Optical sampling oscilloscope sampling front end based on optical sampling electric quantization

Abstract

The application discloses a light oscilloscope sampling front end based on optical sampling electric quantization, comprising a to-be-measured electric signal input module, an optical sampling pulse generation and shaping module, an electric-optical sampling module, an optical domain mapping module, an optical-electric conversion and preamplification module and an electric quantization and digital reconstruction module which are sequentially matched; the to-be-measured electric signal input module is used for introducing a to-be-measured signal into the sampling front end with a specified impedance and amplitude range; and the optical sampling pulse generation and shaping module is used for outputting an optical sampling pulse sequence with a repetition frequency, a pulse width less than a corresponding preset value and a timing jitter less than a corresponding preset value. The light oscilloscope sampling front end based on optical sampling electric quantization disclosed by the application solves the technical problems of the existing electronic oscilloscope sampling front end, such as limited input bandwidth, sensitivity to jitter, high power consumption and high cost of an ultra-high-speed ADC.

Description

Technical Field

[0001] This invention belongs to the field of high-speed electronic and photonic measurement technology, specifically relating to a sampling front end for an optical oscilloscope based on optical sampling electroquantization. Background Technology

[0002] With the rapid development of high-speed communication, millimeter-wave / terahertz devices, and high-speed serial interfaces, the bandwidth and edge speed of the electrical signals under test are constantly increasing, and the performance requirements for signal measurement equipment are also constantly rising. The sampling front end of traditional electronic oscilloscopes usually relies on ultra-high-speed sample-and-hold circuits and wideband amplifiers. Its equivalent input bandwidth is limited by factors such as transistor speed, package interconnection, and front-end jitter, making it difficult to meet the measurement requirements of ultra-wideband signals.

[0003] When the sampling clock jitter reaches the same order of magnitude as the signal rising edge, the timing jitter directly translates into amplitude error, causing a significant decrease in the effective number of bits of the oscilloscope and affecting measurement accuracy. Furthermore, the power consumption and cost of ultra-high-speed ADCs (analog-to-digital converters) increase dramatically with the sampling rate, making it difficult to simultaneously meet the technical requirements of high bandwidth, large acquisition window, and high resolution in ultra-wideband measurement scenarios.

[0004] Therefore, there is an urgent need in this field for a novel sampling front-end architecture that can reduce the reliance on ultra-high-speed electronic sampling circuits while maintaining high time resolution and wide input bandwidth, thus solving the aforementioned problems in the prior art. Summary of the Invention

[0005] The main objective of this invention is to provide an optical oscilloscope sampling front-end based on optical sampling electro-quantization, solving the technical problems of limited input bandwidth, sensitivity to jitter, high power consumption and cost of ultra-high-speed ADCs in existing electronic oscilloscope sampling front-ends; at the same time, it provides an optical oscilloscope including this sampling front-end to achieve high-precision, low-power measurement of ultra-wideband electrical signals greater than 100GHz.

[0006] To achieve the above objectives, the present invention provides a sampling front end for an optical oscilloscope based on optical sampling and electro-amplification, comprising, in sequence, a test electrical signal input module, an optical sampling pulse generation and shaping module, an electro-optic sampling module, an optical domain mapping module, a photoelectric conversion and preamplification module, and an electro-amplification and digital reconstruction module; The electrical signal input module under test is used to introduce the signal under test into the sampling front end with a specified impedance and amplitude range; The optical sampling pulse generation and shaping module is used to output an optical sampling pulse sequence with a repetition frequency, pulse width less than the corresponding preset value, and timing jitter less than the corresponding preset value. The electro-optic sampling module includes an electro-optic modulator and a bias control unit. It is used to enable the optical sampling pulse sequence and the electrical signal under test to interact in the electro-optic modulator, so that the electrical signal under test modulates the intensity of the optical sampling pulse sequence, thereby generating modulated light carrying the instantaneous information of the signal under test. The bias control unit maintains the electro-optic modulator at the orthogonal point to obtain an approximately linear electro-optic mapping and suppress drift. The optical domain mapping module is used to perform at least one processing on the modulated light, including dispersion broadening, optical delay scanning or wavelength division / time division multiplexing, thereby mapping the ultra-wideband signal under test into an equivalent low-speed waveform that is compatible with the electric transformer. The photoelectric conversion and preamplifier module is used to convert the mapped modulated light into an electrical signal and perform noise-optimized amplification. The electrical conversion and digital reconstruction module is used to perform analog-to-digital conversion on electrical signals and reconstruct the waveform of the signal under test according to the mapping relationship.

