A stealth coding and anti-interference laser encoding and decoding system based on sub-pulse phenomenon

Abstract

The present invention belongs to the field of stealth coding and anti-interference technology, and is particularly directed to a stealth coding and anti-interference laser encoding and decoding system based on the sub-pulse phenomenon, comprising a laser emission module, a signal processing module, and a pulse information comparison unit. The present invention generates a main pulse and a sub-pulse with a preset double-peak interval through a passive Q-switched laser, coordinates the double-pulse timing using a main pulse signal delay, performs differential gain amplification on the main pulse and the sub-pulse, reconstructs the double-peak interval information through electrical signal synthesis, compares the actual interval with the preset coding information, and implements an anti-interference function. Laser stability is ensured through a side pumping structure combined with a temperature compensation mechanism, and the stealth coding characteristics of the double-peak interval are utilized to enhance the concealment and anti-deception capabilities of the encoding and decoding signal. The system has the advantages of high anti-interference, dynamically adjustable coding, and strong environmental adaptability, and can effectively solve the problem of traditional laser signals being easily intercepted or interfered with.

Description

Technical Field

[0001] The present invention relates to the field of laser encoding and decoding and anti-interference technology, and in particular to a stealth coding and anti-interference laser encoding and decoding system based on sub-pulse phenomenon. Background Art

[0002] Laser encoding and decoding technology, which enables precise target location by encoding laser signals, plays a key role in laser encoding and decoding, drone navigation, and reconnaissance. However, encoded and decoded laser signals are susceptible to active interference from the enemy or complex environmental noise, resulting in reduced encoding and decoding accuracy or even failure. Therefore, the reliability of anti-interference encoding technology has become a core challenge.

[0003] Currently, mainstream anti-jamming methods rely primarily on single-pulse energy coding or fixed-frequency modulation. For example, coding schemes based on pulse amplitude modulation use a preset energy threshold to distinguish target signals from jammers; while pulse repetition frequency coding utilizes a fixed-interval sequence to transmit encoding and decoding information. However, these methods rely on static coding rules, which can be quickly deciphered by the enemy through spectrum analysis or energy interception. They also lack the ability to adapt to dynamic environmental disturbances, such as atmospheric turbulence and high-speed target motion.

[0004] The static nature of single-pulse coding in traditional technologies makes it incapable of handling complex electromagnetic interference. For example, fixed-frequency modulation is easily overwhelmed by high-repetition-rate jammers, while amplitude coding is susceptible to background noise contamination. Existing systems also lack compensation for signal propagation delay drift, leading to cumulative time deviations between the preset code and the actual received signal, severely reducing codec reliability. Furthermore, the dynamic attenuation of reflected signals from high-speed targets and changes in the optical path further exacerbate the difficulty of code matching.

[0005] In recent years, some research has attempted to improve stealth by utilizing dual-pulse interval coding, transmitting coded information through the time interval between the main pulse and the sub-pulse. However, existing schemes have significant drawbacks: dual-pulse intervals often use fixed ranges or pseudo-random sequences, making the coding pattern susceptible to statistical analysis; signal processing relies on software algorithms to analyze the intervals, resulting in high latency (>10ms) in anti-interference decision-making; and the system fails to account for dynamic interval deviations caused by laser temperature drift or pump fluctuations, lacking real-time compensation capabilities.

[0006] Currently, there is an urgent need for a laser encoding and decoding solution that combines dynamic anti-interference capabilities, high concealment, and environmental adaptability. To this end, this paper proposes a stealth encoding and anti-interference system based on the passive Q-switched sub-pulse phenomenon. Through dynamic encryption and real-time compensation of the double-pulse interval, this system addresses the issues of easy cracking, delayed anti-interference, and environmental sensitivity inherent in traditional technologies. Summary of the Invention

[0007] (1) Technical problems solved

[0008] In view of the deficiencies in the prior art, the present invention provides a stealth coding and anti-interference laser encoding and decoding system based on the sub-pulse phenomenon, which solves the problems raised in the above background technology.

