the embodiments of this disclosure are included for the purpose of facilitating understanding and should be considered merely illustrative. Accordingly, those skilled in the art should be aware that various changes and modifications can be made to the embodiments described herein without departing from the scope of this disclosure. Similarly, for clarity and brevity, well-known functional and structural descriptions are omitted in the following description.

[0015] Unless otherwise stated in this disclosure, terms such as “first,” “second,” etc., used to describe various elements are not intended to limit the spatial, temporal, or significance of those elements, but only to distinguish one element from another. In some instances, the first and second elements may refer to the same example of an element, and in some instances, the first and second elements may refer to different examples based on contextual descriptions.

[0016] The terms used in the description of various examples in this disclosure are for the purpose of describing a particular example only and are not intended to be limiting. If the number of elements is not specifically defined, one or more elements may be present unless explicitly indicated otherwise in the context. Further, the term "and / or" used in this disclosure encompasses any and all possible combinations of the recited terms.

[0017] A Mach-Zehnder modulator is a type of electro-optic modulator in which an input optical signal is evenly split into two branched optical signals, which then enter two waveguide arms respectively. The two waveguide arms are each made of an electro-optic material and have a refractive index that changes with an applied modulation voltage. A change in the refractive index of the waveguide arm may result in a change in the phase of the branched optical signal. Therefore, the output from the convergence of the two branched optical signals is an interference signal having an intensity that changes with the modulation voltage. Briefly speaking, a Mach-Zehnder modulator can perform modulation of various sidebands by controlling the modulation voltage applied to the two waveguide arms. As a device for converting an electrical signal into an optical signal, a Mach-Zehnder modulator is one of the common core devices in optical interconnection systems, optical computing systems, and optical communication systems.

[0018] FIG. 1 shows a schematic structural diagram of a conventional Mach-Zehnder modulator. Ideally, the Mach-Zehnder modulator 001 has two waveguide arms 02 that are identical to each other. When the Mach-Zehnder modulator 001 is not operating, neither of the two waveguide arms 02 is subject to the electro-optic effect. An input light beam passes through the beam splitting element 01 and is then evenly split into two branched optical signals. The two branched optical signals are in the same phase even after each passes through one of the waveguide arms 02, and then a coherently enhanced signal for the two branched optical signals is output from the beam combining element 05. When the Mach-Zehnder modulator 001 is operating, a radio frequency modulation circuit 04 (for example, including a radio frequency signal electrode 042, a first ground electrode 041, and a second ground electrode 042) applies a modulation voltage to the two waveguide arms 02, and the two branched optical signals can have a phase difference that is an odd or even multiple of Π after each passes through one of the waveguide arms 02. When the two branched optical signals have a phase difference that is an even multiple of Π, the beam combining element 05 outputs a coherently enhanced signal for the two branched optical signals. When the two branched optical signals have a phase difference that is an odd multiple of Π, the beam combining element 05 outputs a coherent cancellation signal for the two branched optical signals.

[0019] However, in reality, the two waveguide arms 02 cannot be completely identical due to reasons such as materials and charge accumulation. When the Mach-Zehnder modulator 001 is not operating, some phase shift appears after the two branched optical signals each pass through one of the waveguide arms 02. This phase shift is inevitable, is an inherent phase difference, and may change with changes in time and environmental conditions. The existence of this phase shift affects the accuracy of the output signal when the Mach-Zehnder modulator 001 is operating, or even makes it impossible for the Mach-Zehnder modulator 001 to perform normal output.

[0020] Therefore, as shown in Figure 1, a bias voltage modulation circuit 03 (for example, including a bias voltage signal electrode 032, a third ground electrode 031, and a fourth ground electrode 033) is generally required to perform bias voltage modulation on the two waveguide arms 02 and to compensate for the phase shift caused by the inherent difference between the two waveguide arms 02.

[0021] In the case of a Mach-Zehnder modulator, if the Mach-Zehnder modulator has an operating point that is not midway between the highest and lowest light passing power (meaning the light output point under the control of an electrical signal, the parameters of which are usually adjusted to obtain the appropriate operating point), its electrical-to-optical conversion efficiency will be low. Conversely, if the Mach-Zehnder modulator has an operating point at either the highest or lowest light passing power, its electrical-to-optical conversion efficiency will be zero.

