Measurement Device for Laser Transmission State in the Sea-Air Environment

Abstract

The present invention provides a measuring device for the laser transmission state in a sea-air environment, which relates to the technical field of laser transmission. The measuring device includes: an analog container for simulating the sea-air environment at sea inside the analog container based on environmental parameters; a laser for generating a first laser; a laser transmission device for introducing the first laser into the sea-air environment and adjustably reflecting the first laser multiple times in the sea-air environment to change the transmission distance of the first laser in the sea-air environment and output a second laser; a coherence device for receiving the second laser and performing coherence measurement on the second laser to obtain measurement data; the measurement data characterizes the transmission state information of the first laser in the simulated sea-air environment; a data processing device for processing the environmental parameters used to characterize the real sea-air environment at sea based on the mapping relationship between the environmental parameters and the transmission state information to obtain the transmission state information of the laser in the real sea-air environment.

Description

Technical Field

[0001] At least one embodiment of the present invention relates to the technical field of laser transmission, and more specifically to a device for measuring the laser transmission state in a sea-air environment. Background Art

[0002] During the transmission and application of lasers in the marine environment, the sea-air environment is the main factor affecting laser transmission. Factors such as gas composition, temperature, humidity, air pressure, and turbulence in the atmosphere will all affect laser transmission. For example, at the sea-air interface, there are complex forcing and feedback processes between the ocean and the atmosphere. The exchange of momentum, energy, and matter will cause phenomena such as attenuation, jitter, expansion, and scintillation of the laser beam, resulting in a decline in the signal quality at the transmission end. Regarding the research on the transmission law of lasers in the sea-air environment, the complexity of the sea-air environment has seriously hindered the progress of related research.

[0003] In order to study and optimize the laser transmission effect in the sea-air environment, in related technologies, field tests are usually carried out. However, field tests not only have high costs and long cycles, but also are difficult to control environmental conditions, resulting in poor repeatability of test results, seriously limiting the research on the laser transmission law in the sea-air environment. In addition, the laser transmission simulation in related technologies uses a one-pass method and has fewer simulation variables. In some related technologies, only the influence of air turbulence is considered. For example, by controlling the temperatures of the heating plate and the water-cooling plate to induce air into a turbulent state, the laser transmission environment is simulated. However, this simulation method has obvious limitations: on the one hand, since there are few variable factors in the simulated sea-air environment, it is difficult to fully reflect the complexity of the sea-air environment; on the other hand, the experimental results have a large degree of contingency, narrow application scope, and it is difficult to accurately study the laser transmission law in the sea-air environment. Summary of the Invention

[0004] In view of this, the present invention provides a measuring device for the laser transmission state in a sea-air environment. The above-mentioned measuring device includes: a simulation container, which is suitable for simulating the sea-air environment at sea inside the above-mentioned simulation container based on environmental parameters; a laser, configured outside the above-mentioned simulation container, which is suitable for generating a first laser; a laser transmission device, installed on the above-mentioned simulation container, which is suitable for introducing the above-mentioned first laser into the above-mentioned sea-air environment and reflectively adjusting the above-mentioned first laser multiple times in the above-mentioned sea-air environment to change the transmission distance of the above-mentioned first laser in the above-mentioned sea-air environment and output a second laser; a coherence device, configured outside the above-mentioned simulation container, which is suitable for receiving the above-mentioned second laser and measuring the coherence of the above-mentioned second laser to obtain measurement data; wherein, the above-mentioned measurement data characterizes the transmission state information of the above-mentioned first laser in the simulated sea-air environment; and a data processing device, which is suitable for processing the environmental parameters used to characterize the real sea-air environment at sea based on the mapping relationship between the above-mentioned environmental parameters and the above-mentioned transmission state information to obtain the transmission state information of the laser in the real sea-air environment; wherein, the above-mentioned mapping relationship is obtained by machine learning of multiple above-mentioned environmental parameters and multiple measurement data obtained by simulating the sea-air environment at sea based on multiple above-mentioned environmental parameters.

