An all-fiber integrated electro-optic crystal electric field probe and demodulation device

Abstract

This invention discloses an all-fiber integrated electro-optic crystal electric field probe and demodulation device. The electro-optic crystal electric field probe includes: a polarization-maintaining fiber, a first glass sleeve, a second glass sleeve, a collimating lens, a quarter-wave plate, an electro-optic crystal, and a reflective film. The polarization-maintaining fiber is fixedly connected to the first glass sleeve, the first glass sleeve is fixedly connected to the second glass sleeve, the polarization-maintaining fiber is connected to the collimating lens, the collimating lens is connected to the quarter-wave plate, the quarter-wave plate is connected to the electro-optic crystal, and the electro-optic crystal is connected to the reflective film. The collimating lens and the quarter-wave plate are disposed inside the second glass sleeve. This invention solves the problems of unstable electric field measurement caused by the difficulty in integrating space optical elements, susceptibility to vibration, large size, and difficulty in coupling, and improves the sensitivity and stability of the measurement device.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic field measurement technology, specifically to an all-fiber integrated electro-optic crystal electric field probe and demodulation device. Background Technology

[0002] With the advent of the 5G era, the Internet of Things (IoT), and cloud computing, the demands on processing chips are for higher speeds, wider bandwidths, and higher integration. Near-field electric field probes, especially non-destructive probes, are crucial for characterizing electromagnetic interference (EMI) and electromagnetic compatibility (EMC) performance in high-speed chip design, and are essential for evaluating device reliability. On the other hand, electrostatic discharge (EDS) and excessive electrical stress (EOS) on electronic systems are significant causes of device damage and performance degradation. Therefore, developing highly sensitive, high spatial resolution micro-electric field sensors is extremely important for improving the detection efficiency of related micro-devices and ensuring their safe operation.

[0003] Traditional electric field measurement methods utilize electrical metal probes, whose frequency response is typically resonant, supporting a standing wave structure. This non-flat frequency response leads to localization in the measurement of broadband signals and in the detection of highly integrated 5G high-speed chips. Furthermore, the metal probe's scattering and coupling with the near-field electric field being measured result in low measurement fidelity, introducing significant uncertainty into the measured electric field. The metal wires also cause distortion and disturbances in the measured field, which are related to the probe parameters and difficult to correct through subsequent generalized processing, thus resulting in measurement inaccuracies.

[0004] Optical electro-optic field sensors typically employ systems without active electronic devices or power supplies, usually using all-dielectric electro-optic crystals. Due to their inherent electromagnetic non-crosstalk characteristics, they offer significant advantages in measurement accuracy and broadband measurement capabilities. Because fiber optic networks composed of electro-optic modulators are generally metal-free, they are immune to electromagnetic interference and experience minimal disturbance to the measured electric field, resulting in a flat frequency response.

[0005] Existing reflective fiber optic electric field sensor probes and their assembly methods involve connecting the probe to a collimator via an optical fiber, assembling a polarizer, electro-optic crystal, 1 / 8 wave plate, and reflector in the middle of a quartz tube, and finally sealing the quartz tube with a quartz cylinder to form a sleeve. However, such electric field sensors integrate more optical components within the probe, leading to assembly complexity and increased insertion loss. The temperature effect caused by the natural birefringence of the crystal within the probe causes system operating point drift, affecting electric field measurement, which cannot be resolved under the aforementioned configuration. Similarly, the birefringence effect caused by temperature changes in the optical fiber also contributes to the drift of the system's sensitivity operating point. Summary of the Invention

[0006] In order to overcome the defects and shortcomings of the existing technology, the present invention provides an all-fiber integrated electro-optic crystal electric field probe and demodulation device, which solves the problems of unstable electric field measurement caused by the difficulty in integration, susceptibility to vibration, large size and difficulty in coupling of space optical elements, and improves the sensitivity and stability of the measurement device.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention provides an all-fiber integrated electro-optic crystal electric field probe, comprising: a polarization-maintaining fiber, a first glass sleeve, a second glass sleeve, a collimating lens, a quarter-wave plate, an electro-optic crystal, and a reflective film;

[0009] The polarization-maintaining fiber is fixedly connected to the first glass sleeve, the first glass sleeve is fixedly connected to the second glass sleeve, the polarization-maintaining fiber is connected to the collimating lens, the collimating lens is connected to the quarter-wave plate, the quarter-wave plate is connected to the electro-optic crystal, and the electro-optic crystal is connected to the reflective film.

