Automatic testing device and method for high-frequency characteristics of high-speed electro-optical phase modulator

Abstract

The present application provides an automated testing device and method for the high-frequency characteristics of a high-speed electro-optical phase modulator, which belongs to the field of high-speed electro-optical phase modulator testing devices. The device controls a radio frequency signal generating module through a control processing module to send radio frequency signals of different frequencies and peak-to-peak values ​​to the electro-optical phase modulator to be tested. The control processing module obtains a power value measured by a power meter, and calculates the half-wave voltage of the electro-optical phase modulator to be tested through the power value, thereby achieving the effect of automated detection of the high-frequency characteristics of the electro-optical phase modulator to be tested. The automated detection device disclosed in the present application is not only simple and reliable in structure, but also easy to operate. In addition, the automated detection device can also perform real-time measurement and stability monitoring of the half-wave voltage of the high-speed electro-optical phase modulator, so as to achieve the technical effect of further expanding the use scenarios of the automated testing device.

Description

Technical Field

[0001] The present application relates to the technical field of high-speed electro-optical phase modulator test devices, and in particular to a high-speed electro-optical phase modulator high-frequency characteristic automatic test device and method. Background Art

[0002] Phase modulators are widely used in important fields such as fiber lasers and optical communication systems. Typical application scenarios include using phase modulators to broaden the spectrum to suppress nonlinear effects in fiber laser systems, compressing phase modulation chirps through dispersion devices to obtain pulse signals, using phase modulators in optical communications to form hexadecimal quadrature amplitude modulation (16-QAM) optical transmitters and optical code division multiple access (OCDMA) systems, and generating continuously adjustable millimeter wave signals. With the development of technology in this field, the performance requirements for phase modulators are becoming higher and higher. The half-wave voltage and its frequency response curve are one of the most important performance parameters of the phase modulator, especially for high-speed phase modulators. The measurement of its half-wave voltage and frequency response curve is even more important.

[0003] At present, the measurement methods of the half-wave voltage of the phase modulator include spectrum analysis, FM-IM conversion, optical heterodyne, etc. The spectrum analysis method obtains the half-wave voltage by measuring the intensity information of the spectral sideband after phase modulation; the FM-IM conversion method converts the phase modulation signal into an intensity modulation signal, and obtains the half-wave voltage by measuring the spectrum of the intensity modulation signal; the optical heterodyne method uses a spectrum analyzer and a photodetector to measure the difference frequency signal between the modulated light and the frequency-shifted light to obtain the half-wave voltage. The test accuracy of the spectrum analysis method is limited by the measurement accuracy of the spectrum measurement device / equipment, and the cost is often high. However, the FM-IM conversion method and the optical heterodyne method have complex systems and cumbersome operations, and it is difficult to achieve reliable automated measurement. Therefore, there is an urgent need for a new type of high-speed electro-optical phase modulator high-frequency characteristics automated test device and method, so as to realize the automated measurement of the half-wave voltage of the high-speed electro-optical phase modulator. Summary of the invention

[0004] In view of the technical problems existing in the background technology, the present application provides a device and method for automatically testing the high-frequency characteristics of a high-speed electro-optical phase modulator. The device and method can automatically test the high-frequency characteristics of the electro-optical phase modulator to be tested through an automated detection device. The structure is not only simple and reliable, but also easy to operate. Secondly, the above-mentioned automated detection device can also monitor the real-time measurement and stability of the half-wave voltage of the high-speed electro-optical phase modulator, further expanding the use scenarios of the automated test device.

[0005] In a first aspect, an embodiment of the present application provides an automated test device for high-frequency characteristics of a high-speed electro-optical phase modulator, comprising:

[0006] A laser module, the laser module is connected to the input end of the electro-optical phase modulator to be tested and is used to output a laser with stable power;

[0007] A radio frequency signal generating module, the radio frequency signal generating module is electrically connected to the electro-optical phase modulator to be tested, and is used to control the electro-optical phase modulator to be tested to modulate the laser light emitted by the laser module;

[0008] A beam splitter, the beam splitter is connected to the output end of the electro-optical phase modulator to be tested, and is used to split the laser output by the electro-optical phase modulator to be tested into two first branches and a second branch with the same power;

[0009] A delay device, the delay device is arranged on the first branch and is used to prolong the time for the laser to pass through the first branch;

[0010] An adjustable attenuation line, the adjustable attenuation line is arranged on the second branch and is used to control the power of the laser in the second branch;

[0011] A beam combiner, wherein the first branch and the second branch are connected to an input end of the beam combiner, and is used to combine the lasers of the first branch and the second branch into one combined laser;

[0012] A power meter, used to detect the power value of the synthetic laser;

[0013] A control processing module, the control processing module is electrically connected to the RF signal generating module and the power meter, and is used to control the modulation instruction issued by the RF signal generating module, and receive the power value detected by the power meter in real time, calculate the half-wave voltage through the power value, and form a frequency response curve of the electro-optical phase modulator to be tested according to the half-wave voltage.