[0007] As a further preferred technical solution to the above technical solution, the optical sampling pulse generation and shaping module includes a mode-locked laser, a spectral stretcher, a dispersion compensator and a pulse compressor, and uses optical phase-locking or optical frequency combing to stabilize the frequency to reduce timing jitter.

[0008] As a further preferred technical solution of the above technical solution, the electro-optic modulator is a traveling wave Mach-Zehnder modulator or a traveling wave phase modulator. The electrode structure of the electro-optic modulator satisfies that the bandwidth is not less than 3 times the target measurement bandwidth, and the bias control unit is equipped with an automatic bias control function to achieve stable operating point of the electro-optic modulator.

[0009] As a further preferred technical solution of the above technical solution, the optical domain mapping module uses a dispersive medium to realize time stretching mapping, and the stretching factor M of time stretching satisfies M=(D1+D2) / D1, where D1 and D2 are the group delay dispersion parameters of the pre-dispersion and post-dispersion, respectively.

[0010] As a further preferred embodiment of the above technical solution, the optical domain mapping module uses wavelength division multiplexing and multi-channel delay lines to achieve parallel sampling, with each channel having a different relative delay. This allows for the expansion of a single capture window.

[0011] As a further preferred embodiment of the above technical solution, the input module for the electrical signal under test includes a switchable input interface, a programmable attenuator, a DC isolation / DC coupling selection unit, and an overvoltage protection and limiting circuit, wherein: Switchable input interfaces are used to achieve input impedance matching; The programmable attenuator enables precise adjustment of the amplitude of the signal under test. By controlling the attenuation ratio through the program, the electrical signals under test with different amplitudes are normalized to the amplitude range adapted by the electro-optic sampling module, ensuring the linearity of electro-optic modulation and the signal-to-noise ratio of the measurement. The DC isolation / DC coupling selection unit enables flexible switching of signal coupling modes to adapt to the measurement requirements of different types of electrical signals under test. When DC coupling is selected, both the DC and AC components of the signal under test are transmitted, which is suitable for scenarios where electrical signals containing DC bias need to be measured. When DC isolation is selected, the DC component in the signal is blocked, and only the AC component is transmitted, which is suitable for scenarios where only AC signals need to be measured, or where it is necessary to eliminate the influence of the DC bias of the signal under test on the operating point of the subsequent electro-optic modulator. Overvoltage protection and limiting circuits are used to limit the maximum amplitude of input signals and suppress surge signals.

[0012] As a further preferred embodiment of the above technical solution, the photoelectric conversion and preamplification module includes a balanced detector and a transimpedance amplifier. The balanced detector is used to suppress relative intensity noise, and the transimpedance amplifier is used to achieve bandwidth-noise matching.

[0013] As a further preferred embodiment of the above technical solution, the electro-quantization and digital reconstruction module includes a multi-channel interleaved ADC, a time-base calibration unit, and a digital equalization unit, wherein: The multi-channel interleaved ADC realizes analog-to-digital conversion from analog electrical signals to digital signals, and adopts a multi-channel interleaved architecture to improve the overall equivalent sampling rate through multi-channel timing interleaving, which matches the sampling requirements of ultra-wideband test signals after optical domain mapping. The timing calibration unit is used to estimate and compensate for the sampling deviation between channels based on the reference pulse or the built-in calibration tone. For deviation estimation, relying on the built-in reference pulse, it accurately detects the inherent deviations of each channel in the multi-channel interleaved ADC in terms of sampling timing, phase, and delay, as well as the timing jitter and channel mismatch errors introduced during optical domain mapping and photoelectric conversion. For deviation compensation, based on the estimated deviation data, it performs timing alignment, phase correction, and delay compensation on the sampling data of each channel in the digital domain to eliminate the problem of sampling asynchrony between channels.

