High-power microwave detector with temperature self-compensation function and use method

Abstract

The invention discloses a high-power microwave detector with a temperature self-compensation function and a use method thereof, and the method comprises the steps: sensing and obtaining the phase variation of the influence of the temperature on the phase of first beam splitting light through a detection waveguide cavity structure under the electro-optical modulation effect of high-power microwaves, so as to obtain an interference light field of the first beam splitting light; through symmetrically-arranged self-compensation waveguide cavity structures, an interference light field of second beam splitting light used for compensating the phase variation in the detection waveguide cavity structure is obtained, and interference processing is performed on the output of the detection waveguide cavity structure and the output of the self-compensation waveguide cavity structures through the output waveguide cavity structure. The phase change quantity influenced by the temperature in the interference light field of the first split light is counteracted by the interference light field of the second split light, so that the problem of phase change caused by a thermo-optical effect, a thermal expansion effect and a pyroelectric effect generated in the lithium niobate material is solved; and accurate detection of high-power microwaves cannot be realized.

Description

Technical Field

[0001] The present invention relates to the field of detector technology, and in particular to a high-power microwave detector with a temperature self-compensation function and a use method thereof. Background Art

[0002] At present, electromagnetic compatibility is becoming more and more important in our daily environment, especially for defense systems and civilian infrastructure. Common electromagnetic threats are divided into nuclear electromagnetic pulses, lightning pulses, electrostatic discharges and high-power microwaves (HPM). Unlike the previous types of electromagnetic pulses, the frequency range of high-power microwaves is 0.3GHz to 300GHz, the peak power exceeds 100MW, and the average power is above 1MW. In recent years, countries represented by the United States, Russia, the United Kingdom, Sweden and India have gradually increased their research and development efforts on high-power microwave weapons. The high-power microwaves emitted by high-power microwave weapons can irradiate the target with extremely high intensity, thereby interfering, degrading, and damaging the enemy's electronic systems, which makes high-power microwaves one of the important threats to the safety of electronic equipment. Therefore, it is necessary to find a suitable method to accurately measure high-power microwaves.

[0003] In the past few decades, various effective methods have been successfully applied to HPM detection, such as diode detectors, resistive sensors, liquid calorimeters, and electroacoustic intensity meters. Unfortunately, these methods cannot simultaneously meet the requirements of high detection threshold, high bandwidth, small size, and fast response.

[0004] Compared with the above-mentioned methods, the use of the electro-optical modulation effect of lithium niobate materials for HPM measurement has the following obvious advantages: wide operating bandwidth, high power capacity, fast response time, strong anti-interference ability and small size. However, the electro-optical characteristics of lithium niobate will drift with the change of temperature, which will cause waveform distortion in severe cases and affect the accuracy of the measurement. Studies have shown that when the external temperature changes, thermo-optical effect, thermal expansion effect and pyroelectric effect will occur inside the lithium niobate material. In order to improve the reliability of the measurement results of lithium niobate high-power microwave detectors, eliminating thermo-optical effect, thermal expansion effect and pyroelectric effect is an urgent problem to be solved in this field. Summary of the invention

[0005] The present invention provides a high-power microwave detector with temperature self-compensation function and a method for using the same, so as to overcome the problem that the reliability of the measurement result of the lithium niobate high-power microwave detector is low due to the influence of the thermo-optical effect, thermal expansion effect and pyroelectric effect of the lithium niobate material on the working point drift of the high-power microwave detector.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] A high-power microwave detector with temperature self-compensation function, comprising a cascade symmetrical structure based on a straight waveguide and a Y waveguide arranged on a lithium niobate substrate;

[0008] The cascade structure includes an input waveguide cavity structure, an output waveguide cavity structure, and a detection waveguide cavity structure and a self-compensation waveguide cavity structure that are symmetrically and parallelly arranged:

[0009] The output end of the input waveguide cavity structure is connected to the input ends of the detection waveguide cavity structure and the self-compensation waveguide cavity structure respectively, and the output ends of the detection waveguide cavity structure and the self-compensation waveguide cavity structure are connected to the input end of the output waveguide cavity structure;

[0010] The input waveguide cavity structure is used to perform beam splitting processing on the received monochromatic light signal to obtain a first split light beam and a second split light beam with equal power and phase;

[0011] The detection waveguide cavity structure is used to receive the first split light beam, sense and obtain the phase change of the first split light beam affected by temperature due to the electro-optic modulation effect of high-power microwaves, and obtain the interference light field of the first split light beam according to the phase change;

[0012] The self-compensating waveguide cavity structure is used to obtain the interference light field of the second split light beam for compensating the phase change amount in the detection waveguide cavity structure according to the received second split light beam;

[0013] The output waveguide cavity structure is used to perform interference processing on the output of the detection waveguide cavity structure and the output of the self-compensation waveguide cavity structure to perform HPM measurement.