[0014] In the technical solution of the embodiment of the present application, each component is controlled by the control processing module, thereby realizing the automatic detection of the high-frequency characteristics of the electro-optical phase modulator to be tested, which is not only simple and reliable in structure, but also easy to operate. Secondly, the above-mentioned automatic detection device can also perform real-time measurement and stability monitoring of the half-wave voltage of the high-speed electro-optical phase modulator, further expanding the use scenarios of the automatic test device.

[0015] In some embodiments, a disturbance device is further included, wherein the disturbance device is disposed on the second branch and is used to apply a physical disturbance to the second branch.

[0016] In this embodiment, a physical disturbance is applied to the second branch by a disturbance device to introduce random phase / polarization noise, thereby improving the test efficiency and environmental robustness of the automatic test device for high-frequency characteristics of a high-speed electro-optical phase modulator.

[0017] In some embodiments, the disturbance device includes a vibration table and a drive motor, the vibration table is arranged at the driving end of the drive motor, a slot is provided on the vibration table, the second branch is arranged in the slot, and the drive motor applies disturbance to the second branch through the vibration table.

[0018] In this embodiment, a vibration table is driven by a driving motor to generate low-amplitude mechanical vibrations of tens to kilohertz, and the vibrations are transmitted to the branch optical fiber, introducing random phase / polarization noise in the branch, thereby improving the test efficiency and environmental robustness of the high-speed electro-optic phase modulator high-frequency characteristics automated test device.

[0019] In some embodiments, the delay device includes a delay line and a stepper motor, the delay line is arranged on the first branch, and the stepper motor is connected to the delay line for controlling the delay of the delay line.

[0020] In this embodiment, since the stepper motor can drive a specific optical element in the delay line (such as a prism or a movable part in an optical fiber delay line) to translate on a horizontal guide rail, this slight displacement change will significantly change the transmission path length of the optical signal, thereby producing an adjustable delay effect. Therefore, the optical signal is first converted into a form suitable for optical fiber transmission and transmitted through an optical fiber or a waveguide. When the optical signal passes through the delay element controlled by the stepper motor, its transmission path will change, causing the optical signal to experience paths of different lengths during transmission, thereby achieving adjustment of the delay time. At the same time, since the stepper motor has the characteristics of high precision and high repeatability, the step-adjustable optical delay line can achieve precise control of the delay time of the optical signal.

[0021] In some embodiments, the stepper motor is a stepper motor with adjustable stroke.

[0022] In this embodiment, the stroke-adjustable stepping motor enables the automated testing device to test a wider frequency coverage range.

[0023] In some embodiments, a display device is also included, and the display device is electrically connected to the control processing module.

[0024] In this embodiment, the display device further enhances the user experience by displaying various parameter values ​​and test results in real time.

[0025] In a second aspect, an embodiment of the present application provides a method for automatically testing high-frequency characteristics of a high-speed electro-optical phase modulator, which is used in an automatic testing device for high-frequency characteristics of a high-speed electro-optical phase modulator as described in any one of the above items, comprising:

[0026] Controlling the laser module to emit laser light toward the electro-optical phase modulator to be tested;

[0027] Adjusting the adjustable attenuation line so that the minimum power value detected by the power meter approaches 0;

[0028] The control processing module sends an initial radio frequency signal to the electro-optical phase modulator to be tested through the radio frequency signal generating module, and the electro-optical phase modulator to be tested modulates the laser emitted by the laser module according to the initial radio frequency signal;

[0029] Adjusting the delay of the delay device, gradually adjusting the delay time of the delay device from 0 to a maximum value;

[0030] During the process of gradually adjusting the delay of the delay device from 0 to the maximum value, the power meter transmits the detected power value to the control processing module in real time, and the control processing module calculates the power-delay time curve envelope diagram according to the power value;