[0014] As a further preferred technical solution to the above technical solution, it also includes a reference clock and trigger synchronization module, which is used to align the optical sampling pulse sequence with the external trigger signal and output time stamp information for reconstructing the waveform of the signal under test.

[0015] The present invention also provides an optical oscilloscope, comprising the aforementioned optical oscilloscope sampling front end based on optical sampling electro-quantization. Attached Figure Description

[0016] Figure 1This is a flowchart illustrating the present invention.

[0017] Figure 2 This is a schematic diagram of the time stretching mapping principle in Embodiment 1 of the present invention.

[0018] Figure 3 This is a schematic diagram of wavelength division parallel sampling and delay scanning in Embodiment 2 of the present invention.

[0019] Figure 4 This is a flowchart of the digital reconstruction and calibration process of the present invention. Detailed Implementation

[0020] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0021] In a preferred embodiment of the present invention, those skilled in the art should note that the signals to be measured and the like involved in the present invention can be considered as prior art.

[0022] Example 1 (Time-stretched optical sampling electro-quantization front end).

[0023] like Figure 1-2 As shown, the present invention discloses a sampling front end for an optical oscilloscope based on optical sampling and electro-amplification, comprising, in sequence, a test electrical signal input module, an optical sampling pulse generation and shaping module, an electro-optic sampling module, an optical domain mapping module, a photoelectric conversion and preamplification module, and an electro-amplification and digital reconstruction module; The test signal input module is used to input the test signal. With specified impedance The sampling front end incorporates amplitude range; the input module for the electrical signal under test includes a switchable (50Ω / 100Ω) input interface, a programmable attenuator, a DC isolation / DC coupling selection unit, and overvoltage protection and limiting circuitry, wherein: The switchable input interface is used to achieve input impedance matching (in high-speed electrical signal measurement, impedance mismatch will cause signal reflection, attenuation and distortion. This interface can be flexibly switched according to the transmission characteristics of the electrical signal under test (such as the 50Ω transmission impedance commonly used in high-speed communication and millimeter wave devices, and the 100Ω impedance of some differential signals) to eliminate signal reflection and ensure that the electrical signal under test is transmitted to the sampling front end without distortion and with low loss, laying the foundation for subsequent accurate sampling). The programmable attenuator enables precise adjustment of the amplitude of the signal under test. By controlling the attenuation ratio through program control, it normalizes electrical signals of different amplitudes to the amplitude range adapted by the electro-optic sampling module, ensuring the linearity of electro-optic modulation and the signal-to-noise ratio of the measurement (the amplitude of the electrical signal under test varies greatly in different scenarios. If the signal amplitude is too large, it will exceed the linear operating range of the subsequent electro-optic modulator, resulting in modulation distortion; if the amplitude is too small, it will be overwhelmed by noise, affecting the measurement accuracy). The DC isolation / DC coupling selection unit enables flexible switching of signal coupling modes to adapt to the measurement requirements of different types of electrical signals under test. When DC coupling is selected, both the DC and AC components of the signal under test are transmitted, which is suitable for scenarios where electrical signals containing DC bias need to be measured. When DC isolation is selected, the DC component in the signal is blocked, and only the AC component is transmitted. This is suitable for scenarios where only AC signals need to be measured, or where it is necessary to eliminate the influence of the DC bias of the signal under test on the operating point of the subsequent electro-optic modulator (avoiding DC bias causing modulator operating point drift and ensuring modulation stability). The overvoltage protection and limiting circuit is used to limit the maximum amplitude of the input signal and suppress surge signals. (In actual testing, there may be sudden overvoltage or surge in the electrical signal under test, or high voltage signals may be introduced due to operational errors. This circuit can limit the maximum amplitude of the input signal to prevent excessive signals from entering precision optoelectronic devices such as the electro-optic modulator and optical sampling pulse module, thus avoiding device breakdown or damage due to overvoltage. On the other hand, it can suppress surge signals, reduce the interference of abnormal signals on the normal operation of the sampling front end, and ensure the hardware safety and long-term stable operation of the entire sampling front end.)