[0014] Further, the detection waveguide cavity structure includes a first Y-waveguide cavity, i.e., a beam splitter, a first straight waveguide cavity, a second straight waveguide cavity, and a second Y-waveguide cavity, i.e., a beam combiner;

[0015] The first straight waveguide cavity is arranged in parallel with the second straight waveguide cavity;

[0016] The output end of the first Y-waveguide cavity is connected to the input ends of the first straight waveguide cavity and the second straight waveguide cavity respectively, and the first Y-waveguide cavity is used to perform beam splitting processing on the first split light beam to obtain a third split light beam and a fourth split light beam with equal power / phase;

[0017] The first straight waveguide cavity is provided with a sensing module for sensing high-power microwaves;

[0018] The first straight waveguide cavity is used to receive and transmit the third sub-beam, and electro-optically modulate the optical signal of the third sub-beam based on the sensing module, and transmit the electro-optically modulated third sub-beam to the second Y waveguide cavity;

[0019] The second straight waveguide cavity is used to transmit the fourth split light beam to the second Y waveguide cavity;

[0020] The second Y-waveguide cavity is used to perform interference and beam combining processing on the light beams output by the first straight waveguide cavity and the second straight waveguide cavity, so as to obtain the interference light field of the first split light beam.

[0021] Further, the self-compensating waveguide cavity structure includes a third Y-waveguide cavity, i.e., a beam splitter, a third straight waveguide cavity, a fourth straight waveguide cavity, and a fourth Y-waveguide cavity, i.e., a beam combiner;

[0022] The third straight waveguide cavity is arranged in parallel with the fourth straight waveguide cavity;

[0023] The output end of the third Y-waveguide cavity is connected to the input ends of the third straight waveguide cavity and the fourth straight waveguide cavity respectively, and the third Y-waveguide cavity is used to perform beam splitting processing on the second split light beam to obtain a fifth split light beam and a sixth split light beam with equal power / phase;

[0024] The third straight waveguide cavity is used to transmit the fifth split light beam to the fourth Y waveguide cavity;

[0025] The fourth straight waveguide cavity is used to transmit the sixth split light beam to the fourth Y waveguide cavity;

[0026] The fourth Y-waveguide cavity is used to perform interference and beam combining processing on the light beams output by the third straight waveguide cavity and the fourth straight waveguide cavity to obtain the interference light field of the second split light beam, so as to self-compensate for the phase change in the interference light field of the first split light beam caused by the temperature influence of the lithium niobate substrate.

[0027] Further, the first straight waveguide cavity and the third straight waveguide cavity have the same structure;

[0028] The second straight waveguide cavity has the same structure as the fourth straight waveguide cavity.

[0029] A method for using a high-power microwave detector with a temperature self-compensation function specifically comprises the following steps:

[0030] S001: Acquire a monochromatic light signal emitted by a preset light source;

[0031] S002: performing beam splitting processing on the monochromatic light signal through the input waveguide cavity structure to obtain a first split light beam and a second split light beam in terms of power / phase;

[0032] S003: splitting the first split light beam through the first Y-waveguide cavity to obtain a third split light beam and a fourth split light beam with equal power and phase;

[0033] S004: receiving and transmitting the third split light beam through the first straight waveguide cavity, performing electro-optical modulation processing on the optical signal of the third split light beam based on the sensing module, and transmitting the electro-optically modulated third split light beam to the second Y waveguide cavity;

[0034] S005: transmitting the fourth split light beam to the second Y waveguide cavity through the second straight waveguide cavity;

[0035] S006: performing interference beam combining processing on the light beams output by the first straight waveguide cavity and the second straight waveguide cavity through the second Y waveguide cavity to obtain an interference light field of the first split light beam;

[0036] S007: splitting the second split light beam through the third Y-waveguide cavity to obtain a fifth split light beam and a sixth split light beam with equal power and phase;

[0037] S008: transmitting the fifth split light beam to the fourth Y waveguide cavity through the third straight waveguide cavity;

[0038] S009: transmitting the sixth split light beam to the fourth Y waveguide cavity through the fourth straight waveguide cavity;

[0039] S010: performing interference beam combining processing on the light beams outputted by the third straight waveguide cavity and the fourth straight waveguide cavity through the fourth Y waveguide cavity to obtain an interference light field of the second split light beam;

[0040] S011: performing interference processing on the interference light field of the first split light beam and the interference light field of the second split light beam through the output waveguide cavity structure to offset the phase difference caused by temperature and obtain an optical power signal;

[0041] S012: Convert the optical power signal into an electrical signal through an existing photodetection circuit to perform HPM measurement.