[0005] According to an embodiment of the present invention, the above-mentioned simulation container includes: a wave-making device, which is suitable for simulating the influence of sea waves on laser transmission by creating the flow of seawater in the above-mentioned simulation container; a turbulence device, which is suitable for simulating the influence of turbulence on laser transmission by forming turbulence in the above-mentioned seawater; a temperature adjustment component, which is suitable for adjusting the temperature, humidity and pressure of the above-mentioned sea-air environment by adjusting the temperature of the above-mentioned seawater; and a sensing device, connected to the above-mentioned data processing device and installed inside the upper part of the above-mentioned simulation container, which is suitable for real-time monitoring of the above-mentioned environmental parameters.

[0006] According to an embodiment of the present invention, the above-mentioned laser transmission device includes: a first reflector, installed outside the laser incident window on the first side wall of the above-mentioned simulation container, which is suitable for reflecting the above-mentioned first laser and incidenting it into the above-mentioned simulation container at different incident angles; a first device, installed inside the second side wall of the above-mentioned simulation container opposite to the first side wall, which is suitable for receiving the first laser from the above-mentioned first reflector and reflecting it to the above-mentioned first side wall of the above-mentioned simulation container; a second device, installed inside the above-mentioned first side wall of the above-mentioned simulation container, which is suitable for receiving the first laser from the above-mentioned first device and reflecting it; a second reflector, which is suitable for outputting the above-mentioned second laser to the above-mentioned coherence device; the above-mentioned first laser is reflected multiple times between the above-mentioned first device and the above-mentioned second device to form the above-mentioned second laser incident on the above-mentioned second reflector, and based on the distance between the above-mentioned first device and the above-mentioned second device and the above-mentioned different incident angles, multiple corresponding transmission distances of the above-mentioned first laser in the above-mentioned sea-air environment are obtained.

[0007] According to an embodiment of the present invention, the first device and the second device include a Fabry - Perot etalon.

[0008] According to an embodiment of the present invention, the coherent device includes: a first beam splitter adapted to split the second laser into a third laser and a fourth laser; an analyzer adapted to analyze the beam parameters of the third laser; a second beam splitter adapted to split the fourth laser into a fifth laser and a sixth laser; a reflection component adapted to adjust the optical path of the fifth laser; a beam combiner adapted to combine the sixth laser and the fifth laser with adjusted optical path to obtain a combined laser; and an interferometer adapted to perform coherent measurement on the combined laser.

[0009] According to an embodiment of the present invention, the reflection component adjusts the optical path difference between the sixth laser and the fifth laser with adjusted optical path by adjusting the optical path of the fifth laser until the interference fringes detected in the interferometer disappear, thereby obtaining the measurement data.

[0010] According to an embodiment of the present invention, the wave - making device drives the seawater to generate sea waves through mechanical vibration or air flow.

[0011] According to an embodiment of the present invention, the turbulence device generates turbulence in the seawater through an air flow or a water flow stirring device.

[0012] According to an embodiment of the present invention, the temperature - regulating component adjusts the temperature of the seawater through a refrigeration or heating system.

[0013] According to an embodiment of the present invention, the sensing device includes: a temperature sensor adapted to monitor the temperature of the sea - air environment in real time; a humidity sensor adapted to monitor the humidity of the sea - air environment in real time; and a pressure sensor adapted to monitor the pressure of the sea - air environment in real time.

[0014] According to an embodiment of the present invention, a simulated container is used to simulate the sea - air environment at sea, a laser transmission device is used to simulate the long - distance transmission of the first laser in the sea - air environment, a coherent device is used to perform coherence measurement on the second laser after long - distance transmission, and a data processing device is used to analyze the transmission state information in the simulated sea - air environment. The measuring device for the laser transmission state in the sea - air environment according to the embodiment of the present invention can improve the complexity and authenticity of the simulated sea - air environment by regulating the environmental parameters inside the simulated container, and can perform repeatable tests on the transmission effect analysis by changing the transmission distance of the laser in the simulated sea - air environment. Furthermore, it can enrich the sample data for machine learning of the data processing device, so as to more fully study the long - distance laser transmission effect in the sea - air environment and provide theoretical support for laying laser transmission devices in the real ocean environment. Description of the Drawings

[0015] The above and other objects, features, and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0016] Figure 1 The schematic diagram of the principle of the measuring device for the laser transmission state in the sea-air environment according to an embodiment of the present invention is shown.