[0022] Therefore, in related technologies, as shown in Figure 1, a photoelectron sensor 06 is commonly used to monitor the output optical signal of the Mach-Zehnder modulator 001, and then adjusts the bias voltage signal output to the bias voltage modulation circuit 03 based on feedback of the monitoring information to achieve accurate bias voltage modulation. However, this monitoring method complicates the system and leads to increased system costs.

[0023] Embodiments of this disclosure provide signal monitoring methods and apparatus, electronic devices, computer-readable storage media, and computer program products applicable to electro-optic modulators for efficient and simplified monitoring of the operating signals of the electro-optic modulators.

[0024] Figure 2 may be referenced for the structure of an electro-optic modulator, which includes a ray splitting element 10, a ray coupling element 50, two waveguide arms 20, a modulation circuit 40, and a photoelectron sensor 60.

[0025] As shown in Figures 3 and 4, a signal monitoring method 300 applied to an electro-optic modulator according to some embodiments of the present disclosure includes the following steps S301 to S303.

[0026] In step S301, a modulated voltage signal is input to the modulation circuit of the electro-optic modulator, and the modulated voltage signal is obtained by superimposing a carrier voltage signal and a pulse voltage signal, where the amplitude of the carrier voltage signal is greater than the half-wavelength voltage Vpi of the electro-optic modulator, and the amplitude of the pulse voltage signal is less than the peak-to-peak value Vpp of the carrier voltage signal.

[0027] The adjustment circuit includes several electrodes (such as a first ground electrode 401, a signal electrode 402, and a second ground electrode 403, as shown in Figure 2), and its specific arrangement is not limited. For example, arrangements such as GSG, GSGSG, etc., may be used, in which case G represents a ground electrode and S represents a signal electrode, and is configured to receive a modulated voltage signal.

[0028] The carrier voltage signal functions as a bias voltage signal, and its amplitude should be greater than the half-wavelength voltage Vpi of the electro-optic modulator, which is the voltage value required by the electro-optic modulator to produce a half-wavelength phase shift of the output signal. The carrier voltage signal is a signal with a continuously changing voltage. For example, a sinusoidal voltage signal or a triangular wave voltage signal may be used.

[0029] The amplitude of the pulsed voltage signal is less than the peak-to-peak value Vpp of the carrier voltage signal, so that the carrier voltage signal can be superimposed on the pulsed voltage signal to obtain a modulated voltage signal with carrier wave and small pulse characteristics.

[0030] The modulated voltage signal is input to the modulation circuit, and the carrier voltage signal in the modulation circuit is equivalent to the bias voltage signal. The voltage of the carrier voltage signal is continuously changing, which corresponds to the fact that the bias voltage at the operating point of the electro-optic modulator is constantly changing.

[0031] In step S302, a photoelectric conversion detection signal corresponding to the output optical signal of the electro-optic modulator is acquired. The photoelectric conversion detection signal corresponding to the output optical signal may be acquired by detecting the output optical signal with a photoelectron sensor.

[0032] In step S303, the presence of a pulse voltage signal in the modulated voltage signal is monitored based on the photoelectric conversion detection signal.

[0033] Due to the relatively small size and weak amplitude of pulsed voltage signals, it is impossible to accurately monitor at the input side whether a pulsed voltage signal is actually present in the modulated voltage signal input to the modulation circuit. In embodiments of this disclosure, a photoelectron sensor is used to monitor the output optical signal of an electro-optic modulator and to obtain a photoelectric conversion detection signal. Since the photoelectric conversion detection signal has a period and amplitude significantly larger than that of the modulated voltage signal, it is possible to accurately monitor the presence of a pulsed voltage signal in the modulated voltage signal.

[0034] As shown in Figure 4, within the period of the photoelectric conversion detection signal, the pulse voltage signal receives a response during some periods and not during others. This means that the pulse voltage signal always receives a sufficient response in each period regardless of the position of the operating point of the electro-optic modulator, and as a result, it is possible to monitor the presence of the pulse voltage signal in the modulated voltage signal. Therefore, the operating signal of the electro-optic modulator can be efficiently monitored in the signal monitoring method of this disclosure. Furthermore, there is no need to provide an additional bias voltage modulation circuit and associated signal inputs, which enables simplified monitoring logic and implementation, and therefore reduces development costs.