[0031] The delay time of the delay device is set to an initial time, wherein the initial time is a scale value of any delay time between two adjacent maximum powers in the power-delay time curve envelope diagram;

[0032] Set the target power value;

[0033] Controlling the radio frequency signal generating module to continuously send a radio frequency signal to the electro-optical phase modulator to be tested, wherein the peak-to-peak value of the radio frequency signal gradually increases from 0;

[0034] When the power value detected by the power meter reaches the target power value, obtaining the peak-to-peak value of the radio frequency signal corresponding to the target power value;

[0035] A half-wave voltage is calculated based on the peak-to-peak value of the radio frequency signal corresponding to the target power value, and a frequency response curve of the electro-optical phase modulator to be tested is formed based on the half-wave voltage.

[0036] In this embodiment, the automated detection device realizes automated detection of the high-frequency characteristics of the electro-optical phase modulator to be tested through the above-mentioned automated testing method, and its structure is not only simple and reliable, but also easy to operate. Secondly, the above-mentioned automated detection device can measure and monitor the stability of the half-wave voltage of the high-speed electro-optical phase modulator in real time, further expanding the use scenarios of the automated test device.

[0037] In some embodiments, calculating the half-wave voltage according to the peak-to-peak value of the RF signal corresponding to the target power value includes:

[0038] The target power value is the maximum power in the power-delay time curve envelope diagram. In the process of the RF signal peak-to-peak value gradually increasing from 0, record the RF signal peak-to-peak value when the maximum power value detected by the power meter changes to the target power value for the first time. At this time, the control processing module calculates the phase modulator to be tested at a wavelength of and the RF frequency is Half-wave voltage :

[0039]

[0040] in, is the half-wave voltage, is the wavelength of the laser output by the laser module, a radio frequency frequency at which the radio frequency signal generating module sends the radio frequency signal to the electro-optical phase modulator to be tested, a is a constant quantity, is an algebraic equation The smallest positive root of .

[0041] In this embodiment, the half-wave voltage is calculated by the above method. Not only is the algorithm formula simple, but the half-wave voltage of the phase modulator can also be accurately obtained directly through optical power feedback adjustment, thereby realizing automatic testing of high-frequency characteristics of high-speed electro-optical phase modulators.

[0042] In some embodiments, calculating the half-wave voltage according to the peak-to-peak value of the RF signal corresponding to the target power value includes:

[0043] The target power value is the maximum power in the power-delay time curve envelope diagram. In the process of the RF signal peak-to-peak value gradually increasing from 0, record the RF signal peak-to-peak value when the minimum power value detected by the power meter changes to the target power value for the first time. At this time, the control processing module calculates the phase modulator to be tested at a wavelength of and the RF frequency is Half-wave voltage :

[0044]

[0045] in, is the half-wave voltage, is the wavelength of the laser output by the laser module, a radio frequency frequency at which the radio frequency signal generating module sends the radio frequency signal to the electro-optical phase modulator to be tested, b is a constant quantity, is an algebraic equation The smallest positive root of .

[0046] In this embodiment, the half-wave voltage is calculated by the above method. Not only is the algorithm formula simple, but the half-wave voltage of the phase modulator can also be accurately obtained directly through optical power feedback adjustment, thereby realizing automatic testing of high-frequency characteristics of high-speed electro-optical phase modulators.

[0047] In some embodiments, the initial time is the average value of the delay times corresponding to two adjacent maximum powers in the envelope diagram of the power-delay time curve.

[0048] In this embodiment, by taking the average value of the delay times corresponding to two adjacent maximum powers in the power-delay time curve envelope diagram as the initial time, the sensitivity and accuracy of the automatic testing device when testing the half-wave voltage are further improved.