[0009] (2) Technical solution

[0010] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0011] A stealth coding and anti-interference laser encoding and decoding system based on sub-pulse phenomenon, comprising: a laser emission system, a signal processing system and a pulse information comparison unit;

[0012] The laser emission system includes a fully reflective mirror M1, a Nd:YAG crystal, a passive Q switch, an output mirror M2, a pulse interval adjustment and signal transmission module, an LD pump array, an LD pump power module, a temperature acquisition module, and a pulse width compensator.

[0013] The signal processing system includes: a photoelectric signal converter, a main pulse signal delay device, a main pulse gain amplifier, a sub-pulse gain amplifier, and a main-sub pulse electrical signal synthesizer.

[0014] The laser emission system adopts a side-pumping structure, in which a total reflection mirror M1 is located at the rear end of the laser emission system, and an Nd:YAG crystal is immediately in front of the total reflection mirror M1; a passive Q switch and an output mirror M2 are arranged in sequence along the optical path to form a resonant cavity; an LD pump array surrounds the side of the Nd:YAG crystal, and an LD pump power module is electrically connected to the LD pump array and is located at the bottom of the laser emission system; a temperature acquisition module is installed on the side surface of the Nd:YAG crystal and is connected to a pulse width compensator through a feedback circuit.

[0015] The pulse interval adjustment and signal sending module is integrated into the control end of the laser emission system and connected to the passive Q switch through a high-speed communication interface, and is used to preset and adjust the double-peak interval information of the main pulse and the sub-pulse.

[0016] The signal processing system is located at the front end of the optical path output direction of the laser emission system; the photoelectric signal converter is installed at the input end of the signal processing system and is aligned with the optical path of the laser emission system; the main pulse signal delayer is adjacent to the output end of the photoelectric signal converter, the main pulse gain amplifier and the sub-pulse gain amplifier are respectively connected to the main pulse signal delayer through independent circuits, and the main-sub pulse electrical signal synthesizer is located at the rear end of the main pulse gain amplifier and the sub-pulse gain amplifier.

[0017] The pulse information comparison unit is connected to the master-sub pulse electrical signal synthesizer via a data line.

[0018] Optionally, the passive Q switch uses a saturable absorber material Cr 4+:YAG, initial transmittance 30%-70%; recovery time <10ns, modulation depth 5%-30%.

[0019] Optionally, the photoelectric signal converter uses a PIN photodiode with a quantum efficiency greater than 80%, a dark current less than 1 nA, a response time less than 2 ns, and a wavelength range of 400-1100 nm;

[0020] Optionally, the main pulse gain amplifier and the sub-pulse gain amplifier adopt a differential amplifier circuit structure, the main pulse gain amplifier has a dynamic range of 20-60dB, the sub-pulse gain amplifier has a dynamic range of 10-40dB, and the gain difference between the two is ≥15dB; the bandwidth covers 100MHz to 3GHz.

[0021] Optionally, the pulse width compensator adopts a digital PID controller with a response time of <10μs and a compensation accuracy of ±0.1ns;

[0022] Optionally, the master-sub pulse electrical signal synthesizer adopts time domain interleaving technology and improves the bimodal interval measurement resolution to ≤100ps and the sampling rate to ≥2GS / s through an interpolation algorithm.

[0023] Optionally, the LD pump array adopts wavelength locking technology to stabilize the pump wavelength within the range of 808.5nm±0.2nm through a volume Bragg grating (VBG).

[0024] Optionally, the pulse information comparison unit integrates a chaotic encryption algorithm to perform nonlinear transformation encryption on the preset bimodal interval information, with a key update frequency greater than 100 Hz. Equipped with a digital correlator, the comparison speed is greater than 1M times / second, and the tolerance threshold can be set within the range of ±5%-±20%.

[0025] Optionally, the temperature acquisition module uses a distributed fiber Bragg grating sensor, with 5-20 temperature measurement points arranged along the axial direction of the Nd:YAG crystal, and a spatial resolution of <2 mm.