[0035] In some embodiments of this disclosure, step S303 specifically means: In response to the determination that the photoelectric conversion detection signal includes a first characteristic signal corresponding to the carrier voltage signal and a second characteristic signal corresponding to the pulse voltage signal, it is determined that the pulse voltage signal is present in the modulated voltage signal, In response to the determination that the photoelectric conversion detection signal includes a first characteristic signal corresponding to the carrier voltage signal and does not include a second characteristic signal corresponding to the pulse voltage signal, it is determined that the pulse voltage signal is not present in the modulated voltage signal. It may include.

[0036] Since the pulse voltage signal can receive a sufficient response in each period, it is possible to monitor the presence of the pulse voltage signal in the modulated voltage signal based on the logic described above.

[0037] In some embodiments of this disclosure, the signal monitoring method further includes determining the amplitude of a pulsed voltage signal based on a photoelectric conversion detection signal.

[0038] In this embodiment, the amplitude parameter of the pulse voltage signal can be determined based on the photoelectric conversion detection signal.

[0039] In a photoelectron sensor, Vpi = V1 / N and V2 = V1 * (V2' / (N * V1'))=VPI * (V2' / V1'). Therefore, the amplitude of the pulse voltage signal is given by the functional relationship V2=Vpi * It may also be determined based on (V2' / V1'), where V1 is the amplitude of the carrier voltage signal, V2 is the amplitude of the pulse voltage signal, Vpi is the half-wavelength voltage of the electro-optic modulator, V1' is the amplitude of the first characteristic signal in the photoelectric conversion detection signal, and V2' is the amplitude of the second characteristic signal in the photoelectric conversion detection signal.

[0040] In this embodiment, the amplitude of the pulse voltage signal can be obtained so that the modulated voltage signal input to the modulation circuit of the electro-optic modulator can be analyzed and adjusted.

[0041] In some embodiments of the present disclosure, the electro-optic modulator is a Mach-Zehnder electro-optic modulator having two waveguide arms, which may or may not be of equal length. For example, in some embodiments, the electro-optic modulator may be a Mach-Zehnder electro-optic modulator with non-equal arms.

[0042] Based on the same inventive concept, as shown in Figure 5, one embodiment of the present disclosure further provides a signal monitoring device 500 applied to an electro-optic modulator. This device is An input unit 501 configured to input a modulated voltage signal to the modulation circuit of an electro-optic modulator, wherein the modulated voltage signal is obtained by superimposing a carrier voltage signal and a pulse voltage signal, and the amplitude of the carrier voltage signal is greater than the half-wavelength voltage Vpi of the electro-optic modulator, and the amplitude of the pulse voltage signal is less than the peak-to-peak value Vpp of the carrier voltage signal, An acquisition unit 502 configured to acquire a photoelectric conversion detection signal corresponding to the output optical signal of an electro-optic modulator, A monitoring unit 503 is configured to monitor the presence of a pulse voltage signal in a modulated voltage signal based on a photoelectric conversion detection signal. Includes.

[0043] In some embodiments, the monitoring unit 503 is configured to determine that a pulse voltage signal is present in the modulated voltage signal in response to a determination that the photoelectric conversion detection signal includes a first characteristic signal corresponding to a carrier voltage signal and a second characteristic signal corresponding to a pulse voltage signal, and to determine that a pulse voltage signal is not present in the modulated voltage signal in response to a determination that the photoelectric conversion detection signal includes a first characteristic signal corresponding to a carrier voltage signal and does not include a second characteristic signal corresponding to a pulse voltage signal.

[0044] In some embodiments, the signal monitoring device 500 further includes a determination unit (not shown in the figure) configured to determine the amplitude of a pulse voltage signal based on a photoelectric conversion detection signal.

[0045] In some embodiments, the decision unit is related to the functional relation V2 = Vpi. * The system is configured to determine the amplitude of a pulsed voltage signal based on (V2' / V1'), where V2 is the amplitude of the pulsed voltage signal, Vpi is the half-wavelength voltage of the electro-optic modulator, V1' is the amplitude of the first characteristic signal, and V2' is the amplitude of the second characteristic signal.