[0049] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0051] Figure 1 This is a schematic diagram of the structure of an automated test device for high-frequency characteristics of a high-speed electro-optical phase modulator in an embodiment of the present application;

[0052] Figure 2-Figure 4 The following are envelope diagrams of power-delay time curves of three typical styles given in the embodiments of the present application;

[0053] Figure 5 This is a schematic diagram of the structure of the disturbance device part in the embodiment of the present application;

[0054] Description of reference numerals:

[0055] 1. Laser module; 2. Electro-optical phase modulator to be tested; 3. RF signal generation module;

[0056] 4. beam splitter; 51. second branch; 52. adjustable attenuation line; 53. vibration table; 54. drive motor;

[0057] 6. Delay device; 7. Beam combiner; 8. Power meter; 9. Control processing module. DETAILED DESCRIPTION

[0058] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0059] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0060] The term "comprising" herein indicates the presence of the described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. The terms "comprising", "including", "having" and their variations all mean "including but not limited to", excluding that they are specially emphasized in other ways. Hereinafter, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating one or more of the features. In the description of the embodiments of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0061] In this article, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0062] Phase modulators are widely used in important fields such as fiber lasers and optical communication systems. Typical application scenarios include using phase modulators to broaden the spectrum to suppress nonlinear effects in fiber laser systems, compressing phase modulation chirps through dispersion devices to obtain pulse signals, using phase modulators in optical communications to form hexadecimal quadrature amplitude modulation (16-QAM) optical transmitters and optical code division multiple access (OCDMA) systems, and generating continuously adjustable millimeter wave signals. With the development of technology in this field, the performance requirements for phase modulators are becoming higher and higher. Half-wave voltage and its frequency response curve are one of the most important performance parameters of phase modulators, especially for high-speed phase modulators. The measurement of its half-wave voltage and frequency response curve is even more important.

[0063] At present, the measurement methods of the half-wave voltage of the phase modulator include spectrum analysis method, FM-IM conversion method, optical heterodyne method, etc. The spectrum analysis method obtains the half-wave voltage by measuring the intensity information of the spectral sideband after phase modulation; the FM-IM conversion method converts the phase modulation signal into an intensity modulation signal, and obtains the half-wave voltage by measuring the spectrum of the intensity modulation signal; the optical heterodyne method uses a spectrum analyzer and a photodetector to measure the difference frequency signal between the modulated light and the frequency-shifted light to obtain the half-wave voltage. The test accuracy of the spectrum analysis method is limited by the measurement accuracy of the spectrum measurement device / equipment, and the cost is often high. The FM-IM conversion method and the optical heterodyne method have complex systems and cumbersome operations, making it difficult to achieve reliable automated measurements.

[0064] In order to solve the technical problem of how to provide a new type of automatic test device and method for high-frequency characteristics of high-speed electro-optical phase modulators to realize the automatic measurement of half-wave voltage of high-speed electro-optical phase modulators, the present application provides an automatic test device and method for high-frequency characteristics of high-speed electro-optical phase modulators, which controls the radio frequency signal generating module 3 to send radio frequency signals of different frequencies and peak values ​​to the electro-optical phase modulator 2 to be tested through the control processing module 9, and detects the power value of the power meter 8 when sending radio frequency signals of different frequencies and peak values ​​to the electro-optical phase modulator 2 to be tested through the power meter 8, and then calculates the half-wave voltage through the power value, so as to achieve the automatic detection of the high-frequency characteristics of the electro-optical phase modulator 2 to be tested. The structure of the automatic detection device is not only simple and reliable, but also easy to operate. Secondly, the half-wave voltage of the high-speed electro-optical phase modulator can also be measured and monitored for stability through the automatic detection device, which further expands the technical effect of the use scenario of the automatic test device.

[0065] Figure 1A schematic diagram of the structure of an automated test device for high-frequency characteristics of a high-speed electro-optical phase modulator provided in an embodiment of the present application, which is used to test the high-frequency characteristics of an electro-optical phase modulator 2 to be tested, comprises: a laser module 1, a radio frequency signal generating module 3, a beam splitter 4, a delay device 6, an adjustable attenuation line 52, a beam combiner 7, a power meter 8 and a control processing module 9, wherein the laser module 1 is connected to the input end of the electro-optical phase modulator 2 to be tested, and is used to output a laser with stable power; the radio frequency signal generating module 3 is electrically connected to the electro-optical phase modulator 2 to be tested, and is used to control the electro-optical phase modulator 2 to be tested to modulate the laser emitted by the laser module 1; the beam splitter 4 It is connected to the output end of the electro-optical phase modulator 2 to be tested, and is used to divide the laser output by the electro-optical phase modulator 2 to be tested into two first branches and second branches 51 with the same power; the delay device 6 is arranged on the first branch, and is used to prolong the time for the laser to pass through the first branch; the adjustable attenuation line 52 is arranged on the second branch 51, and is used to control the power of the laser in the second branch 51; the first branch and the second branch 51 are connected to the input end of the combiner 7, and is used to combine the lasers of the first branch and the second branch 51 into one combined laser; the power meter 8 is used to detect the power value of the combined laser; the control processing module 9 is electrically connected to the RF signal generating module 3 and the power meter 8.