[0010] The collimating lens and quarter-wave plate are located inside the second glass sleeve.

[0011] As a preferred technical solution, the diameter of the first glass sleeve is larger than the diameter of the second glass sleeve.

[0012] As a preferred technical solution, a filling gap is provided between the collimating lens, the quarter-wave plate and the second glass sleeve, and the filling gap is filled with ultraviolet glue.

[0013] As a preferred technical solution, the angle between the polarization-maintaining axis of the quarter-wave plate and the polarization-maintaining fiber is 45 degrees.

[0014] As a preferred technical solution, the electro-optic crystal is any one of lithium niobate crystal, lithium tantalate crystal, zinc telluride crystal, and bismuth silicate crystal.

[0015] As a preferred technical solution, the lithium niobate crystal or lithium tantalate crystal is transversely cut to form a transverse electric field probe with a cubic shape.

[0016] This invention also provides a control method for an all-fiber integrated electro-optic crystal electric field probe, comprising the following steps:

[0017] The polarization-maintaining fiber transmits polarized light to the collimating lens, which focuses the polarized light. The polarized light then passes through a quarter-wave plate and becomes circularly polarized. The circularly polarized light passes through an electro-optic crystal whose refractive index is modulated by an electric field, resulting in different phase differences between the light in the two orthogonal polarization directions. The modulated light signal returns to the electro-optic crystal, quarter-wave plate, and collimating lens through a reflective film, and is finally output through the optical fiber.

[0018] As a preferred technical solution, the electro-optic crystal electric field probe with the above-mentioned all-fiber integrated structure also includes: a laser, a circulator, an adapter, a polarization controller, a beam splitter, a first polarization beam splitter, a second polarization beam splitter, a first photodetector, a second photodetector, a third photodetector, a fourth photodetector, and a terminal processor.

[0019] The laser is connected to the circulator, the circulator is connected to the adapter, the adapter is connected to the electro-optic crystal electric field probe through the polarization-maintaining fiber, the circulator is also connected to the polarization controller, the polarization controller is connected to the beam splitter, the beam splitter is connected to the first polarization beam splitter and the second polarization beam splitter respectively, the first polarization beam splitter is connected to the first photodetector and the second photodetector respectively, and the second polarization beam splitter is connected to the third photodetector and the fourth photodetector respectively.

[0020] Both the first photodetector and the second photodetector are connected to the terminal processor.

[0021] The present invention also provides a control method for a demodulation device of an all-fiber integrated electro-optic crystal electric field probe, comprising the following steps:

[0022] The laser generates linearly polarized light, which is then input to the electro-optic crystal electric field probe via a circulator and adapter. The circulator inputs the polarized light returned from the electro-optic crystal electric field probe to the polarization controller. The electric field under test modulates the refractive index of the electro-optic crystal through the linear electro-optic effect. The signal reflected back by the electro-optic crystal probe carries the polarization state signal modulated by the electric field.

[0023] The polarization controller adjusts the polarization state operating point of the polarization state signal. The adjusted polarization state signal enters the first polarization beam splitter and the second polarization beam splitter respectively. Both the first and second polarization beam splitters split the light into two paths. The first polarization beam splitter decomposes the light signal and performs photoelectric conversion through the first and second photodetectors. The third and fourth photodetectors convert the received light signal into an electrical signal and output the difference signal as a feedback signal to the terminal processor. The terminal processor outputs the difference signal as the electric field signal to be measured.