[0024] The optical sampling pulse generation and shaping module is used to output a repetition frequency of... Pulse width Less than the corresponding preset value ( (Preferred to be 2ps) and timing jitter Less than the corresponding preset value ( Optical sampling pulse sequence { (preferably 100 fs) The optical sampling pulse generation and shaping module includes a mode-locked laser, a spectral stretcher, a dispersion compensator, and a pulse compressor, and uses optical phase-locking or optical frequency combing for frequency stabilization to reduce timing jitter. This meets the requirements for high-precision time resolution.

[0025] The electro-optic sampling module includes an electro-optic modulator and a bias control unit. It is used to enable the interaction between the optical sampling pulse sequence and the electrical signal under test within the electro-optic modulator, causing the electrical signal under test to modulate the intensity of the optical sampling pulse sequence, thereby generating modulated light carrying instantaneous information of the signal under test. The bias control unit maintains the electro-optic modulator at the orthogonal point to obtain approximately linear electro-optic mapping and suppress drift. The modulated light... satisfy: ; in The coefficients are linear. To modulate the voltage, the bias control unit maintains the modulator at the quadrature point to obtain an approximately linear mapping and suppress drift; The electro-optic modulator is a traveling-wave Mach-Zehnder modulator (MZM) or a traveling-wave phase modulator. The electrode structure of the electro-optic modulator satisfies that the bandwidth is not less than 3 times the target measurement bandwidth, and the bias control unit is equipped with an automatic bias control function to stabilize the operating point of the electro-optic modulator. .

[0026] The optical domain mapping module is used to perform at least one processing on the modulated light, thereby mapping the ultra-wideband signal under test into an equivalent low-speed waveform that is adapted to the inductor. ; Where D1 and D2 are the group delay dispersion parameters of the pre-dispersion and post-dispersion, respectively; The optical domain mapping module uses a dispersive medium to achieve time-stretching mapping, and the stretching factor M of the time stretching satisfies M=(D1+D2) / D1.

[0027] The photoelectric conversion and preamplification module is used to convert the mapped modulated light Converted into electrical signals The signal is then amplified and optimized for noise reduction. The photoelectric conversion and pre-amplification module includes a balanced detector and a transimpedance amplifier. The balanced detector suppresses relative intensity noise, and the transimpedance amplifier achieves bandwidth-noise matching. The broadened optical signal enters the balanced detector for photoelectric conversion and suppression of relative intensity noise. After passing through the transimpedance amplifier and anti-aliasing filter, it is input to the ADC. The sampling rate of the ADC can be selected as 1 / M of the original target equivalent sampling rate.