[0026] Optionally, the main pulse signal delay device adopts programmable delay line (PDL) technology, supporting precise delay adjustment in 0.1ns steps, jitter <5ps RMS, delay accuracy ±0.5ns, and maximum delay of 50ns.

[0027] Optionally, the output mirror M2 adopts a thermal deformation compensation design, and a piezoelectric ceramic actuator is integrated on the back of the lens to dynamically adjust the curvature radius according to temperature changes, with a compensation range of ±0.5mm.

[0028] Optionally, the laser emission system integrates a beam pointing stabilization device, including a fast tilt mirror (FSM) and a position sensitive detector (PSD), with a pointing stabilization accuracy of <5μrad.

[0029] Optionally, the pulse interval adjustment and signal sending module adopts a cascade structure of an acousto-optic modulator (AOM) and an electro-optic modulator (EOM) to achieve precise control of the pulse interval in the range of 0.1ns-100μs.

[0030] Optionally, the signal processing system is equipped with an adaptive filter group, which can automatically suppress the background light interference frequency band and improve the signal-to-noise ratio by >20dB.

[0031] Optionally, the LD pump power module adopts a constant current drive mode with a current stability of <±0.5% and a pulse rise time of <5μs; it integrates a pulse shaping function, supports three pump waveforms: trapezoidal wave, Gaussian wave, and square wave, and the rise / fall edge can be adjusted in the range of 1-50μs.

[0032] Optionally, the pulse information comparison unit is equipped with a deep learning accelerator and uses a convolutional neural network (CNN) to identify the time-frequency domain features of the interference pulse, with an error rate of <0.1%.

[0033] Optionally, the main pulse gain amplifier adopts automatic gain control (AGC) technology to dynamically adjust the gain coefficient according to the input signal strength, and the dynamic range is extended to 80dB.

[0034] (3) Beneficial effects

[0035] Compared with the prior art, the present invention provides a stealth coding and anti-interference laser encoding and decoding system based on the sub-pulse phenomenon, which has the following beneficial effects:

[0036] The present invention generates preset interval coding features of the main pulse and sub-pulse through the sub-pulse characteristics of the passively Q-switched laser, and uses a differentiated gain amplification strategy to perform signal enhancement of the main pulse and sub-pulse at different rates, forming a composite coding structure with dual encryption in time domain and amplitude. The interference signal cannot synchronously reproduce the dynamic gain difference and the interval rules of encryption evolution, resulting in a significant deviation between the actual interval information and the preset code, thereby improving the anti-interference recognition capability.

[0037] Through temperature compensation closed-loop control, the impact of ambient temperature fluctuations on pulse timing is offset in real time to ensure the stability of the coding interval. The main pulse delay control and the synthesizer work together to achieve high-precision signal reconstruction. Combined with the intelligent recognition algorithm, repetitive interference patterns are actively filtered, maintaining high reliability in complex electromagnetic environments.

[0038] Through the collaborative innovation of dynamic coding rules, differentiated signal enhancement and environmental adaptive technology, the problem of traditional laser encoding and decoding being single and easy to be intercepted and simulated has been solved, and the anti-interference capability and encoding and decoding accuracy in battlefield environments have been significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 2. An optical path diagram of a stealth coding and anti-interference laser encoding and decoding system based on the sub-pulse phenomenon according to an embodiment of the present invention;

[0040] Figure 2 The figure is a technical flow chart of a stealth coding and anti-interference laser encoding and decoding system based on sub-pulse phenomenon according to an embodiment of the present invention.