[0024] As a preferred technical solution, the electric field to be measured modulates the refractive index of the electro-optic crystal through the linear electro-optic effect, and the specific steps include:

[0025] The polarization-maintaining fiber transmits polarized light to a collimating lens, which focuses the polarized light. The polarized light then passes through a quarter-wave plate to become circularly polarized. This circularly polarized light then passes through an electro-optic crystal whose refractive index is modulated by an electric field, resulting in different phase differences between the light in the two orthogonal polarization directions. Specifically:

[0026]

[0027] Where ΔΦ0 represents the natural birefringence phase difference of the crystal, ΔΦ E The phase difference is denoted by the applied electric field, d represents the effective length of the polarization state through the crystal, and Δn represents the phase difference caused by the applied electric field. o and Δn e These are the differences in refractive indices of the o-ray and e-ray after the crystal is modulated by an external electric field, respectively, and λ represents the wavelength of the probe light.

[0028] The first photodetector and the second photodetector detect the optical power P1 and optical power P2 of the orthogonal electric field components, respectively, and the difference between optical power P1 and optical power P2 is used as the output P of the demodulation device. out Specifically, it is expressed as:

[0029]

[0030] Where E represents the applied electric field, and ΔK represents the sensitivity matrix of the crystal;

[0031] The third and fourth photodetectors convert the received optical signals into electrical signals, and output the differential signal between the two as a feedback signal to the terminal processor.

[0032] By detecting whether the feedback signal is zero, the static operating point is monitored. The terminal processor inputs an electrical signal to the polarization controller, which adjusts the polarization state to the optimal operating point.

[0033] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0034] (1) The present invention uses a metal-free electric field measurement probe. The probe has the advantages of high fidelity, high spatial resolution, wide detection radio frequency bandwidth, small size and strong anti-interference ability, providing extremely high measurement accuracy and fidelity, and improving measurement performance.

[0035] (2) The present invention provides a first glass sleeve and a second glass sleeve to fix the internal optical components, thereby strengthening the overall probe structure and preventing external disturbances.

[0036] (3) Each optical element in the electro-optic crystal electric field probe of the present invention is fixed by ultraviolet glue to ensure that the device has a small insertion loss.

[0037] (4) The present invention can be configured with electro-optic crystals of different sizes, lengths and shapes to best meet the sensitivity and bandwidth requirements of the electro-optic crystal probe. The electro-optic crystal electric field probe can be matched with different crystal lengths to obtain stronger electro-optic signals.

[0038] (2) The present invention adopts the technical solution of all-fiber integrated polarization state demodulation. The first polarization beam splitter and the second polarization beam splitter set up split the detection light into two mutually orthogonal linearly polarized lights, which are sent into the corresponding photodetectors respectively. One path is used to detect the polarization state and the other path is used to provide feedback signals. This solves the problem of interference from the external environment (temperature, vibration, etc.) on the sensor operating point in practical applications and improves the sensitivity and stability of the measurement. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the all-fiber integrated electro-optic crystal electric field probe of the present invention;

[0040] Figure 2 This is a schematic diagram showing the functional relationship between the electro-optic signal and the electric field amplitude when the electro-optic crystal electric field probe of the present invention is paired with different crystals of different lengths;

[0041] Figure 3 This is a schematic diagram of the demodulation device for the all-fiber integrated electro-optic crystal electric field probe of the present invention.