[0066] In this embodiment, the automatic testing device detects the high-frequency characteristics of the electro-optical phase modulator 2 to be tested and is mainly divided into two steps: an initialization step and an automatic testing step.

[0067] In the initialization step, the electro-optic phase modulator 2 to be tested is connected to the automated testing device, and the laser module 1 is controlled to output a stable laser.

[0068] First, the adjustable attenuation line 52 is adjusted, and after the minimum power value detected by the power meter 8 approaches 0, the delay of the delay device 6 is adjusted, thereby completing the initialization of the test device.

[0069] In this embodiment, by adjusting the adjustable attenuation line 52 so that the minimum power detected by the power meter 8 approaches 0, the difference between the power of the second branch 51 and the power of the first branch can be effectively eliminated, thereby improving the stability and accuracy of the system.

[0070] In the process of adjusting the delay of the delay device 6, the control processing module 9 sends an initial RF signal to the electro-optical phase modulator 2 to be tested through the RF signal generating module 3, and the electro-optical phase modulator 2 to be tested modulates the laser emitted by the laser module 1 according to the initial RF signal; the delay of the delay device 6 is adjusted, and the delay time of the delay device 6 is gradually adjusted from 0 to the maximum value; in the process of gradually adjusting the delay of the delay device 6 from 0 to the maximum value, the power meter 8 transmits the detected power value to the control processing module 9 in real time, and the control processing module 9 calculates the power-delay time curve envelope diagram according to the power value; the delay time of the delay device 6 is set to the initial time, and the initial time is the scale value of any delay time between two adjacent maximum powers in the power-delay time curve envelope diagram.

[0071] It should be noted that in actual use, it is found that the average value of the two adjacent maximum powers corresponding to the delay time in the power-delay time curve envelope diagram is taken at the initial moment, and the sensitivity and accuracy of the automatic test device when testing the half-wave voltage are greatly improved. Therefore, in this embodiment, the average value of the two adjacent maximum powers corresponding to the delay time in the power-delay time curve envelope diagram is preferably used at the initial moment. It should also be pointed out that due to the difference in the effective length of the two branches of the automatic test device for the high-frequency characteristics of the electro-optic phase modulator and the peak-to-peak value of the applied RF signal, the above-mentioned power-delay time curve envelope diagram may present various forms during the initialization operation. Figure 2-4 Three typical styles are given.

[0072] In the automated test step, the control processing module 9 controls the RF signal generating module 3 to continuously send the RF signal peak-to-peak value to the electro-optical phase modulator 2 to be tested, and gradually increases the RF signal from 0. During the process of continuously sending the RF signal to the electro-optical phase modulator 2 to be tested, the power meter 8 detects the power value of the synthetic laser in real time. When the power value detected by the power meter 8 reaches the target power value, the peak-to-peak value of the RF signal corresponding to the target power value is obtained; the control processing module 9 calculates the half-wave voltage based on the peak-to-peak value of the RF signal corresponding to the target power value.

[0073] After the control processing module 9 obtains the half-wave voltage, the control processing module 9 obtains the half-wave voltage frequency by frequency according to the RF frequency of the RF signal continuously sent to the electro-optic phase modulator 2 to be tested, thereby forming a frequency response curve of the electro-optic phase modulator 2 to be tested.

[0074] In this embodiment, the high-frequency characteristics of the electro-optical phase modulator 2 to be tested can be automatically tested by the automated testing device, and its structure is not only simple and reliable, but also easy to operate. Secondly, the real-time measurement and stability monitoring of the half-wave voltage of the high-speed electro-optical phase modulator by the above-mentioned automated testing device further expands the use scenarios of the automated testing device.

[0075] Further, in the embodiments of the present application, Figure 5 As shown, the automated detection device also includes a disturbance device, which is disposed on the second branch 51. During the use of the automated detection device, a physical disturbance is applied to the second branch 51 by the disturbance device, thereby introducing random phase / polarization noise into the branch, thereby improving the test efficiency and environmental robustness of the automated test device for high-frequency characteristics of a high-speed electro-optical phase modulator.