[0046] In the signal monitoring device 500 of this disclosure, the operating signals of an electro-optic modulator can be efficiently monitored. Furthermore, there is no need to provide additional bias voltage modulation circuits and associated signal inputs, which enables simplified monitoring logic and implementation, and therefore reduces development costs.

[0047] According to one aspect of the present disclosure, an electronic device is further provided comprising at least one processor and a memory communicably connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and when executed by the at least one processor, the instructions cause the at least one processor to perform the signal monitoring method described in the above embodiments.

[0048] Electronic devices can work in conjunction with photoelectronic sensors to efficiently monitor the operating signals of electro-optic modulators. Furthermore, the elimination of the need for additional bias voltage modulation circuits and associated signal inputs allows for simplified monitoring logic and implementation, thus reducing development costs.

[0049] One embodiment of the present disclosure further provides a computer-readable storage medium for storing computer instructions, the computer instructions configured to cause a computer to perform steps of the method described in any one of the above embodiments.

[0050] In addition, one embodiment of the present disclosure further provides a computer program product including a computer program, wherein when the computer program is executed by a processor, the steps of the method described in any one of the above embodiments are performed.

[0051] Various embodiments of the systems and technologies described herein may be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standards products (ASSPs), system-on-chip (SOC) systems, composite programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementation in one or more computer programs, which may run and / or be interpreted on a programmable system including at least one programmable processor. The programmable processor may be a dedicated or general-purpose programmable processor capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, at least one input device, and at least one output device.

[0052] The program code used to carry out the methods of this disclosure may be written in any combination of one or more programming languages. Such program code may be provided for the processor or control unit of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the program code is executed by the processor or control unit, the functions / operations specified in the flowcharts and / or block diagrams are performed. The program code may run entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0053] In the context of this disclosure, a machine-readable medium may be a tangible medium which may contain or store a program for use by an instruction execution system, apparatus, or device, or for use in combination with an instruction execution system, apparatus, or device. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific examples of machine-readable storage media may include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any appropriate combination thereof.

[0054] To provide user interaction, the systems and techniques described herein may be implemented on a computer having a display device (e.g., a cathode ray tube (CRT) or liquid crystal display (LCD) monitor) configured to display information to the user, and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices may also be used to provide user interaction; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback), and the input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0055] The systems and technologies described herein may be implemented in computing systems including backend components (e.g., data servers), computing systems including middleware components (e.g., application servers), computing systems including frontend components (e.g., user computers including a graphical user interface or web browser through which a user can interact with the implementation of the systems and technologies described herein), or computing systems including any combination of backend components, middleware components, or frontend components. The components of the system may be connected to one another through digital data communication (e.g., communication networks) in any form or medium. Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the internet.

[0056] A computer system may include clients and servers. Clients and servers are generally geographically distant from each other and typically interact through a communication network. The relationship between the client and server is established by computer programs running on each computer that have a client-server relationship with each other. A server may be a cloud server, a server in a distributed system, or a server combined with a blockchain.

[0057] It should be understood that the steps may be rearranged, added, or deleted based on various forms of the procedures shown above. For example, the steps described herein may be performed simultaneously, sequentially, or in different orders, as long as the desired results of the technical solutions disclosed herein can be obtained.

[0058] While embodiments or examples of the present disclosure have been described with reference to the accompanying drawings, it should be recognized that the above-described methods, apparatus, and devices are merely illustrative embodiments or examples, and the scope of the present invention is defined not by embodiments or examples, but only by the granted claims and their equivalents. Various elements in embodiments or examples may be omitted or replaced by equivalent elements. Furthermore, the steps may be performed in an order different from that described herein. Furthermore, various elements in embodiments or examples may be combined in various ways. It is important to note that as the technology develops, many elements described herein may be replaced by equivalent elements appearing later in this disclosure.

Claims

1. A signal monitoring method applicable to an electro-optic modulator, The method involves inputting a modulated voltage signal to the modulation circuit of the electro-optic modulator, wherein the modulated voltage signal is obtained by superimposing a carrier voltage signal and a pulse voltage signal, and the amplitude of the carrier voltage signal is greater than the half-wavelength voltage Vpi of the electro-optic modulator, and the amplitude of the pulse voltage signal is less than the peak-to-peak value Vpp of the carrier voltage signal. To acquire a photoelectric conversion detection signal corresponding to the output optical signal of the aforementioned electro-optic modulator, The presence of the pulse voltage signal in the modulated voltage signal is monitored based on the photoelectric conversion detection signal. A signal monitoring method, including the following.