[0042] Among them, 101-polarization-maintaining fiber, 102-fixing adhesive, 103-first glass sleeve, 104-second glass sleeve, 105-collimating lens, 106-1 / 4 wave plate, 107-electro-optic crystal, 108-reflective film;

[0043] 201-Laser, 202-Circulator, 203-Adapter, 204-Electro-optic crystal electric field probe, 205-Terminal processor, 206-Polarization controller, 207-Beam splitter, 208-First polarization beam splitter, 209-Second polarization beam splitter, 210-First photodetector, 211-Second photodetector, 212-Third photodetector, 213-Fourth photodetector; Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0045] Example 1

[0046] like Figure 1 As shown, this embodiment provides an all-fiber integrated electro-optic crystal electric field probe that can detect the electric field amplitude and vector direction. It is provided with the following components in sequence: polarization-maintaining fiber 101, fixing adhesive 102, first glass sleeve 103, second glass sleeve 104, collimating lens 105, 1 / 4 (quarter) wave plate 106, electro-optic crystal 107, and reflective film 108.

[0047] The polarization-maintaining fiber 101 is fixedly connected to the first glass sleeve 103 by the fixing adhesive 102, and the first glass sleeve 103 is fixedly connected to the second glass sleeve 104 by the ultraviolet adhesive. The diameter of the first glass sleeve 103 is larger than the diameter of the second glass sleeve 104.

[0048] The polarization-maintaining fiber 101 is connected to the collimating lens 105, the collimating lens 105 is connected to the quarter wave plate 106, the quarter wave plate 106 is connected to the electro-optic crystal 107, and the electro-optic crystal 107 is connected to the reflective film 108.

[0049] The collimating lens 105 and the quarter wave plate 106 are disposed inside the second glass sleeve 104. The gap between the collimating lens 105, the quarter wave plate 106 and the second glass sleeve 104 is filled with ultraviolet glue to fix the collimating lens and the quarter wave plate.

[0050] In this embodiment, the polarization-maintaining fiber is used to transmit polarized light, and the first glass sleeve and the second glass sleeve are used to fix the internal optical components, thereby reinforcing the overall probe structure and preventing external disturbances.

[0051] The collimating lens collimates and focuses the probe light, the quarter-wave plate generates circularly polarized light to adjust the operating point, the electro-optic crystal is used to sense the electric field signal and modulate the polarization state of the light, and the reflective film reflects the polarized light. The whole structure constitutes a reflective probe structure.

[0052] In this embodiment, the included angle between the polarization-maintaining axes of the quarter-wave plate and the polarization-maintaining fiber is preferably 45°.

[0053] In this embodiment, each optical element inside the electro-optic crystal electric field probe is fixed with ultraviolet adhesive to ensure a small insertion loss of the device;

[0054] In this embodiment, the measurement process of the electro-optic crystal electric field probe is as follows: the collimating lens focuses the polarized light, the incident linearly polarized light passes through the quarter-wave plate inside the electric field probe and becomes circularly polarized light, the circularly polarized light passes through the electric field-sensitive material electro-optic crystal (i.e., the electro-optic crystal whose refractive index is modulated by the electric field), and the light in the two orthogonal polarization directions produces different phase differences, so its output becomes elliptically polarized light with different magnitudes and directions of the electric field signal. The modulated light signal returns to the electro-optic crystal, quarter-wave plate, collimating lens through the reflective film, and finally enters the demodulation device through the optical fiber.

[0055] In this embodiment, there are multiple options for electro-optic crystals. Different electro-optic crystals have different electro-optic coefficients, and the crystal size, length, and shape can be selected according to different requirements such as measurement dynamic range and spatial resolution.

[0056] Electro-optic crystals, based on their crystal type and tangential orientation, are categorized into transverse and longitudinal electro-optic probes. Tangential orientation, electro-optic coefficient, and size / structure determine the sensitivity and bandwidth of the electro-optic crystal probe. Depending on sensitivity requirements, electro-optic crystals of different lengths and sizes can be selected. Specific electro-optic crystal selection includes:

[0057] Lithium niobate or lithium tantalate crystals are selected. These are anisotropic crystals with a transverse X-cut orientation, serving as a transverse electric field probe. The probe is cubic in shape, with a cross-sectional size ranging from 2 to 10 mm. 2 The maximum length can reach 30mm. The electric field components of lithium niobate crystals can be measured by rotating them 90 degrees in-plane using two orthogonal axes (y-axis and z-axis directions).