[0017] Figure 2 The schematic diagram of the principle of the simulation container according to an embodiment of the present invention is shown.

[0018] Figure 3 The schematic diagram of the principle of the laser transmission device according to an embodiment of the present invention is shown.

[0019] Figure 4 The schematic diagram of the principle of the transmission of the first laser in the laser transmission device according to an embodiment of the present invention is shown.

[0020] Figure 5 The schematic diagram of the principle of the reflection of the first laser on the first reflector according to an embodiment of the present invention is shown.

[0021] Figure 6 The schematic block diagram of the principle of the coherence device according to an embodiment of the present invention is shown. Detailed Embodiments

[0022] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0023] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0024] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0025] In the case of using expressions such as "at least one of A, B, and C, etc.", generally, it should be interpreted according to the meaning that those skilled in the art usually understand this expression. For example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc. In the case of using expressions such as "at least one of A, B, or C, etc.", generally, it should be interpreted according to the meaning that those skilled in the art usually understand this expression. For example, "a system having at least one of A, B, or C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.

[0026] It should also be noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "rear", "left", "right", etc., are only references to the directions in the accompanying drawings and are not used to limit the protection scope of the present invention. Throughout the accompanying drawings, the same elements are represented by the same or similar reference numerals. When it may cause confusion in the understanding of the present invention, the conventional structures or configurations will be omitted.

[0027] Figure 1 The schematic diagram of the principle of the measuring device for the laser transmission state in the sea-air environment according to an embodiment of the present invention is shown.

[0028] As Figure 1 shown, the measuring device for the laser transmission state in the sea-air environment includes a simulation container 1, a laser 2, a laser transmission device 3, a coherence device 4, and a data processing device 5.

[0029] According to an embodiment of the present invention, the simulation container 1 is adapted to simulate the sea-air environment on the sea inside the simulation container 1 based on environmental parameters. The laser 2 is arranged outside the simulation container 1 and is adapted to generate a first laser. The laser transmission device 3 is installed on the simulation container 1 and is adapted to introduce the first laser into the sea-air environment and adjustably reflect the first laser multiple times in the sea-air environment to change the transmission distance of the first laser in the sea-air environment and output a second laser. The coherence device 4 is arranged outside the simulation container 1 and is adapted to receive the second laser and perform coherence measurement on the second laser to obtain measurement data; wherein, the measurement data characterizes the transmission state information of the first laser in the simulated sea-air environment. The data processing device 5 is adapted to process the environmental parameters for characterizing the real sea-air environment on the sea based on the mapping relationship between the environmental parameters and the transmission state information to obtain the transmission state information of the laser in the real sea-air environment; wherein, the mapping relationship is obtained by machine learning of multiple environmental parameters and multiple measurement data obtained by simulating the sea-air environment based on multiple environmental parameters.

[0030] In one example, the environmental parameters inside the simulation container 1 can be the temperature, humidity, pressure, etc. of the sea-air environment.

[0031] According to an embodiment of the present invention, the data processing device 5 is connected to the simulation container 1 to control and monitor environmental parameters. The data processing device 5 is connected to the laser 2 to adjust the beam parameters of the first laser. The data processing device 5 is connected to the laser transmission device 3 to adjust and monitor the transmission distance. The data processing device 5 is connected to the coherence device 4 to obtain measurement data. The data processing device 5 can collect relevant data in real time to be used as sample data for machine learning.

[0032] According to an embodiment of the present invention, the sea-air environment at sea is simulated using a simulation container, the long-distance transmission of the first laser in the sea-air environment is simulated through the laser transmission device, the coherence measurement of the second laser after long-distance transmission is performed through the coherence device, and the transmission state information in the simulated sea-air environment is analyzed through the data processing device. The measurement device for the laser transmission state in the sea-air environment according to the embodiment of the present invention can improve the complexity and authenticity of the simulated sea-air environment by regulating the environmental parameters inside the simulation container, and can perform tests on the repeatable transmission effect analysis by changing the transmission distance of the laser in the simulated sea-air environment, thereby enriching the sample data for the data processing device to perform machine learning, and thus can more fully study the long-distance laser transmission effect in the sea-air environment, providing a theoretical support for laying a laser transmission device in a real marine environment.