[0076] Specifically, the disturbance device includes a vibration table 53 and a drive motor 54. The vibration table 53 is arranged at the driving end of the drive motor 54. A card slot is provided on the vibration table 53. The second branch 51 is arranged in the card slot. The drive motor 54 applies disturbance to the second branch 51 through the vibration table 53. During use, the second branch 51 is placed in the card slot, and the vibration table 53 is driven by the drive motor 54 to generate low-amplitude mechanical vibrations of tens to kilohertz, and the vibration is transmitted to the branch optical fiber, introducing random phase / polarization noise in the second branch, thereby improving the test efficiency and environmental robustness of the automatic test device for high-frequency characteristics of the high-speed electro-optical phase modulator.

[0077] In this embodiment, the delay device 6 includes a delay line and a stepper motor. The delay line is arranged on the first branch, and the stepper motor is connected to the delay line to control the delay of the delay line.

[0078] In an embodiment, a stepper motor can drive a specific optical element in a delay line (such as a prism or a movable part in a fiber delay line) to translate on a horizontal guide rail. This tiny displacement change will significantly change the transmission path length of the optical signal, thereby producing an adjustable delay effect.

[0079] In the delay device 6, the optical signal is first converted into a form suitable for optical fiber transmission and transmitted through the optical fiber or waveguide. When the optical signal passes through the delay element controlled by the stepper motor, its transmission path will change, causing the optical signal to experience paths of different lengths during transmission, thereby achieving adjustment of the delay time. At the same time, since the stepper motor has the characteristics of high precision and high repeatability, the step-adjustable optical delay line can achieve precise control of the delay time of the optical signal.

[0080] In this embodiment, the stepper motor is a stepper motor with adjustable stroke. Assuming that the delay device 6 is a delay line of a space reflector structure, the number of steps of the stepper motor is 500. When the stepper motor stroke is 50 mm and 5 mm, the frequency response characteristics of 3-30 GHz and 30-300 GHz can be tested respectively. The adjustable stepper motor enables the automated testing device to test a wider frequency coverage range.

[0081] In this embodiment, the automatic testing device further includes a display device, which is electrically connected to the control processing module 9. The display device further enhances the user experience by displaying various parameter values ​​and test results in real time.

[0082] On the second aspect, the present application also provides a method for automated testing of the high-frequency characteristics of a high-speed electro-optical phase modulator, which is used for any of the above-mentioned automated testing devices for high-frequency characteristics of a high-speed electro-optical phase modulator. When using the automated testing device for high-frequency characteristics of a high-speed electro-optical phase modulator to automatically detect the high-frequency characteristics of the electro-optical phase modulator 2 to be tested, it is mainly divided into two steps: an initialization step and an automated testing step.

[0083] During the initialization step, the laser module 1 is controlled to emit laser light to the electro-optical phase modulator 2 to be tested;

[0084] Adjust the adjustable attenuation line 52 so that the minimum power value detected by the power meter 8 approaches 0;

[0085] The control processing module 9 sends an initial radio frequency signal to the electro-optical phase modulator 2 to be tested through the radio frequency signal generating module 3, and the electro-optical phase modulator 2 to be tested modulates the laser emitted by the laser module 1 according to the initial radio frequency signal;

[0086] Adjust the delay of the delay device 6, and gradually adjust the delay time of the delay device 6 from 0 to the maximum value;

[0087] When the delay of the delay device 6 is gradually adjusted from 0 to the maximum value, the power meter 8 transmits the detected power value to the control processing module 9 in real time, and the control processing module 9 calculates the power-delay time curve envelope diagram according to the power value;

[0088] The delay time of the delay device 6 is set to the initial time, and the initial time is the scale value of any delay time between two adjacent maximum powers in the power-delay time curve envelope diagram;

[0089] In the automated test step, the target power value is set according to the power-delay time curve envelope diagram; the RF signal generating module 3 is controlled to continuously send the RF signal to the electro-optical phase modulator 2 to be tested, and the RF signal peak-to-peak value of the RF signal gradually increases from 0; when the power value detected by the power meter 8 reaches the target power value, the RF signal peak-to-peak value corresponding to the target power value is obtained;

[0090] After the control processing module 9 obtains the half-wave voltage, the control processing module 9 obtains the half-wave voltage frequency by frequency according to the RF frequency of the RF signal continuously sent to the electro-optic phase modulator 2 to be tested, thereby forming a frequency response curve of the electro-optic phase modulator 2 to be tested.