[0042] Furthermore, the formula for obtaining the interference light field of the first split light beam in S006 is:

[0043]

[0044] Where: j represents the complex number symbol; m 22 represents the phase change of the optical signal in the first straight waveguide cavity caused by the temperature affecting the lithium niobate substrate; m 23 The temperature affects the lithium niobate substrate, which in turn causes the phase change of the optical signal in the second straight waveguide cavity; E 25 (t) represents the interference amplitude of the light after entering the second Y waveguide cavity; E 1 represents the light amplitude of the first split beam outputted from the input waveguide cavity structure; n represents the inherent phase difference of the detection waveguide cavity structure; w represents the angular frequency of the light beam;

[0045] The formula for obtaining the interference light field of the second split beam in S010 is:

[0046]

[0047] Where: m 32represents the phase change of the optical signal in the third straight waveguide cavity caused by the temperature affecting the lithium niobate substrate; m 33 It represents the phase change of the optical signal in the fourth straight waveguide cavity caused by the temperature affecting the lithium niobate substrate; E 34 (t) represents the interference amplitude of the light after entering the fourth Y waveguide cavity; E 2 represents the optical amplitude of the second split beam output from the input waveguide cavity structure; q represents the inherent phase difference of the self-compensating waveguide cavity structure, and

[0048]

[0049] Beneficial effect: The present invention provides a high-power microwave detector with temperature self-compensation function and a method for using the detector. The detector constructs a cascade symmetrical structure based on a straight waveguide and a Y waveguide, that is, detects and obtains the phase change caused by the temperature on the phase of a first split light beam under the electro-optical modulation effect of high-power microwaves, so as to obtain the interference light field of the first split light beam. The symmetrically arranged self-compensating waveguide cavity structure is used to obtain the interference light field of the second split light beam used to compensate for the phase change in the detection waveguide cavity structure. The output waveguide cavity structure is used to perform interference processing on the output of the detection waveguide cavity structure and the output of the self-compensating waveguide cavity structure, so as to offset the phase change caused by the temperature in the interference light field of the first split light beam by the interference light field of the second split light beam, thereby eliminating the problem of phase change caused by the thermo-optical effect, thermal expansion effect and pyroelectric effect inside the lithium niobate material, thereby realizing accurate detection of high-power microwaves and greatly improving the measurement accuracy and efficiency of high-power microwaves. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0051] Figure 1 It is a structural schematic diagram of a high-power microwave detector with temperature self-compensation function of the present invention;

[0052] Figure 2 for Figure 1 The schematic cross-section diagram along the line A1-A2 in the middle structure diagram;

[0053] Figure 3 Schematic diagram of the relationship between the external temperature and the internal steady-state temperature in this embodiment;

[0054] Figure 4is a simulation diagram of the pyroelectric effect in this embodiment;

[0055] Figure 5 The present invention is a flow chart of a method for using a high-power microwave detector with a temperature self-compensation function.

[0056] In the figure: 01, lithium niobate substrate; 1, input waveguide cavity structure; 2, detection waveguide cavity structure; 21, first Y waveguide cavity; 22, first straight waveguide cavity; 23, second straight waveguide cavity; 24, sensing module; 25, second Y waveguide cavity; 3, self-compensating waveguide cavity structure; 31, third Y waveguide cavity; 32, third straight waveguide cavity; 33, fourth straight waveguide cavity; 34, fourth Y waveguide cavity; 4, output waveguide cavity structure. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] This embodiment provides a high-power microwave detector with temperature self-compensation function, such as Figure 1 to Figure 2 As shown, it includes a cascade symmetrical structure based on a straight waveguide and a Y waveguide arranged on a lithium niobate substrate 01;

[0059] In this embodiment, the lithium niobate substrate 01 is formed into a cascade symmetrical structure based on a straight waveguide and a Y waveguide through a waveguide manufacturing technology, wherein the waveguide manufacturing process adopts proton exchange, but can be extended to other manufacturing technologies, such as titanium diffusion, thin film, etc. In this embodiment, the implementation method of forming a cascade symmetrical structure surface based on a straight waveguide and a Y waveguide on the lithium niobate substrate 01 through a waveguide manufacturing technology is an existing well-known technical means, which will not be described in detail here;

[0060] The cascade structure includes an input waveguide cavity structure 1, an output waveguide cavity structure 4, and a detection waveguide cavity structure 2 and a self-compensation waveguide cavity structure 3 that are symmetrically and parallelly arranged;