[0033] According to an embodiment of the present invention, the data processing device can perform machine learning on multiple environmental parameters and multiple measurement data obtained by simulating the sea-air environment based on multiple environmental parameters by constructing a machine learning model, and establish a mapping relationship between the environmental parameters and the transmission state information.

[0034] In the measurement device for the laser transmission state in the sea-air environment according to the embodiment of the present invention, environmental parameters such as the humidity and temperature of the sea-air environment are collected in real time as sample data for machine learning.

[0035] During the machine learning process, the environmental parameters and measurement data of the sea-air environment collected are preprocessed and feature extracted to provide high-quality sample data input for the model training of machine learning. Based on a large-scale sample data set, a machine learning model is constructed. For example, the machine learning model can be a random forest, a support vector machine, a deep neural network, etc. A mapping relationship between the time coherence of the laser after long-distance transmission and the environmental parameters is established. Through cross-validation and model evaluation, using indicators such as R² (coefficient of determination), RMSE (root mean square error), etc., the model hyperparameters and structure are optimized to accurately quantify the influence relationship of environmental parameters on the transmission state information. The optimal machine learning model is selected to simulate the laser transmission characteristics under different sea-air environmental parameters, and based on the phase compensation or adaptive optical correction optimization scheme, the anti-interference ability and stability of the laser transmission system established in the real sea-air environment are improved, and further the transmission efficiency of the laser transmission system is enhanced.

[0036] Figure 2 The schematic principle diagram of a simulation container according to an embodiment of the present invention is shown.

[0037] As Figure 2 shown, the simulation container 1 includes a wave-making device 6, a turbulence device 7, a temperature adjustment component 8, and a sensing device 9.

[0038] According to an embodiment of the present invention, the wave-making device 6 is adapted to simulate the influence of ocean waves on laser transmission by creating the flow of seawater in the simulation container 1. The turbulence device 7 is adapted to simulate the influence of turbulence on laser transmission by forming turbulence in the seawater. The temperature adjustment component 8 is adapted to adjust the temperature, humidity, and pressure of the sea-air environment by adjusting the temperature of the seawater. The sensing device 9 is connected to a data processing device and is installed inside the upper part of the simulation container 1, and is adapted to monitor environmental parameters in real time.

[0039] As Figure 2 shown, in one example, the simulation container 1 further includes a housing 11 and seawater 12. The housing 11 can be a specially made corrosion-resistant housing. The housing 11 can be a cuboid formed by stainless steel plates. The seawater 12 can be brine conforming to the salt concentration of the simulated sea area.

[0040] As Figure 2 shown, in one example, the simulation container 1 further includes a laser incident window 13 and a laser exit window 14.

[0041] According to an embodiment of the present invention, factors affecting the sea-air environment are simulated by a simulation container, such as the salinity, air pressure, temperature, humidity, and tides of different seawaters. A wave-making device and a turbulence device are used to generate sea waves and turbulence to simulate the influence of various climate environments on laser transmission. The sensing device can integrate multiple sensors to real-time monitor key parameters such as gas composition, salinity, temperature, humidity, and air pressure inside the simulation container, ensuring precise control of the experimental simulated sea-air environment.

[0042] Figure 3 The schematic diagram of the principle of the laser transmission device according to an embodiment of the present invention is shown.

[0043] As Figure 3 shown, the laser transmission device includes a first reflector 31, a first device 32, a second device 33, and a second reflector 34.

[0044] As Figure 1 , Figure 2 , Figure 3 shown, according to an embodiment of the present invention, the first reflector 31 is installed outside the laser incident window 13 on the first side wall 101 of the simulation container 1, and is suitable for reflecting the first laser and incidenting it into the interior of the simulation container 1 at different incident angles. The first device 32 is installed inside the second side wall 102 of the simulation container 1 opposite to the first side wall 101, and is suitable for receiving the first laser from the first reflector and reflecting it to the first side wall 101 of the simulation container 1. The second device 33 is installed inside the first side wall 101 of the simulation container 1, and is suitable for receiving the first laser from the first device 32 and reflecting it. The second reflector 34 is suitable for outputting the second laser to the coherent device 4.