[0091] In this embodiment, the high-frequency characteristics of the electro-optical phase modulator 2 to be tested can be automatically tested by the automated testing device, and its structure is not only simple and reliable, but also easy to operate. Secondly, the real-time measurement and stability monitoring of the half-wave voltage of the high-speed electro-optical phase modulator by the above-mentioned automated testing device further expands the use scenarios of the automated testing device.

[0092] It should be noted that in actual use, it is found that the average value of the two adjacent maximum power corresponding delay moments in the power-delay moment curve envelope diagram is taken as the initial moment, and the sensitivity and accuracy of the automatic testing device when testing the half-wave voltage are greatly improved. Therefore, in this embodiment, the average value of the two adjacent maximum power corresponding delay moments in the power-delay moment curve envelope diagram is preferentially selected at the initial moment.

[0093] In this embodiment, there are two parallel calculation schemes for calculating the half-wave voltage based on the peak-to-peak value of the RF signal corresponding to the target power value. The automated testing device can select any one of the calculation schemes according to needs during actual use.

[0094] The first calculation scheme:

[0095] In this calculation scheme, the maximum power in the target power value power-delay time curve envelope diagram is , when the peak-to-peak value of the RF signal gradually increases from 0, record the peak-to-peak value of the RF signal when the maximum power value detected by the power meter changes to the target power value for the first time. The control processing module calculates the phase modulator to be tested at this wavelength according to the following formula and RF frequency Half-wave voltage :

[0096]

[0097] in, is the half-wave voltage, is the wavelength of the laser output by the laser module, The RF frequency at which the RF signal generating module sends the RF signal to the electro-optical phase modulator to be tested, a is a constant quantity, is an algebraic equation The smallest positive root of .

[0098] In this calculation scheme, the coefficient The following typical values ​​are possible:

[0099]

[0100] The second calculation scheme:

[0101] Target power value The maximum power in the power-delay time curve envelope diagram , when the peak-to-peak value of the RF signal gradually increases from 0, record the peak-to-peak value of the RF signal when the minimum power value detected by the power meter changes to the target power value for the first time The control processing module calculates the phase modulator to be tested at this wavelength according to the following formula and RF frequency Half-wave voltage :

[0102]

[0103] in, is the half-wave voltage, is the wavelength of the laser output by the laser module, The RF frequency at which the RF signal generating module sends the RF signal to the electro-optical phase modulator to be tested, b is a constant quantity, is an algebraic equation The smallest positive root of .

[0104] coefficient The following typical values ​​are possible:

[0105]

[0106] In the embodiment, the above two calculation schemes not only have simple algorithm formulas, but also can accurately obtain the half-wave voltage of the phase modulator directly through optical power feedback regulation.

[0107] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A high-speed electro-optical phase modulator high-frequency characteristics automatic test device, used to test the high-frequency characteristics of the electro-optical phase modulator to be tested, characterized in that: include: A laser module, the laser module is connected to the input end of the electro-optical phase modulator to be tested and is used to output a laser with stable power; A radio frequency signal generating module, the radio frequency signal generating module is electrically connected to the electro-optical phase modulator to be tested, and is used to control the electro-optical phase modulator to be tested to modulate the laser light emitted by the laser module; A beam splitter, the beam splitter is connected to the output end of the electro-optical phase modulator to be tested, and is used to split the laser output by the electro-optical phase modulator to be tested into two first branches and a second branch with the same power; A delay device, the delay device is arranged on the first branch and is used to prolong the time for the laser to pass through the first branch; An adjustable attenuation line, the adjustable attenuation line is arranged on the second branch and is used to control the power of the laser in the second branch; A beam combiner, wherein the first branch and the second branch are connected to an input end of the beam combiner, and is used to combine the lasers of the first branch and the second branch into one combined laser; A power meter, used to detect the power value of the synthetic laser; A control processing module, the control processing module is electrically connected to the RF signal generating module and the power meter, and is used to control the RF signal generating module and receive the power value detected by the power meter in real time, calculate the half-wave voltage of the electro-optical phase modulator to be tested according to the power value, and form a frequency response curve of the electro-optical phase modulator to be tested according to the half-wave voltage; Wherein, the delay device includes a delay line and a stepper motor, the delay line is arranged on the first branch, and the stepper motor is connected to the delay line for controlling the delay of the delay line.