[0061] The output end of the input waveguide cavity structure 1 is connected to the input ends of the detection waveguide cavity structure 2 and the self-compensation waveguide cavity structure 3 respectively, and the output ends of the detection waveguide cavity structure 2 and the self-compensation waveguide cavity structure 3 are connected to the input end of the output waveguide cavity structure 4;

[0062] The input waveguide cavity structure 1 is used to perform beam splitting processing on the received monochromatic light signal to obtain a first split light beam and a second split light beam with equal power and phase;

[0063] And the input waveguide cavity structure 1 is specifically a Y-waveguide structure as a beam splitter;

[0064] The straight waveguide cavity in this embodiment is usually made of a dielectric material with a high refractive index (such as silicon, silicon dioxide or polymer), and is surrounded by a material with a low refractive index (such as air or other medium); common cross-sectional shapes include rectangular, circular or ridged; its working principle is: when the optical signal of the split light propagates inside the waveguide, due to the difference in refractive index, it will be totally reflected at the waveguide wall, thereby being confined inside the waveguide, thereby realizing the modulated transmission of the optical signal, and the propagation mode of the straight waveguide is determined by the geometric size of the waveguide, the refractive index of the material and the working wavelength;

[0065] Y-waveguide structure: The Y-waveguide consists of an input waveguide and two output waveguides (or vice versa), and its shape is similar to the letter "Y". It is usually used to split a beam of light into two beams (beam splitter) or combine two beams of light into one beam (beam combiner). In interference processing, the Y-waveguide is usually used as a beam combiner to combine the light beams from two straight waveguides into the same output waveguide. The specific interference mechanism is: when two beams of light enter the Y-waveguide from the first straight waveguide and the second straight waveguide, they will be superimposed in the beam combining area of ​​the Y-waveguide. If the two beams of light meet the coherence conditions (same frequency and constant phase difference), they will produce interference. The result of the interference depends on the phase difference between the two beams of light:

[0066] Constructive interference: When the phase difference is an integer multiple of 2π, the light intensity increases;

[0067] Destructive interference: When the phase difference is an odd multiple of π, the light intensity decreases;

[0068] The detection waveguide cavity structure 2 is used to receive the first split light beam, sense and obtain the phase change of the first split light beam affected by temperature due to the electro-optic modulation effect of high-power microwaves, and obtain the interference light field of the first split light beam according to the phase change;

[0069] In a specific embodiment, the detection waveguide cavity structure 2 includes a first Y-waveguide cavity 21, i.e., a beam splitter, a first straight waveguide cavity 22, a second straight waveguide cavity 23, and a second Y-waveguide cavity 25, i.e., a beam combiner;

[0070] The first straight waveguide cavity 22 and the second straight waveguide cavity 23 are arranged in parallel;

[0071] The output end of the first Y-waveguide cavity 21 is connected to the input ends of the first straight waveguide cavity 22 and the second straight waveguide cavity 23 respectively, and the first Y-waveguide cavity 21 is used to perform beam splitting processing on the first split light beam to obtain a third split light beam and a fourth split light beam with equal power / phase;

[0072] The first straight waveguide cavity 22 is provided with a sensing module 24 for sensing high-power microwaves; specifically, the sensing module 24 is specifically an antenna and an electrode. In this embodiment, if there are high-power microwaves in the space, the antenna and the electrode 24 will sense the presence of the high-power microwaves, and at this time, the optical phase difference between the first straight waveguide cavity 22 and the second straight waveguide cavity 23 changes, thereby changing the power of the light beam;

[0073] The first straight waveguide cavity 22 is used to receive and transmit the third sub-beam, and electro-optically modulate the optical signal of the third sub-beam based on the sensing module 24, and transmit the electro-optically modulated third sub-beam to the second Y waveguide cavity 25;

[0074] The second straight waveguide cavity 23 is used to transmit the fourth split light beam to the second Y waveguide cavity 25;

[0075] The second Y-waveguide cavity 25 is used to perform interference beam combining processing on the light beams output by the first straight waveguide cavity 22 and the second straight waveguide cavity 23 to obtain the interference light field of the first split light beam;

[0076] The self-compensating waveguide cavity structure 3 is used to obtain the interference light field of the second split light beam for compensating the phase change in the detection waveguide cavity structure 2 according to the received second split light beam;

[0077] In a specific embodiment, the self-compensating waveguide cavity structure 3 includes a third Y-waveguide cavity 31, i.e., a beam splitter, a third straight waveguide cavity 32, a fourth straight waveguide cavity 33, and a fourth Y-waveguide cavity 34, i.e., a beam combiner;

[0078] The third straight waveguide cavity 32 and the fourth straight waveguide cavity 33 are arranged in parallel;