[0045] According to an embodiment of the present invention, the first laser is reflected multiple times between the first device 32 and the second device 33 to form the second laser incident on the second reflector. Based on the distance between the first device 32 and the second device 33 and different incident angles, multiple corresponding transmission distances of the first laser in the sea-air environment are obtained.

[0046] As Figure 3 shown, according to an embodiment of the present invention, the first device 32 and the second device 33 can be Fabry-Perot etalons (F-P etalons).

[0047] Figure 4 The schematic diagram of the principle of the transmission of the first laser in the laser transmission device according to an embodiment of the present invention is shown.

[0048] As Figure 2 , Figure 3 and Figure 4As shown, in one example, the first device 32 and the second device 33 form a Fabry - Perot etalon cavity (F - P etalon cavity). The first reflector 31 may include a first mirror 311 and a first reflection controller 312, and the second reflector 34 may include a second mirror 341 and a second reflection controller 342. The first mirror 311 reflects the first laser 21. The first laser 21 enters the simulation container 1 from the laser incident window 13 and is incident on the first device 32. The first laser 21 reflects back and forth between the first device 32 and the second device 33. By controlling the first mirror 311 through the first reflection controller 312, the incident angle of the first laser 21 incident on the first device 32 is adjusted. Based on the distance between the first device 32 and the second device 33 and different incident angles , a plurality of corresponding transmission distances of the first laser in the sea - air environment are obtained. By controlling the second mirror 341 through the second reflection controller 342, the output direction of the second laser 41 is adjusted to be incident on the coherence device.

[0049] In one example, the first mirror 311 and the second mirror 341 may be mirrors coated with a high - reflection film for the first laser wavelength.

[0050] Figure 5 The schematic diagram of the reflection principle of the first laser on the first reflector according to the embodiment of the present invention is shown.

[0051] As Figure 4 , Figure 5 shown, in one example, when the direction of the first laser 21 emitted by the laser is parallel to the first device 32, the angle between the first laser 21 and the first mirror 311 when the first laser 21 is incident on the first mirror 311 is , then the angle between the first laser reflected by the first mirror 311 and the first mirror 311 is still . According to the geometric relationship, the incident angle of the first laser reflected by the first mirror 311 incident on the Fabry - Perot etalon cavity (F - P etalon cavity) can be expressed as shown in the following formula (1):

[0052] (1).

[0053] The transmission distance of the first laser reflected by the first mirror 311 after multiple reflections in the Fabry - Perot etalon cavity (F - P etalon cavity) can be expressed as shown in the following formula (2):

[0054] (2);

[0055] wherein, Denotes the length of the first device 32 in a Fabry - Perot etalon cavity (F - P etalon cavity). Denotes the distance between the first device 32 and the second device 33 in a Fabry - Perot etalon cavity (F - P etalon cavity).

[0056] According to an embodiment of the present invention, the laser transmission device utilizes an F - P etalon to achieve multiple reflections of the laser, and can also precisely control the transmission path and distance of the laser.

[0057] Figure 6 Shows a schematic block diagram of a coherent device according to an embodiment of the present invention.

[0058] As Figure 6 shown, the coherent device includes a first beam splitter 42, an analyzer 43, a second beam splitter 44, a reflection component 45, a beam combiner 46, and an interferometer 47.

[0059] According to an embodiment of the present invention, the first beam splitter 42 is adapted to split the second laser 41 to obtain a third laser and a fourth laser. The analyzer 43 is adapted to analyze the beam parameters of the third laser. The second beam splitter 44 is adapted to split the fourth laser to obtain a fifth laser and a sixth laser. The reflection component 45 is adapted to adjust the optical path of the fifth laser. The beam combiner 46 is adapted to combine the sixth laser and the fifth laser with adjusted optical path to obtain a combined laser. The interferometer 47 is adapted to perform coherent measurement on the combined laser.

[0060] In one example, the analyzer 43 can measure parameters such as the spot size, shape, and intensity distribution of the beam of the third laser.

[0061] According to an embodiment of the present invention, the reflection component 45 adjusts the optical path difference between the sixth laser and the fifth laser with adjusted optical path by adjusting the optical path of the fifth laser until the interference fringes detected in the interferometer 47 disappear, and obtains measurement data.