[0041] In the figure, the structural components indicated by each reference numeral are: 1. laser emission system; 2. fully reflective mirror M1; 3. Nd:YAG crystal; 4. passive Q switch; 5. output mirror M2; 6. pulse interval adjustment and signal sending module; 7. LD pump array; 8. LD pump power module; 9. temperature acquisition module; 10. pulse width compensator; 11. signal processing system; 12. photoelectric signal converter; 13. main pulse signal delay; 14. main pulse gain amplifier; 15. sub-pulse gain amplifier; 16. main-sub pulse electrical signal synthesizer; 17. pulse information comparison unit. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 making creative efforts are within the scope of protection of the present invention.

[0043] Example

[0044] like Figure 1-2 As shown, an embodiment of the present invention proposes a stealth coding and anti-interference laser encoding and decoding system based on the sub-pulse phenomenon:

[0045] like Figure 1 The laser emitting system 1 includes a laser emitting system 1, a signal processing system 11, and a pulse information comparison unit 17. The laser emitting system 1 includes a full-reflection mirror M1 2; 2, an Nd:YAG crystal 3, a passive Q switch 4, an output mirror M25, a pulse interval adjustment and signal transmission module 6, an LD pump array 7, an LD pump power module 8, a temperature acquisition module 9, and a pulse width compensator 10. The signal processing system 11 includes an optical-to-electrical signal converter 12, a main pulse signal delay 13, a main pulse gain amplifier 14, a sub-pulse gain amplifier 15, and a main-sub pulse electrical signal synthesizer 16, wherein:

[0046] The laser emission system 1 adopts a side-pumping structure, wherein a total reflection mirror M12 is located at the rear end of the laser emission system 1, and an Nd:YAG crystal 3 is immediately in front of the total reflection mirror M12; a passive Q switch 4 and an output mirror M25 are arranged in sequence along the optical path to form a resonant cavity; an LD pump array 7 surrounds the side of the Nd:YAG crystal 3, and an LD pump power module 8 is electrically connected to the LD pump array 7 and is located at the bottom of the laser emission system 1; a temperature acquisition module 9 is installed on the side surface of the Nd:YAG crystal 3 and is connected to a pulse width compensator 10 through a feedback circuit;

[0047] The pulse interval adjustment and signal transmission module 6 is integrated into the control end of the laser emission system 1 and is connected to the passive Q switch 4 through a high-speed communication interface, and is used to preset and adjust the double-peak interval information of the main pulse and the sub-pulse;

[0048] The signal processing system 11 is located at the front end of the optical path output direction of the laser emitting system 1; the photoelectric signal converter 12 is installed at the input end of the signal processing system 11 and is aligned with the optical path of the laser emitting system 1; the main pulse signal delayer 13 is adjacent to the output end of the photoelectric signal converter 12, the main pulse gain amplifier 14 and the sub-pulse gain amplifier 15 are respectively connected to the main pulse signal delayer 13 through independent circuits, and the main-sub pulse electrical signal synthesizer 16 is located at the rear end of the main pulse gain amplifier 14 and the sub-pulse gain amplifier 15.

[0049] The pulse information comparison unit 17 is connected to the master-sub pulse electrical signal synthesizer 16 via a data line.

[0050] Optionally, the passive Q switch 4 uses a saturable absorber material including Cr 4+ :YAG, initial transmittance 35%; recovery time 5ns, modulation depth 15%.

[0051] Optionally, the photoelectric signal converter 12 uses a PIN photodiode with a quantum efficiency of 90%, a dark current of 0.5 nA, a response time of 1 ns, and a wavelength range of 400-1100 nm;

[0052] Optionally, the main pulse gain amplifier 14 and the sub-pulse gain amplifier 15 adopt a differential amplifier circuit structure, the main pulse gain amplifier 14 has a dynamic range of 20-60dB, the sub-pulse gain amplifier 15 has a dynamic range of 10-40dB, and the gain difference between the two is ≥15dB; the bandwidth covers 100MHz to 3GHz.

[0053] Optionally, the pulse width compensator 10 adopts a digital PID controller with a response time of <10 μs and a compensation accuracy of ±0.1 ns;

[0054] Optionally, the master-sub pulse electrical signal synthesizer 16 adopts time domain interleaving technology and improves the bimodal interval measurement resolution to ≤100ps and the sampling rate to ≥2GS / s through an interpolation algorithm.