[0079] The output end of the third Y-waveguide cavity 31 is connected to the input ends of the third straight waveguide cavity 32 and the fourth straight waveguide cavity 33 respectively, and the third Y-waveguide cavity 31 is used to perform beam splitting processing on the second split light beam to obtain a fifth split light beam and a sixth split light beam with equal power / phase;

[0080] The third straight waveguide cavity 32 is used to transmit the fifth split light beam to the fourth Y waveguide cavity 34;

[0081] The fourth straight waveguide cavity 33 is used to transmit the sixth split light beam to the fourth Y waveguide cavity 34;

[0082] The fourth Y waveguide cavity 34 is used to perform interference beam combining processing on the light beams output by the third straight waveguide cavity 32 and the fourth straight waveguide cavity 33, and obtain the interference light field of the second split light beam, so as to self-compensate the phase change amount in the interference light field of the first split light beam caused by the temperature influence of the lithium niobate substrate;

[0083] The output waveguide cavity structure 4 is used to perform interference processing on the output of the detection waveguide cavity structure 2 and the output of the self-compensation waveguide cavity structure 3 to perform HPM measurement, and the output waveguide cavity structure 4 is specifically a Y-waveguide structure as a beam combiner.

[0084] In this embodiment, when the temperature changes, the detection waveguide cavity structure 2 and the self-compensation waveguide cavity structure 3 are only different in the antenna and the electrode 24. The first straight waveguide cavity 22, the third straight waveguide cavity 32 and the second straight waveguide cavity 23, the fourth straight waveguide 33 have different widths and lengths, and the first straight waveguide cavity 22 has the same structure as the third straight waveguide cavity 32, and the second straight waveguide cavity 23 has the same structure as the fourth straight waveguide 33. The phase changes caused by the thermo-optical effect and the thermal expansion effect of the respective identical waveguide cavities are equal to ensure that the thermo-optical effect and the thermal expansion effect are eliminated. After entering the second Y waveguide cavity, the interfering light power changes less due to the pyroelectric effect within a certain temperature change range. At this time, the influence of the pyroelectric effect can be further eliminated through the output waveguide cavity structure 4. At this time, when high-power microwaves exist in the space, the antenna and electrode 24 in the detection waveguide cavity structure 2 will sense the presence of high-power microwaves, and the light beam transmitted in the first straight waveguide cavity 22 will undergo an electro-optical modulation effect with the high-power microwaves sensed by the antenna and electrode 24. The phase of the light beam transmitted in the first straight waveguide cavity 22 will be affected. The phase difference caused by temperature remains unchanged. At this time, the phase of the light beam transmitted in the first straight waveguide cavity 22 in the detection waveguide cavity structure 2 is only related to the high-power microwaves sensed by the antenna and electrode 24. Due to the presence of high-power microwaves, the phase difference will change, and the optical power will change after interference. The size of the external high-power microwave is determined by the change in optical power, thereby realizing HPM measurement.

[0085] In a specific embodiment, the first straight waveguide cavity 22 has the same structure as the third straight waveguide cavity 32, and the second straight waveguide cavity 23 has the same structure as the fourth straight waveguide cavity 33, that is, the first straight waveguide cavity 22 has the same length and width as the third straight waveguide cavity 32, and the second straight waveguide cavity 23 has the same length and width as the fourth straight waveguide cavity 33, which ensures the consistency of the phase difference of the optical signal obtained by the interference of the second Y waveguide cavity 25 under the influence of temperature and the phase difference of the optical signal obtained by the interference of the fourth Y waveguide cavity 34, and facilitates the offset of the phase difference caused by the influence of temperature through the output waveguide cavity structure 4, thereby realizing the function of temperature self-compensation.

[0086] A method for using a high-power microwave detector with a temperature self-compensation function, such as Figure 5 As shown, the specific steps include:

[0087] S001: Acquire a monochromatic light signal emitted by a preset light source;

[0088] S002: performing beam splitting processing on the monochromatic light signal through the input waveguide cavity structure 1 to obtain a first split light beam and a second split light beam in terms of power / phase;

[0089] S003: splitting the first split light beam through the first Y-waveguide cavity 21 to obtain a third split light beam and a fourth split light beam with equal power and phase;

[0090] S004: receiving and transmitting the third split light beam through the first straight waveguide cavity 22, performing electro-optical modulation processing on the optical signal of the third split light beam based on the sensing module 24, and transmitting the electro-optically modulated third split light beam to the second Y waveguide cavity 25;

[0091] S005: transmitting the fourth split light beam to the second Y waveguide cavity 25 through the second straight waveguide cavity 23;

[0092] S006: performing interference beam combining processing on the light beams output by the first straight waveguide cavity 22 and the second straight waveguide cavity 23 through the second Y waveguide cavity 25 to obtain an interference light field of the first split light beam;