2. The automatic test device for high-frequency characteristics of a high-speed electro-optical phase modulator according to claim 1, characterized in that: It also includes a disturbance device, which is arranged on the second branch and is used to apply a physical disturbance to the second branch.

3. The automatic test device for high-frequency characteristics of a high-speed electro-optical phase modulator according to claim 2, characterized in that: The disturbance device includes a vibration table and a drive motor. The vibration table is arranged at the drive end of the drive motor. A slot is provided on the vibration table. The second branch is arranged in the slot. The drive motor applies disturbance to the second branch through the vibration table.

4. The automatic test device for high-frequency characteristics of a high-speed electro-optical phase modulator according to claim 1, characterized in that: The stepper motor is a stepper motor with adjustable stroke.

5. The automatic test device for high-frequency characteristics of a high-speed electro-optical phase modulator according to claim 1, characterized in that: It also includes a display device, which is electrically connected to the control processing module.

6. A method for automatically testing the high-frequency characteristics of a high-speed electro-optical phase modulator, used in the device for automatically testing the high-frequency characteristics of a high-speed electro-optical phase modulator as claimed in any one of claims 1 to 5, characterized in that: include: Controlling the laser module to emit laser light toward the electro-optical phase modulator to be tested; Adjusting the adjustable attenuation line so that the minimum power value detected by the power meter approaches 0; The control processing module sends an initial radio frequency signal to the electro-optical phase modulator to be tested through the radio frequency signal generating module, and the electro-optical phase modulator to be tested modulates the laser emitted by the laser module according to the initial radio frequency signal; Adjusting the delay of the delay device, gradually adjusting the delay time of the delay device from 0 to a maximum value; During the process of gradually adjusting the delay time of the delay device from 0 to the maximum value, the power meter transmits the detected power value to the control processing module in real time, and the control processing module calculates the power-delay time curve envelope diagram according to the power value; The delay time of the delay device is set to an initial time, wherein the initial time is a scale value of any delay time between two adjacent maximum powers in the power-delay time curve envelope diagram; Set the target power value; Controlling the radio frequency signal generating module to continuously send a radio frequency signal to the electro-optical phase modulator to be tested, wherein the peak-to-peak value of the radio frequency signal gradually increases from 0; When the power value detected by the power meter reaches the target power value, obtaining the peak-to-peak value of the radio frequency signal corresponding to the target power value; A half-wave voltage is calculated based on the peak-to-peak value of the radio frequency signal corresponding to the target power value, and a frequency response curve of the electro-optical phase modulator to be tested is formed based on the half-wave voltage.

7. The method for automatically testing high-frequency characteristics of a high-speed electro-optical phase modulator according to claim 6, characterized in that: Calculating the half-wave voltage according to the peak-to-peak value of the RF signal corresponding to the target power value includes: The target power value is the maximum power in the power-delay time curve envelope diagram. In the process of the RF signal peak-to-peak value gradually increasing from 0, record the RF signal peak-to-peak value when the maximum power value detected by the power meter changes to the target power value for the first time. At this time, the control processing module calculates the phase modulator to be tested at a wavelength of and the RF frequency is Half-wave voltage : in, is the half-wave voltage, is the wavelength of the laser output by the laser module, a radio frequency frequency at which the radio frequency signal generating module sends the radio frequency signal to the electro-optical phase modulator to be tested, a is a constant quantity, is an algebraic equation The smallest positive root of .

8. The method for automatically testing high-frequency characteristics of a high-speed electro-optical phase modulator according to claim 6, characterized in that: Calculating the half-wave voltage according to the peak-to-peak value of the RF signal corresponding to the target power value includes: The target power value is the maximum power in the power-delay time curve envelope diagram. In the process of the RF signal peak-to-peak value gradually increasing from 0, record the RF signal peak-to-peak value when the minimum power value detected by the power meter changes to the target power value for the first time. At this time, the control processing module calculates the phase modulator to be tested at a wavelength of and the RF frequency is Half-wave voltage : in, is the half-wave voltage, is the wavelength of the laser output by the laser module, a radio frequency frequency at which the radio frequency signal generating module sends the radio frequency signal to the electro-optical phase modulator to be tested, b is a constant quantity, is an algebraic equation The smallest positive root of .

9. The method for automatically testing high-frequency characteristics of a high-speed electro-optical phase modulator according to claim 6, characterized in that: The initial time is the average value of the delay times corresponding to two adjacent maximum powers in the power-delay time curve envelope diagram.

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