2. Based on the photoelectric conversion detection signal, monitoring the presence of the pulse voltage signal in the modulated voltage signal is performed. In response to the determination that the photoelectric conversion detection signal includes a first characteristic signal corresponding to the carrier voltage signal and a second characteristic signal corresponding to the pulse voltage signal, it is determined that the pulse voltage signal is present in the modulated voltage signal. In response to the determination that the photoelectric conversion detection signal includes the first characteristic signal corresponding to the carrier voltage signal and does not include the second characteristic signal corresponding to the pulse voltage signal, it is determined that the pulse voltage signal is not present in the modulated voltage signal. The signal monitoring method according to claim 1, including the method described in claim 1.

3. The amplitude of the pulse voltage signal is determined based on the photoelectric conversion detection signal. The signal monitoring method according to claim 2, further comprising:

4. The amplitude of the pulse voltage signal is determined based on the photoelectric conversion detection signal. Functional relationship V² = Vpi ＊ Determining the amplitude of the pulse voltage signal based on (V2' / V1'), wherein V2 is the amplitude of the pulse voltage signal, Vpi is the half-wavelength voltage of the electro-optic modulator, V1' is the amplitude of the first characteristic signal, and V2' is the amplitude of the second characteristic signal. The signal monitoring method according to claim 3, including the method described in claim 3.

5. The carrier voltage signal is a sinusoidal voltage signal or a triangular wave voltage signal. The signal monitoring method according to any one of claims 1 to 4.

6. A signal monitoring device applied to an electro-optic modulator, An input unit configured to input a modulated voltage signal to the modulation circuit of the electro-optic modulator, wherein the modulated voltage signal is obtained by superimposing a carrier voltage signal and a pulse voltage signal, and the amplitude of the carrier voltage signal is greater than the half-wavelength voltage Vpi of the electro-optic modulator, and the amplitude of the pulse voltage signal is less than the peak-to-peak value Vpp of the carrier voltage signal, An acquisition unit configured to acquire a photoelectric conversion detection signal corresponding to the output optical signal of the electro-optic modulator, A monitoring unit configured to monitor the presence of the pulse voltage signal in the modulated voltage signal based on the photoelectric conversion detection signal. A signal monitoring device equipped with the following features.

7. The monitoring unit, in response to determining that the photoelectric conversion detection signal includes a first characteristic signal corresponding to the carrier voltage signal and a second characteristic signal corresponding to the pulse voltage signal, determines that the pulse voltage signal is present in the modulated voltage signal, and The system is configured such that, in response to the determination that the photoelectric conversion detection signal includes the first characteristic signal corresponding to the carrier voltage signal and does not include the second characteristic signal corresponding to the pulse voltage signal, it is determined that the pulse voltage signal is not present in the modulated voltage signal. The signal monitoring device according to claim 6.

8. A determination unit configured to determine the amplitude of the pulse voltage signal based on the photoelectric conversion detection signal. The signal monitoring device according to claim 7, further comprising:

9. The aforementioned decision unit determines the functional relationship V2 = Vpi ＊ The amplitude of the pulse voltage signal is determined based on (V2' / V1'), where V2 is the amplitude of the pulse voltage signal, Vpi is the half-wavelength voltage of the electro-optic modulator, V1' is the amplitude of the first characteristic signal, and V2' is the amplitude of the second characteristic signal. The signal monitoring device according to claim 8.

10. At least one processor, A memory that is communicably connected to at least one of the processors, An electronic device having, An electronic device in which the memory stores instructions that can be executed by the at least one processor, and when the instructions are executed by the at least one processor, the instructions cause the at least one processor to perform the signal monitoring method described in any one of claims 1 to 5.

11. A computer-readable storage medium for storing computer instructions, wherein the computer instructions are configured to cause a computer to perform the signal monitoring method described in any one of claims 1 to 5.

12. A computer program product comprising a computer program, wherein when the computer program is executed by a processor, the signal monitoring method described in any one of claims 1 to 5 is performed.

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