[0093] Specifically, the formula for obtaining the interference light field of the first split light beam is:

[0094]

[0095] Where: j represents the complex number symbol; m 22 represents the phase change of the optical signal in the first straight waveguide cavity 22 caused by the temperature affecting the lithium niobate substrate 01; m 23 The temperature affects the lithium niobate substrate 01, which in turn causes the phase change of the optical signal in the second straight waveguide cavity 23; E 25 (t) represents the interference amplitude of the light after entering the second Y waveguide cavity 25; E 1 represents the light amplitude of the first split beam outputted by the input waveguide cavity structure 1; n represents the inherent phase difference of the detection waveguide cavity structure 2; w represents the angular frequency of the light beam, and the first straight waveguide cavity and the second straight waveguide cavity have different widths and lengths;

[0096] S007: splitting the second split light beam through the third Y-waveguide cavity 31 to obtain a fifth split light beam and a sixth split light beam with equal power and phase;

[0097] S008: Transmitting the fifth split light beam to the fourth Y waveguide cavity 34 through the third straight waveguide cavity 32;

[0098] S009: transmitting the sixth split light beam to the fourth Y waveguide cavity 34 through the fourth straight waveguide cavity 33;

[0099] S010: performing interference beam combining processing on the light beams outputted from the third straight waveguide cavity 32 and the fourth straight waveguide cavity 33 through the fourth Y waveguide cavity 34 to obtain an interference light field of the second split light beam;

[0100] Specifically, the formula for obtaining the interference light field of the second split light beam is:

[0101]

[0102] Where: m 32 represents the phase change of the optical signal in the third straight waveguide cavity 32 caused by the temperature affecting the lithium niobate substrate 01; m 33 It represents the phase change of the optical signal in the fourth straight waveguide cavity 33 caused by the temperature affecting the lithium niobate substrate 01; E 34 (t) represents the interference amplitude of the light after entering the fourth Y waveguide cavity 34; E 2 represents the light amplitude of the second split beam output by the input waveguide cavity structure 1, the third straight waveguide cavity and the fourth straight waveguide cavity have different widths and lengths; q represents the inherent phase difference of the self-compensating waveguide cavity structure 3, and

[0103]

[0104] S011: performing interference processing on the interference light field of the first split light beam and the interference light field of the second split light beam through the output waveguide cavity structure 4 to offset the phase difference caused by temperature and obtain an optical power difference signal;

[0105] S012: Convert the optical power signal into an electrical signal through an existing photodetection circuit to perform HPM measurement.

[0106] In this embodiment, since the lithium niobate high-power microwave detector will drift in its working point as the temperature changes, when the temperature changes, the drift phenomenon will occur regardless of whether there are high-power microwaves in the space;

[0107] Assuming that there is no high-power microwave in the space, the light field expression entering the detection waveguide cavity structure 2 and the self-compensation waveguide cavity structure 3 is:

[0108]

[0109] Where: E 2 (t) represents the amplitude of light entering the detection waveguide cavity structure 2; E 3 (t) represents the amplitude of light entering the self-compensating waveguide cavity structure 3; w represents the angular frequency of the light beam;

[0110] After the interference effect occurs in the second Y waveguide cavity 25 and the fourth Y waveguide cavity 34, the corresponding light field expression is:

[0111]

[0112] Since the detection waveguide 2 and the self-compensation waveguide 3 have the same corresponding parts except the antenna and the electrode 24, according to formulas (3) to (4), when the temperature remains unchanged, the corresponding m is 0, n is equal to q, and E 25 (t) and E 34 The expression of (t) is the same, which means that the light phases after interference of the second Y waveguide cavity 25 and the fourth Y waveguide cavity 34 are equal, and the phase difference is 0; when the temperature changes, m 22 Equal to m 32 , m 23 Equal to m 33 , n is equal to q, E 25 (t) and E 34 The expression of (t) is still the same, which means that the optical phases after interference with the second Y waveguide cavity 25 and the fourth Y waveguide cavity 34 are equal, and the phase difference does not change. If the output waveguide cavity structure 4 is used for interference again, the optical power remains unchanged.