[0055] Optionally, the LD pump array 7 adopts wavelength locking technology to stabilize the pump wavelength within the range of 808.5 nm ± 0.2 nm through a volume Bragg grating (VBG).

[0056] Optionally, the pulse information comparison unit 17 integrates a chaotic encryption algorithm to perform nonlinear transformation encryption on the preset bimodal interval information, with a key update frequency greater than 100 Hz. It is equipped with a digital correlator, with a comparison speed greater than 1M times / second, and a tolerance threshold that can be set within a range of ±5%-±20%.

[0057] Optionally, the temperature acquisition module 9 uses a distributed fiber Bragg grating sensor, with 5-20 temperature measurement points arranged along the axial direction of the Nd:YAG crystal, and a spatial resolution of less than 2 mm.

[0058] Optionally, the main pulse signal delayer 13 adopts programmable delay line (PDL) technology, supports precise delay adjustment in 0.1ns steps, jitter <5psRMS, delay accuracy ±0.5ns, and maximum delay of 50ns.

[0059] Optionally, the output mirror M2 5 adopts a thermal deformation compensation design, and a piezoelectric ceramic actuator is integrated on the back of the lens to dynamically adjust the curvature radius according to temperature changes, with a compensation range of ±0.5mm.

[0060] Optionally, the laser emission system 1 integrates a beam pointing stabilization device, including a fast tilt mirror (FSM) and a position sensitive detector (PSD), with a pointing stabilization accuracy of <5 μrad.

[0061] Optionally, the pulse interval adjustment and signal sending module 6 adopts a cascade structure of an acousto-optic modulator (AOM) and an electro-optic modulator (EOM) to achieve precise control of the pulse interval in the range of 0.1ns-100μs.

[0062] Optionally, the signal processing system 11 is equipped with an adaptive filter bank, which can automatically suppress background light interference frequency bands, and improve the signal-to-noise ratio by >20dB.

[0063] Optionally, the LD pump power module 8 adopts a constant current drive mode with a current stability of <±0.5% and a pulse rise time of <5μs; it integrates a pulse shaping function, supports three pump waveforms: trapezoidal wave, Gaussian wave, and square wave, and the rise / fall edge can be adjusted in the range of 1-50μs.

[0064] Optionally, the pulse information comparison unit 17 is equipped with a deep learning accelerator and uses a convolutional neural network (CNN) to identify the time-frequency domain features of the interference pulse, with an error rate of <0.1%.

[0065] Optionally, the main pulse gain amplifier 14 adopts automatic gain control (AGC) technology to dynamically adjust the gain coefficient according to the input signal strength, and the dynamic range is extended to 80dB.

[0066] Another aspect of the present invention provides a stealth coding anti-interference laser encoding and decoding method based on the sub-pulse phenomenon, the method comprising:

[0067] The periodic switching action of the passive Q switch 4 excites the main pulse and the accompanying sub-pulses in the resonant cavity; the pulse interval adjustment and signal transmission module 6 dynamically sets the double-peak interval between the main pulse and the sub-pulse based on a preset coding rule, forming a time-domain stealth feature; the LD pump array 7 injects energy into the Nd:YAG crystal 3 using a side pumping method, while the temperature acquisition module 9 monitors the crystal thermal state in real time and dynamically compensates the pump power through the pulse width compensator 10 to ensure the temporal stability of the laser output; the preset double-peak interval information is transmitted to the pulse information comparison unit 17 via an encrypted communication link for storage as a benchmark data for subsequent anti-interference verification;

[0068] The emitted laser pulse sequence is converted into an electrical signal by the photoelectric signal converter 12. The main pulse signal delay device 13 controls the timing of the main pulse to decouple it from the gain amplification processing timing of the sub-pulse. The main pulse gain amplifier 14 implements high-magnification amplification on the main pulse, and the sub-pulse gain amplifier 15 adopts a differentiated gain strategy to ensure that the amplitude characteristics of the main pulse and the sub-pulse are consistent. The main-sub-pulse electrical signal synthesizer 16 synchronizes the two signals in the time domain and superimposes the waveforms to reconstruct an electrical signal with a complete double-peak interval characteristic and extracts the actual interval information for subsequent analysis.