[0028] The electrification and digital reconstruction module is used to convert electrical signals. Analog-to-digital conversion is performed, and the waveform of the signal under test is reconstructed according to the mapping relationship. The electrification and digital reconstruction module includes a multi-channel interleaved ADC, a time base calibration unit, and a digital equalization unit, wherein, as shown... Figure 4 As shown: Multi-channel interleaved ADCs achieve analog-to-digital conversion from analog electrical signals to digital signals. Employing a multi-channel interleaved architecture, the overall equivalent sampling rate is improved through multi-channel timing interleaving, matching the sampling requirements of ultra-wideband signals after optical domain mapping. Multi-channel interleaved ADCs achieve high equivalent sampling rates. ; The timing calibration unit is used to estimate and compensate for sampling deviations between channels based on reference pulses or built-in calibration tones. For deviation estimation, relying on built-in reference pulses (such as standard optical pulses from optical sampling modules) or calibration tones (standard electrical signals at fixed frequencies), it accurately detects the inherent deviations in sampling timing, phase, and delay of each channel in the multi-channel interleaved ADC, as well as the timing jitter and channel mismatch errors introduced during optical domain mapping and photoelectric conversion. For deviation compensation, based on the estimated deviation data, it performs timing alignment, phase correction, and delay compensation on the sampling data of each channel in the digital domain to eliminate the problem of sampling asynchrony between channels (avoiding reconstructed signal distortion caused by timing deviations and ensuring the high time resolution characteristics of the optical sampling architecture of this invention). The digital equalization unit is responsible for compensating for transmission losses across the entire system link and improving the fidelity of the reconstructed signal. Its core role is reflected in: 1. Compensate for nonlinear distortion and amplitude-frequency loss throughout the entire sampling front-end link, including signal distortion introduced by modulation nonlinearity of electro-optic modulator, dispersion loss of optical domain mapping, response imbalance of photoelectric conversion, frequency attenuation of transmission link, etc. 2. Perform amplitude-frequency characteristic correction, phase equalization, and nonlinear compensation on the digital signal quantized by the multi-channel interleaved ADC to correct the distortion of the signal in amplitude and phase and restore the original amplitude-frequency characteristics of the signal under test. 3. With the timing compensation of the time base calibration unit, the waveform quality of the reconstructed signal is further optimized to ensure high fidelity of the final output waveform of the signal under test, meeting the high-precision measurement requirements of ultra-wideband signals above 100GHz.

[0029] Example 2 (Wavelength Division Parallel Sampling and Delayed Scan Front End): like Figure 3 As shown, in this embodiment, based on embodiment 1, the optical domain mapping module uses wavelength division multiplexing and multi-channel delay lines to achieve parallel sampling, with each channel having a different relative delay. This allows for the expansion of the single capture window, extending it to: ; The optical domain mapping module is replaced with a wavelength division multiplexer (WDM) and a multi-channel delay line, using a wavelength division parallel sampling and delayed scanning optical domain mapping method. The specific improvements are as follows: 1. The broadband optical sampling pulse output from the optical sampling pulse generation and shaping module is input to the wavelength division multiplexer of the optical domain mapping module, where it is decomposed into N wavelength channels. Each wavelength channel is then processed by a different relative delay. After the delay line, the output is combined again; 2. Modulation and detection can be performed in two ways: ① Each wavelength channel is independently configured with an electro-optic modulator and a balanced detector to achieve independent detection and parallel quantization; ② After multiplexing, time-division multiplexing is used for single-channel detection and quantization. By setting different relative delays for each channel This forms an equivalent sampling phase scan, effectively expanding the single capture window and improving the equivalent sampling rate; In the digital reconstruction stage, channel gain / phase calibration and interpolation reconstruction algorithms are introduced into the digital domain of the electrification and digital reconstruction modules to suppress mismatch errors between multiple channels and ensure the fidelity of the reconstructed waveform.

[0030] Example 3 (Sampling front end with trigger synchronization and time tag): This embodiment, based on Embodiment 1 or Embodiment 2, adds a reference clock and trigger synchronization module to align the optical sampling pulse sequence with the external trigger signal and output time stamp information for reconstructing the waveform of the signal under test. The specific implementation is as follows: 1. The reference clock and trigger synchronization module receives an external trigger signal, and combines the external trigger signal with the optical sampling pulse generation and shaping module outputting an optical sampling pulse sequence, which is then converted into a reference mark through photoelectric / electro-optical conversion; 2. The module synchronizes and aligns the optical sampling pulse sequence with the external trigger signal to ensure that the sampling process is in sync with external events. 3. The processor records the time stamp information of each signal capture in real time and performs backtracking correction on the sampling phase based on the time stamp, thereby supporting the stable display of the signal under test in the equivalent sampling mode and realizing accurate analysis of signal jitter.