[0113] Among them Figure 3 The figure shows the relationship between the external temperature and the internal steady-state temperature. It can be seen that the internal steady-state temperature will eventually be consistent with the external temperature. When the temperature changes, the lithium niobate will produce thermo-optical effect and thermal expansion effect. The first straight waveguide cavity 22 and the third straight waveguide cavity 32, the second straight waveguide cavity 23 and the fourth straight waveguide cavity 33 are the same, that is, the length and width of the first straight waveguide cavity 22 and the third straight waveguide cavity 32 are the same, and the length and width of the second straight waveguide cavity 23 and the fourth straight waveguide cavity 33 are the same. The phase changes caused by the thermo-optical effect and the thermal expansion effect of the respective identical waveguide cavities are equal to ensure that the thermo-optical effect and the thermal expansion effect are eliminated; as shown in FIG. Figure 4 The graph shown is a pyroelectric effect. When the temperature changes, the lithium niobate material will produce a pyroelectric effect in addition to the thermo-optical effect and thermal expansion effect. Pyroelectricity generates a horizontal electrostatic field. The electric field direction inside the waveguide is the same. The first straight waveguide cavity 22 and the third straight waveguide cavity 32, the second straight waveguide cavity 23 and the fourth straight waveguide cavity 33 are respectively the same. The phase changes caused by the pyroelectric effect of the same waveguides are equal. After entering the second Y waveguide cavity, the interfering optical power changes less due to the pyroelectric effect within a certain temperature change range. At this time, the influence of the pyroelectric effect can be further eliminated through the output waveguide cavity structure 4.

[0114] Assuming that there are high-power microwaves in space, when the temperature changes, E 25 (t) and E 34The expression of (t) is no longer the same. The optical phase difference after the interference between the second Y waveguide cavity 25 and the fourth Y waveguide cavity 34 changes. If the output waveguide cavity structure 4 is used to interfere again, the optical power changes. Therefore, by designing the detection waveguide cavity structure 2 and the self-compensation waveguide cavity structure 3 with the same structure and symmetrical and parallel arrangement, when the output waveguide cavity structure 4 interferes again, the phase difference caused by temperature cancels each other. That is, this method is called temperature self-compensation in this embodiment. Then, the optical power is only related to the size of the high-power microwave in the space, thereby realizing the accurate measurement of the high-power microwave detector. By canceling the phase difference caused by temperature, the optical power is only related to the size of the high-power microwave in the space, which greatly simplifies the system complexity of the detector when it is used. When the temperature changes, any material with a working point drift characteristic can be effectively self-compensated by the method proposed in this embodiment, such as silicon, lithium tantalate, etc.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-power microwave detector with temperature self-compensation function, characterized in that: It includes a cascade symmetrical structure based on a straight waveguide and a Y waveguide arranged on a lithium niobate substrate; The cascade structure includes an input waveguide cavity structure, an output waveguide cavity structure, and a detection waveguide cavity structure and a self-compensation waveguide cavity structure that are symmetrically and parallelly arranged: The output end of the input waveguide cavity structure is connected to the input ends of the detection waveguide cavity structure and the self-compensation waveguide cavity structure respectively, and the output ends of the detection waveguide cavity structure and the self-compensation waveguide cavity structure are connected to the input end of the output waveguide cavity structure; The input waveguide cavity structure is used to perform beam splitting processing on the received monochromatic light signal to obtain a first split light beam and a second split light beam with equal power and phase; The detection waveguide cavity structure is used to receive the first split light beam, sense and obtain the phase change of the first split light beam affected by temperature due to the electro-optic modulation effect of high-power microwaves, and obtain the interference light field of the first split light beam according to the phase change; The self-compensating waveguide cavity structure is used to obtain the interference light field of the second split light beam for compensating the phase change amount in the detection waveguide cavity structure according to the received second split light beam; The output waveguide cavity structure is used to perform interference processing on the output of the detection waveguide cavity structure and the output of the self-compensation waveguide cavity structure to perform HPM measurement.

2. The high-power microwave detector with temperature self-compensation function according to claim 1, characterized in that: The detection waveguide cavity structure includes a first Y-waveguide cavity, i.e., a beam splitter, a first straight waveguide cavity, a second straight waveguide cavity, and a second Y-waveguide cavity, i.e., a beam combiner; The first straight waveguide cavity is arranged in parallel with the second straight waveguide cavity; The output end of the first Y-waveguide cavity is connected to the input ends of the first straight waveguide cavity and the second straight waveguide cavity respectively, and the first Y-waveguide cavity is used to perform beam splitting processing on the first split light beam to obtain a third split light beam and a fourth split light beam with equal power / phase; The first straight waveguide cavity is provided with a sensing module for sensing high-power microwaves; The first straight waveguide cavity is used to receive and transmit the third sub-beam, and electro-optically modulate the optical signal of the third sub-beam based on the sensing module, and transmit the electro-optically modulated third sub-beam to the second Y waveguide cavity; The second straight waveguide cavity is used to transmit the fourth split light beam to the second Y waveguide cavity; The second Y-waveguide cavity is used to perform interference and beam combining processing on the light beams output by the first straight waveguide cavity and the second straight waveguide cavity, so as to obtain the interference light field of the first split light beam.