[0062] As Figure 6As shown, in one example, the reflection component 45 may include a third mirror 451, a fourth mirror 452, and a guide rail 453. After the fifth laser is sequentially reflected by the third mirror 451 and the fourth mirror 452, it can be incident on the beam combining mirror 46. The third mirror 451 and the fourth mirror 452 can be mounted on the guide rail 453, and the guide rail 453 can together adjust the distance between the third mirror 451 and the fourth mirror 452 and the beam combining mirror 46 to adjust the optical path of the fifth laser. Based on the optical path difference between the sixth laser and the fifth laser with the adjusted optical path, the phase differences of the two beams of light in the combined laser are different, and equal inclination interference will occur, generating interference fringes. By elongating the optical path of the fifth laser through the guide rail 453, when the optical path difference between the sixth laser and the fifth laser with the adjusted optical path is greater than the coherence length of the equal inclination interference, the interference fringes will disappear.

[0063] For lasers in the order of MHz linewidth, it is difficult to measure the spectral linewidths of the first laser and the third laser using ordinary spectrometers. By measuring the coherence time of the first laser and the coherence time of the third laser, and comparing the coherence time of the first laser with that of the third laser, the change in the transmission state information of the first laser in the simulated sea-air environment can be observed.

[0064] According to an embodiment of the present invention, the coherence length of the third laser or the coherence time characterizes the temporal coherence of the third laser. The coherence length is proportional to the square of the central wavelength of the third laser and inversely proportional to the source linewidth of the third laser, and can be expressed as shown in the following formula (3):

[0065] (3);

[0066] Wherein, is the speed of light, is the central wavelength of the third laser, is the full width at half maximum of the spectral linewidth of the third laser, is a constant to be determined (its specific value is determined by the spectral shape of the third laser, Gaussian line shape ).

[0067] Use the guide rail to adjust the optical path of the fifth laser to adjust the optical path difference between the sixth laser and the fifth laser with the adjusted optical path. Based on the change in the optical path difference, observe and record the visibility of the interference fringes (for example, use a CCD camera to read the intensity of the interference fringes). Increase the optical path difference until the visibility of the interference fringes drops to 1 / e of the maximum value (or set other thresholds according to experimental needs). Record the optical path difference value at this time, and this optical path difference value is the coherence length of the third laser .

[0068] According to an embodiment of the present invention, the coherence device utilizes optical elements such as beam splitters and beam combiners, combined with a guide rail and an analyzer for beam parameters, to achieve precise measurement of the temporal coherence of a laser.

[0069] According to an embodiment of the present invention, the wave-making device can generate ocean waves by mechanical vibration or air flow to drive seawater.

[0070] In one example, the wave-making device may include a motor, a piston, a transmission shaft, and a push plate, etc. The motor can serve as the power source of the wave-making device, providing rotational power to drive the entire wave-making device. The piston can be the direct recipient of the power source, capable of converting the rotational motion of the motor into a linear reciprocating motion. Driven by the motor, the piston moves back and forth along a specific path. The transmission shaft can be a key component connecting the motor and the piston, capable of transmitting the rotational power of the motor to the piston to ensure smooth power transmission. The push plate can be a component directly in contact with seawater, capable of pushing the water body of seawater through the linear reciprocating motion of the piston to simulate the formation of waves. The reciprocating motion of the piston is transmitted to the push plate through the transmission shaft, causing the push plate to generate a periodic thrust on the water surface, thereby forming waves.

[0071] According to an embodiment of the present invention, after the motor is started, the rotational power is transmitted to the piston through the transmission shaft. Driven by the motor, the piston performs a linear reciprocating motion, and the linear reciprocating motion is transmitted to the push plate through the transmission shaft. The push plate generates a thrust on the water surface, simulating the effect of waves. Through the wave-making device, the simulation device can simulate the influence of ocean waves on laser transmission, can generate different degrees of ocean waves, simulate the real ocean surface, change the laser transmission environment, and provide an experimental basis for studying the propagation characteristics of lasers in the ocean environment.

[0072] According to an embodiment of the present invention, the turbulence device can generate turbulence in seawater through an air flow or water flow stirring device.

[0073] In one example, the turbulence device may include an adjustable fan and an air compressor. By adjusting the air compressor, fan speed, and direction, different turbulence effects can be simulated.