[0031] For this invention: Optional implementations and parameter suggestions: (1) Selection of electro-optic devices: When the target frequency band is high, a phase modulator combined with an interference structure can be used to realize the phase to intensity conversion; when higher linearity is required, a dual parallel MZM or push-pull structure can be used.

[0032] (2) Noise and dynamic range: Balanced detection suppresses RIN; the preamplifier adopts a low-noise transimpedance amplification structure and is matched with the full scale of the ADC; automatic gain control is introduced when necessary to expand the dynamic range.

[0033] (3) Calibration: It is recommended to build a calibration optical path (reference pulse / comb) to estimate dispersion, nonlinearity and channel mismatch parameters; the reconstruction algorithm can use least squares equalization or adaptive filtering to achieve amplitude-frequency correction.

[0034] (4) Scalability: By increasing the stretch factor M or increasing the number of parallel channels N, the measurement bandwidth or capture window can be extended while keeping the ADC specifications unchanged.

[0035] The above are merely preferred embodiments of the present invention. Any equivalent substitutions or modifications made to the structure, steps, or parameters based on the concept of the present invention shall fall within the protection scope of the present invention.

[0036] It is worth mentioning that the technical features such as the signal to be tested involved in this patent application should be regarded as prior art. The specific structure, working principle, and possible control methods and spatial arrangement of these technical features can be adopted using conventional choices in the field, and should not be regarded as the inventive point of this patent. This patent will not be further elaborated in detail.

[0037] For those skilled in the art, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A sampling front-end for an optical oscilloscope based on optical sampling electroquantization, characterized in that, It includes, in sequence, a test electrical signal input module, an optical sampling pulse generation and shaping module, an electro-optic sampling module, an optical domain mapping module, a photoelectric conversion and preamplification module, and an electric conversion and digital reconstruction module; The electrical signal input module under test is used to introduce the signal under test into the sampling front end with a specified impedance and amplitude range; The optical sampling pulse generation and shaping module is used to output an optical sampling pulse sequence with a repetition frequency, pulse width less than the corresponding preset value, and timing jitter less than the corresponding preset value. An electro-optic sampling module, including an electro-optic modulator and a bias control unit, is used to enable the optical sampling pulse sequence and the electrical signal under test to interact in the electro-optic modulator, so that the electrical signal under test modulates the intensity of the optical sampling pulse sequence, thereby generating modulated light carrying the instantaneous information of the signal under test; The bias control unit maintains the electro-optic modulator at the quadrature point to obtain an approximately linear electro-optic mapping and suppress drift; The optical domain mapping module is used to perform at least one processing on the modulated light, including dispersion broadening, optical delay scanning or wavelength division / time division multiplexing, thereby mapping the ultra-wideband signal under test into an equivalent low-speed waveform that is compatible with the electric transformer. The photoelectric conversion and preamplifier module is used to convert the mapped modulated light into an electrical signal and perform noise-optimized amplification. The electrical conversion and digital reconstruction module is used to perform analog-to-digital conversion on electrical signals and reconstruct the waveform of the signal under test according to the mapping relationship.

2. The optical oscilloscope sampling front end based on optical sampling electrochemical quantization according to claim 1, characterized in that, The optical sampling pulse generation and shaping module includes a mode-locked laser, a spectral stretcher, a dispersion compensator, and a pulse compressor, and uses optical phase-locking or optical frequency combing to stabilize the frequency and reduce timing jitter.

3. The optical oscilloscope sampling front-end based on optical sampling electrochemical quantization according to claim 1, characterized in that, The electro-optic modulator is a traveling-wave Mach-Zehnder modulator or a traveling-wave phase modulator. The electrode structure of the electro-optic modulator satisfies that the bandwidth is not less than 3 times the target measurement bandwidth, and the bias control unit is equipped with an automatic bias control function to stabilize the operating point of the electro-optic modulator.