[0069] The pulse information comparison unit 17 performs multi-level anti-interference verification: first, a time domain correlation analysis is performed on the reconstructed bimodal interval, and by calculating the time matching degree with the preset coding information, valid signals that meet the dynamic tolerance threshold are screened out; for signals that fail to match, an interference marking mechanism is triggered and signal tracing analysis is started;

[0070] The closed-loop control system composed of the temperature acquisition module 9 and the pulse width compensator 10 offsets the pulse time jitter caused by crystal temperature fluctuations in real time. The LD pump power module 8 adopts an adaptive constant current mode, combined with a crystal thermal lens effect compensation algorithm, to maintain the spatial uniformity of the pump energy. The coordinated control of the main pulse signal delay 13 and the gain amplifiers 14 / 15 ensures the consistency of the time domain accuracy and amplitude characteristics of the bimodal interval encoding.

[0071] The pulse interval adjustment and signal transmission module 6 periodically updates the bimodal interval coding rule according to the preset encryption algorithm, and combines the timing offset strategy of the main pulse signal delay 13 to achieve the time domain dynamic evolution of the coding characteristics. The differential amplification ratio of the main pulse and sub-pulse gain amplifiers 14 / 15 is synchronously adjusted, and a second layer of encryption features is superimposed on the amplitude dimension to form a composite coding structure with time domain and amplitude dual encryption, which significantly improves the anti-interception and anti-cracking capabilities of the encoded and decoded signals.

[0072] The first-level verification is based on the time domain matching analysis of the bimodal interval to quickly filter out interference signals that significantly deviate from the preset range; the second-level verification identifies abnormal energy distribution of the imitation signal through the amplitude ratio characteristic analysis of the main pulse and the sub-pulse; the pulse information comparison unit 17 integrates a pattern recognition algorithm to perform feature learning and active shielding on the continuous occurrence of fixed-interval repeated attack signals; when complex multi-source interference is detected, the adaptive signal reconstruction algorithm is activated to extract effective coding features from the mixed signal to ensure the reliability of the encoding and decoding instructions and adaptability to the battlefield environment.

[0073] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A stealth coding and anti-interference laser encoding and decoding system based on sub-pulse phenomenon, characterized in that: include: Laser emission system (1), signal processing system (11) and pulse information comparison unit (17); The laser emission system (1) includes a full-reflection mirror M1 (2), an Nd:YAG crystal (3), a passive Q switch (4), an output mirror M2 (5), a pulse interval adjustment and signal transmission module (6), an LD pump array (7), an LD pump power module (8), a temperature acquisition module (9), and a pulse width compensator (10); The laser emission system (1) adopts a side pumping structure, wherein the Nd:YAG crystal (3) is located immediately in front of the full reflective mirror M1 (2); the passive Q switch (4) and the output mirror M2 (5) are sequentially arranged along the optical path to form a resonant cavity; the LD pump array (7) is mounted around the surface of the Nd:YAG crystal (3); the LD pump power module (8) is electrically connected to the LD pump array (7); the temperature acquisition module (9) is mounted on the side surface of the Nd:YAG crystal (3) and is connected to the pulse width compensator (10) via a feedback circuit; the pulse width compensator (10) is electrically connected to the LD pump power module (8); The pulse interval adjustment and signal transmission module (6) is integrated into the control end of the laser emission system (1), and is connected to the passive Q switch (4) via a high-speed communication interface, and is used to preset and adjust the double-peak interval information of the main pulse and the sub-pulse; The signal processing system (11) includes a photoelectric signal converter (12), a main pulse signal delay device (13), a main pulse gain amplifier (14), a sub-pulse gain amplifier (15), and a main-sub pulse electrical signal synthesizer (16); The signal processing system (11) is located at the front end of the optical path output direction of the laser emission system (1); The photoelectric signal converter (12) is installed at the input end of the signal processing system (11) and is aligned with the optical path of the laser emission system (1); the main pulse signal delay device (13) is adjacent to the output end of the photoelectric signal converter (12); the sub-pulse gain amplifier (15) is electrically connected to the main pulse signal delay device (13); and the main pulse gain amplifier (14) and the sub-pulse gain amplifier (15) are both electrically connected to the main-sub-pulse electrical signal synthesizer (16); The pulse information comparison unit (17) is connected to the master-sub pulse electrical signal synthesizer (16) via a data line.