[0058] Alternatively, zinc telluride (ZnTe) crystals can be used. Zinc telluride crystals are isotropic crystals with tangential properties. <111> -cut, cylindrical in shape, with a thickness of 1-5mm and a diameter of 2-10mm, capable of vector measurement;

[0059] Alternatively, bismuth silicate (BSO) crystal can be selected. Bismuth silicate crystal is an isotropic crystal and can be used tangentially. <100> -cut or <111> -cut. <100> -cut is a vertical probe. <111> When cut, it is a transverse probe, cylindrical in shape, with a thickness of 2-10mm and a diameter that can be selected between 1-5mm. It can simultaneously measure the electric field components of two axes.

[0060] like Figure 2 As shown, the electro-optic signal as a function of the electric field amplitude was obtained when different crystals of the electro-optic crystal electric field probe were paired with different crystal lengths. This indicates that under the same electric field strength, increasing the crystal length can yield a stronger electro-optic signal; and using a crystal material with a larger electro-optic coefficient can also enhance the electro-optic signal.

[0061] Example 2

[0062] like Figure 3 As shown, this embodiment provides a demodulation device for an all-fiber integrated electro-optic crystal electric field probe. It includes the electro-optic crystal electric field probe of Embodiment 1 above, labeled as electro-optic crystal electric field probe 204 in the figure, and further includes: a laser 201, a circulator 202, an adapter 203, a polarization controller 206, a beam splitter 207, a first polarization beam splitter 208, a second polarization beam splitter 209, a first photodetector 210, a second photodetector 211, a third photodetector 212, a fourth photodetector 213, and a terminal processor 205.

[0063] Among them, laser 201 is connected to circulator 202, circulator 202 is connected to adapter 203, adapter 203 is connected to electro-optic crystal electric field probe 204 through polarization-maintaining fiber, circulator 202 is also connected to polarization controller 206, polarization controller 206 is connected to beam splitter 207, beam splitter 207 is connected to first polarization beam splitter 208 and second polarization beam splitter 209 respectively, first polarization beam splitter 208 is connected to first photodetector 210 and second photodetector 211 respectively, and second polarization beam splitter 209 is connected to third photodetector 212 and fourth photodetector 213 respectively;

[0064] Both the first photodetector 210 and the second photodetector 211 are connected to the terminal processor 205;

[0065] In this embodiment, the laser generates linearly polarized light, which is input to the electric field probe via a circulator and an adapter. The circulator also inputs the polarized light returned from the electric field probe to the polarization controller. Since the electric field to be measured modulates the refractive index of the electro-optic crystal through the linear electro-optic effect, the signal reflected back from the electro-optic crystal probe carries a polarization state signal modulated by the electric field. The polarization controller is used to adjust the polarization state operating point of the polarization state signal. The adjusted polarization state signal enters the first polarization beamsplitter and the second polarization beamsplitter, respectively. Both the first and second polarization beamsplitters split the light into two paths. The first polarization beamsplitter decomposes the optical signal, which is then converted into photoelectric signals by the first and second photodetectors. The third and fourth photodetectors convert the received optical signal into an electrical signal, and the difference signal between the two is output as a feedback signal to the terminal processor. The terminal processor outputs the difference signal as the electric field signal to be measured.

[0066] In this embodiment, the phase difference between the two orthogonal electric field components of the polarized light due to the optical path difference alters the relevant information of elliptic polarization. Under the influence of an applied electric field, the phase difference between the two orthogonal electric field components is ΔΦ, where:

[0067]