4. The optical oscilloscope sampling front-end based on optical sampling electroquantization according to claim 1, characterized in that, The optical domain mapping module uses a dispersive medium to achieve time-stretching mapping. The stretching factor M of the time stretching satisfies M=(D1+D2) / D1, where D1 and D2 are the group delay dispersion parameters of the pre-dispersion and post-dispersion, respectively.

5. The optical oscilloscope sampling front end based on optical sampling electrochemical quantization according to claim 1, characterized in that, The optical domain mapping module uses wavelength division multiplexing and multi-channel delay lines to achieve parallel sampling, with each channel having a different relative delay. This allows for the expansion of a single capture window.

6. The optical oscilloscope sampling front end based on optical sampling electrochemical quantization according to claim 1, characterized in that, The input module for the electrical signal under test includes a switchable input interface, a programmable attenuator, a DC isolation / DC coupling selection unit, and an overvoltage protection and limiting circuit, wherein: Switchable input interfaces are used to achieve input impedance matching; The programmable attenuator enables precise adjustment of the amplitude of the signal under test. By controlling the attenuation ratio through the program, the electrical signals under test with different amplitudes are normalized to the amplitude range adapted by the electro-optic sampling module, ensuring the linearity of electro-optic modulation and the signal-to-noise ratio of the measurement. The DC isolation / DC coupling selection unit enables flexible switching of signal coupling modes to adapt to the measurement requirements of different types of electrical signals under test. When DC coupling is selected, both the DC and AC components of the signal under test are transmitted, which is suitable for scenarios where electrical signals containing DC bias need to be measured. When DC isolation is selected, the DC component in the signal is blocked, and only the AC component is transmitted, which is suitable for scenarios where only AC signals need to be measured, or where it is necessary to eliminate the influence of the DC bias of the signal under test on the operating point of the subsequent electro-optic modulator. Overvoltage protection and limiting circuits are used to limit the maximum amplitude of input signals and suppress surge signals.

7. The optical oscilloscope sampling front end based on optical sampling electrochemical quantization according to claim 1, characterized in that, The photoelectric conversion and preamplification module includes a balanced detector and a transimpedance amplifier. The balanced detector is used to suppress relative intensity noise, and the transimpedance amplifier is used to achieve bandwidth-noise matching.

8. The optical oscilloscope sampling front end based on optical sampling electrochemical quantization according to claim 1, characterized in that, The electro-quantization and digital reconstruction module includes a multi-channel interleaved ADC, a time-base calibration unit, and a digital equalization unit, wherein: The multi-channel interleaved ADC realizes analog-to-digital conversion from analog electrical signals to digital signals, and adopts a multi-channel interleaved architecture to improve the overall equivalent sampling rate through multi-channel timing interleaving, which matches the sampling requirements of ultra-wideband test signals after optical domain mapping. The timing calibration unit is used to estimate and compensate for the sampling deviation between channels based on the reference pulse or the built-in calibration tone. For deviation estimation, relying on the built-in reference pulse, it accurately detects the inherent deviations of each channel in the multi-channel interleaved ADC in terms of sampling timing, phase, and delay, as well as the timing jitter and channel mismatch errors introduced during optical domain mapping and photoelectric conversion. For deviation compensation, based on the estimated deviation data, it performs timing alignment, phase correction, and delay compensation on the sampling data of each channel in the digital domain to eliminate the problem of sampling asynchrony between channels.

9. The optical oscilloscope sampling front-end based on optical sampling electrochemical quantization according to claim 1, characterized in that, It also includes a reference clock and trigger synchronization module, which is used to align the optical sampling pulse sequence with the external trigger signal and output time stamp information for reconstructing the waveform of the signal under test.

10. An optical oscilloscope, characterized in that, It includes an optical oscilloscope sampling front end based on optical sampling electro-quantization as described in any one of claims 1-9.

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