3. The high-power microwave detector with temperature self-compensation function according to claim 2, characterized in that: The self-compensating waveguide cavity structure includes a third Y-waveguide cavity, i.e., a beam splitter, a third straight waveguide cavity, a fourth straight waveguide cavity, and a fourth Y-waveguide cavity, i.e., a beam combiner; The third straight waveguide cavity is arranged in parallel with the fourth straight waveguide cavity; The output end of the third Y-waveguide cavity is connected to the input ends of the third straight waveguide cavity and the fourth straight waveguide cavity respectively, and the third Y-waveguide cavity is used to perform beam splitting processing on the second split light beam to obtain a fifth split light beam and a sixth split light beam with equal power / phase; The third straight waveguide cavity is used to transmit the fifth split light beam to the fourth Y waveguide cavity; The fourth straight waveguide cavity is used to transmit the sixth split light beam to the fourth Y waveguide cavity; The fourth Y-waveguide cavity is used to perform interference and beam combining processing on the light beams output by the third straight waveguide cavity and the fourth straight waveguide cavity to obtain the interference light field of the second split light beam, so as to self-compensate for the phase change in the interference light field of the first split light beam caused by the temperature influence of the lithium niobate substrate.

4. The high-power microwave detector with temperature self-compensation function according to claim 3, characterized in that: The first straight waveguide cavity has the same structure as the third straight waveguide cavity; The second straight waveguide cavity has the same structure as the fourth straight waveguide cavity.

5. A method for using the high-power microwave detector with temperature self-compensation function according to any one of claims 1 to 4, characterized in that: The specific steps include: S001: Acquire a monochromatic light signal emitted by a preset light source; S002: performing beam splitting processing on the monochromatic light signal through the input waveguide cavity structure to obtain a first split light beam and a second split light beam in terms of power / phase; S003: splitting the first split light beam through the first Y-waveguide cavity to obtain a third split light beam and a fourth split light beam with equal power and phase; S004: receiving and transmitting the third split light beam through the first straight waveguide cavity, performing electro-optical modulation processing on the optical signal of the third split light beam based on the sensing module, and transmitting the electro-optically modulated third split light beam to the second Y waveguide cavity; S005: transmitting the fourth split light beam to the second Y waveguide cavity through the second straight waveguide cavity; S006: performing interference beam combining processing on the light beams output by the first straight waveguide cavity and the second straight waveguide cavity through the second Y waveguide cavity to obtain an interference light field of the first split light beam; S007: splitting the second split light beam through the third Y-waveguide cavity to obtain a fifth split light beam and a sixth split light beam with equal power and phase; S008: transmitting the fifth split light beam to the fourth Y waveguide cavity through the third straight waveguide cavity; S009: transmitting the sixth split light beam to the fourth Y waveguide cavity through the fourth straight waveguide cavity; S010: performing interference beam combining processing on the light beams outputted by the third straight waveguide cavity and the fourth straight waveguide cavity through the fourth Y waveguide cavity to obtain an interference light field of the second split light beam; S011: performing interference processing on the interference light field of the first split light beam and the interference light field of the second split light beam through the output waveguide cavity structure to offset the phase difference caused by temperature and obtain an optical power signal; S012: Convert the optical power signal into an electrical signal through an existing photodetection circuit to perform HPM measurement.

6. The method for using a high-power microwave detector with temperature self-compensation function according to claim 5, characterized in that: The formula for obtaining the interference light field of the first split beam in S006 is: Where: j represents the complex number symbol; m 22 represents the phase change of the optical signal in the first straight waveguide cavity caused by the temperature affecting the lithium niobate substrate; m 23 The temperature affects the lithium niobate substrate, which in turn causes the phase change of the optical signal in the second straight waveguide cavity; E 25 (t) represents the light amplitude of interference after entering the second Y waveguide cavity; E1 represents the light amplitude of the first split beam output from the input waveguide cavity structure; n represents the inherent phase difference of the detection waveguide cavity structure; w represents the angular frequency of the light beam; The formula for obtaining the interference light field of the second split beam in S010 is: Where: m 32 represents the phase change of the optical signal in the third straight waveguide cavity caused by the temperature affecting the lithium niobate substrate; m 33 It represents the phase change of the optical signal in the fourth straight waveguide cavity caused by the temperature affecting the lithium niobate substrate; E 34 (t) represents the light amplitude of interference after entering the fourth Y waveguide cavity; E2 represents the light amplitude of the second split beam output from the input waveguide cavity structure; q represents the inherent phase difference of the self-compensating waveguide cavity structure, and

Images