[0068] Where ΔΦ0 represents the natural birefringence phase difference of the crystal, ΔΦ E Let Δn represent the phase difference caused by the applied electric field, and d represent the effective length of the polarization state through the crystal. o and Δn eLet P1 and P2 be the refractive index differences of the o-ray and e-ray respectively after the crystal is modulated by an applied electric field, and λ represent the wavelength of the probe light. Furthermore, a sensitivity matrix ΔK describing the crystal is introduced, which is proportional to the electro-optic coefficient of the material. Therefore, the phase difference between the two orthogonal electric field components of the reflected light wave is proportional to the electric field to be measured. The optical powers P1 and P2 of the orthogonal electric field components are detected respectively, and the difference between P1 and P2 is used as the output P of the demodulation device. out The output of the demodulation device can then be expressed as:

[0069]

[0070] Where E represents the applied electric field, and P1 and P2 correspond to the outputs of the first photodetector and the second photodetector, respectively;

[0071] Therefore, when the initial phase ΔΦ0 = ±π / 4 is controlled by the polarization controller, the demodulation device has maximum sensitivity, and the output of the demodulation device at this time can be expressed as:

[0072]

[0073] In practical applications, the sensor needs to operate in the linear region of the function, so the functional relationship between the output power and the applied electric field is approximately as follows:

[0074]

[0075] The third and fourth photodetectors convert the received optical signals into electrical signals, and output the differential signal between the two (P3-P4=0) as a feedback signal to the terminal processor. P3 and P4 correspond to the outputs of the third and fourth photodetectors, respectively.

[0076] When the static operating point is at the applied electric field E = 0, the device output P out =0, so by checking whether the output signal of the feedback branch is zero, the static operating point can be monitored. The static operating point of the detection branch can be adjusted by the feedback branch. At the same time, by monitoring P3-P4=0 when measuring the electric field, temperature and vibration interference can be eliminated.

[0077] In this embodiment, the polarization controller is located at the front end of the measurement branch (based on the measurement branch formed by the first polarization beam splitter, the first photodetector, and the second photodetector) and the feedback branch (based on the feedback branch formed by the second polarization beam splitter, the third photodetector, and the fourth photodetector). Adjusting the polarization controller can simultaneously affect the polarization state of both branches, adjusting the operating point to the static operating point of the device, so that the AC electric field signal is not affected by temperature, vibration, etc.

[0078] The static operating point of the demodulation device can change due to external factors such as temperature or mechanical vibration. In this embodiment, the first and second polarization beam splitters split the detection light into two mutually orthogonal linearly polarized lights, which are then sent to the corresponding photodetectors. The function of the first and second photodetectors in this embodiment is to detect the polarization state and convert the polarization state signal modulated by the electric field into a readable electrical signal. The third and fourth photodetectors in this embodiment are used for feedback signals. By checking whether the output signal of the feedback branch is zero, the static operating point can be monitored, thus monitoring whether the static operating point is drifting. The terminal processor inputs the electrical signal to the polarization controller, which adjusts the polarization state to the optimal operating point, forming a device for stable measurement through a tracking feedback control loop.