2. The invisible coding and anti-interference laser encoding and decoding system based on the sub-pulse phenomenon according to claim 1 is characterized by: The doping concentration of the Nd:YAG crystal (3) is 0.6%-1.2%, and the length is 20-50 mm; the passive Q switch (4) adopts Cr 4 ⁺: YAG crystal, initial transmittance 30%-70%; the temperature acquisition module (9) is a patch type thermocouple, with a measurement accuracy of ±0.5°C, forming a closed loop control with the pulse width compensator (10), with a compensation range of ±5ns / °C; the output mirror M2 (5) has a transmittance of 20%-40% and a curvature radius of 100-300mm.

3. The invisible coding and anti-interference laser encoding and decoding system based on the sub-pulse phenomenon according to claim 1 is characterized by: The LD pump array (7) has an emission wavelength of 808nm±3nm, a peak power of 100-500W, and a pulse width of 100-300μs; the pulse width compensator (10) adopts a digital PID controller with a response time of less than 10μs and a compensation accuracy of ±0.1ns; the pulse interval adjustment and signal transmission module (6) has a continuously adjustable interval range of 0.1-10μs, and an adjustment step length of ≤10ns.

4. The invisible coding and anti-interference laser encoding and decoding system based on the sub-pulse phenomenon according to claim 1 is characterized in that: The photoelectric signal converter (12) is a photodiode with a response time of less than 2 ns and a wavelength range of 400-1100 nm. The main pulse gain amplifier (14) has a dynamic range of 20-60 dB, and the sub-pulse gain amplifier (15) has a dynamic range of 10-40 dB, and the gain difference between the two is ≥15 dB. The main pulse signal delay device (13) has a delay accuracy of ±0.5 ns and a maximum delay of 50 ns.

5. The invisible coding and anti-interference laser encoding and decoding system based on the sub-pulse phenomenon according to claim 1 is characterized in that: The master-sub pulse electrical signal synthesizer (16) is implemented using a high-speed FPGA, with a sampling rate of ≥2GS / s and a time resolution of ≤100ps; the pulse information comparison unit (17) is equipped with a digital correlator, with a comparison speed of >1M times / second, and a tolerance threshold that can be set within a range of ±5%-±20%.

6. The invisible coding and anti-interference laser encoding and decoding system based on sub-pulse phenomenon according to claim 1 is characterized by: The LD pump power module (8) adopts a constant current drive mode, with a current stability of less than ±0.5% and a pulse rise time of less than 5 μs; the high-speed communication interface adopts an optical fiber transmission protocol, with a data transmission rate of ≥1 Gbps and a transmission delay of less than 10 μs; the system supports a dynamic encoding mode, and can adjust the bimodal interval in real time within the range of 1-100 μs and update in 1 μs steps.

7. The invisible coding and anti-interference laser encoding and decoding system based on sub-pulse phenomenon according to claim 1 is characterized by: The first-level comparison tolerance range is ±5% of the preset interval, and the second-level verification pulse amplitude ratio is in the range of 2:1 to 10:1; the pulse information comparison unit (17) integrates a pattern recognition algorithm to identify and eliminate interference signals with a repetition interval greater than 3 times.

Images