[0079] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A control method for a demodulation device of an all-fiber integrated electro-optic crystal electric field probe, characterized in that, The demodulation device of the all-fiber integrated electro-optic crystal electric field probe is equipped with an all-fiber integrated electro-optic crystal electric field probe, including: polarization-maintaining fiber, first glass sleeve, second glass sleeve, collimating lens, quarter wave plate, electro-optic crystal and reflective film. The polarization-maintaining fiber is fixedly connected to the first glass sleeve, the first glass sleeve is fixedly connected to the second glass sleeve, the polarization-maintaining fiber is connected to the collimating lens, the collimating lens is connected to the quarter-wave plate, the quarter-wave plate is connected to the electro-optic crystal, and the electro-optic crystal is connected to the reflective film. The collimating lens and the quarter-wave plate are disposed inside the second glass sleeve; It also includes: laser, circulator, adapter, polarization controller, beam splitter, first polarization beam splitter, second polarization beam splitter, first photodetector, second photodetector, third photodetector, fourth photodetector and terminal processor; The laser is connected to the circulator, the circulator is connected to the adapter, the adapter is connected to the electro-optic crystal electric field probe through the polarization-maintaining fiber, the circulator is also connected to the polarization controller, the polarization controller is connected to the beam splitter, the beam splitter is connected to the first polarization beam splitter and the second polarization beam splitter respectively, the first polarization beam splitter is connected to the first photodetector and the second photodetector respectively, and the second polarization beam splitter is connected to the third photodetector and the fourth photodetector respectively. Both the first photodetector and the second photodetector are connected to the terminal processor. Includes the following steps: The laser generates linearly polarized light, which is then input to the electro-optic crystal electric field probe via a circulator and adapter. The circulator inputs the polarized light returned from the electro-optic crystal electric field probe to the polarization controller. The electric field under test modulates the refractive index of the electro-optic crystal through the linear electro-optic effect. The signal reflected back by the electro-optic crystal probe carries the polarization state signal modulated by the electric field. The electric field to be measured modulates the refractive index of the electro-optic crystal through the linear electro-optic effect. The specific steps include: The polarization-maintaining fiber transmits polarized light to a collimating lens, which focuses the polarized light. The polarized light then passes through a quarter-wave plate to become circularly polarized. This circularly polarized light then passes through an electro-optic crystal whose refractive index is modulated by an electric field, resulting in different phase differences between the light in the two orthogonal polarization directions. Specifically: Where ΔΦ0 represents the natural birefringence phase difference of the crystal, ΔΦ E The phase difference is denoted by the applied electric field, d represents the effective length of the polarization state through the crystal, and Δn represents the phase difference caused by the applied electric field. o and Δn e These are the differences in refractive indices of the o-ray and e-ray after the crystal is modulated by an external electric field, respectively, and λ represents the wavelength of the probe light. The first photodetector and the second photodetector detect the optical power P1 and optical power P2 of the orthogonal electric field components, respectively, and the difference between optical power P1 and optical power P2 is used as the output P of the demodulation device. out Specifically, it is expressed as: Where E represents the applied electric field, and ΔK represents the sensitivity matrix of the crystal; The third and fourth photodetectors convert the received optical signals into electrical signals, and output the differential signal between the two as a feedback signal to the terminal processor. By detecting whether the feedback signal is zero, the static operating point is monitored. The terminal processor inputs an electrical signal to the polarization controller, which adjusts the polarization state to the optimal operating point. The polarization controller adjusts the polarization state operating point of the polarization state signal. The adjusted polarization state signal enters the first polarization beam splitter and the second polarization beam splitter respectively. Both the first and second polarization beam splitters split the light into two paths. The first polarization beam splitter decomposes the light signal and performs photoelectric conversion through the first and second photodetectors. The third and fourth photodetectors convert the received light signal into an electrical signal and output the difference signal as a feedback signal to the terminal processor. The terminal processor outputs the difference signal as the electric field signal to be measured.

2. The control method for the demodulation device of the all-fiber integrated electro-optic crystal electric field probe according to claim 1, characterized in that, The diameter of the first glass sleeve is larger than the diameter of the second glass sleeve.

3. The control method for the demodulation device of the all-fiber integrated electro-optic crystal electric field probe according to claim 1, characterized in that, A filling gap is provided between the collimating lens, the quarter-wave plate and the second glass sleeve, and the filling gap is filled with ultraviolet glue.

4. The control method for the demodulation device of the all-fiber integrated electro-optic crystal electric field probe according to claim 1, characterized in that, The angle between the polarization-maintaining axis of the quarter-wave plate and the polarization-maintaining fiber is 45 degrees.

5. The control method for the demodulation device of the all-fiber integrated electro-optic crystal electric field probe according to claim 1, characterized in that, The electro-optic crystal is any one of lithium niobate crystal, lithium tantalate crystal, zinc telluride crystal, or bismuth silicate crystal.

6. The control method for the demodulation device of the all-fiber integrated electro-optic crystal electric field probe according to claim 5, characterized in that, The lithium niobate crystal or lithium tantalate crystal is transversely cut to form a transverse electric field probe, which is cubic in shape.

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