[0074] Turbulence can cause the expansion and distortion of a laser beam, resulting in the degradation of beam quality. The transmission of a laser in ocean turbulence leads to a complex law of beam expansion and a relatively cumbersome calculation process. Parameters such as the kinetic energy dissipation rate and temperature difference dissipation rate of turbulence affect the characteristics of laser transmission. For example, turbulence changes caused by temperature and salinity affect the transmission path and energy distribution of the laser.

[0075] According to an embodiment of the present invention, the temperature adjustment component can adjust the temperature of seawater through a refrigeration or heating system.

[0076] In one example, the temperature control component may include a heating plate, a cooling plate, and a temperature compensation plate. The heating plate may be disposed at the bottom of the simulation container and may be an electric heating plate. When it is necessary to increase the temperature of the sea-air environment, the heating plate will be activated. The heating plate can generate heat through a resistance heating wire to heat the air or seawater inside the simulation container to simulate the laser transmission effect in a high-temperature environment. The cooling plate may be disposed at the top of the simulation container, opposite to the heating plate. When it is necessary to lower the temperature of the sea-air environment, the cooling plate can intervene. The cooling plate can adopt a water-cooling technology to absorb and transfer the heat of the device simulation container through circulating cooling water, thereby reducing the temperature to simulate the transmission characteristics of the laser in a low-temperature environment. The temperature compensation plate may be a material with good thermal conductivity (thin copper plate) for promoting the more uniform and stable distribution of the heat or cold generated by the heating plate and the cooling plate inside the simulation container. The temperature compensation plate can quickly respond to temperature changes and assist in adjusting the local temperature difference inside the simulation container through its thermal conductivity characteristics to ensure the temperature uniformity of the entire sea-air environment.

[0077] In one example, the working process of the temperature control component may be as follows: when heating is required, the heating plate is activated to generate heat. The temperature compensation plate quickly absorbs and evenly distributes the heat to ensure that the temperature of the sea-air environment rises quickly and evenly. When cooling is required, the cooling plate is activated to absorb heat through the water-cooling system. The temperature compensation plate assists in evenly transferring the cold to the entire sea-air environment to achieve rapid and uniform cooling. In the entire working process of the temperature control component, the temperature compensation plate acts as an intermediary, not only promoting the uniform distribution of heat and cold, but also helping to reduce temperature fluctuations and improve the stability and accuracy of temperature control.

[0078] According to an embodiment of the present invention, the sensing device may include: a temperature sensor suitable for real-time monitoring of the temperature of the sea-air environment; a humidity sensor suitable for real-time monitoring of the humidity of the sea-air environment; and a pressure sensor suitable for real-time monitoring of the pressure of the sea-air environment.

[0079] In one example, the sensing device may further include a gas analyzer and a salinometer.

[0080] The measurement method of the measurement device for the laser transmission state in the sea-air environment will be described below through an embodiment.

[0081] Measure the laser transmission effect in the simulation container in the sea-air environment. The measurement method may include the following operating steps.

[0082] According to the preset scenario, substances for simulating environmental variables are added into the simulation container. For example, seawater with a certain salt content is added; after heating, dry ice is put in, and a large amount of water mist can be formed in a short time; a fan and a wave-making device can be used to simulate the atmospheric flow and the changes on the ocean surface; a pressure regulator and a temperature control device can be used to adjust the air pressure, temperature, and humidity in the simulation container.

[0083] According to the monitoring of the changes in the environmental parameters in the simulation container by the sensing device, when the environmental parameters reach the indicators and are relatively stable, a laser transmission experiment is carried out.

[0084] A full-band reflector can be used to make the first laser to be measured with a preset divergence angle incident on the F-P cavity at a predetermined incident angle, and through multiple back-and-forth reflections, the reliability of the experimental results can be ensured. The transmission distance can be controlled by controlling the angle of the first reflector. After multiple transmissions, the second laser is emitted from the exit window of the F-P cavity (the laser exit window of the simulation container), and the simulation of long-distance transmission in the sea-air environment is completed.

[0085] The temporal coherence of the second laser is measured outside the laser exit window. The interference fringes can be made to disappear by pulling the guide rail away, and the optical path difference at this time is recorded. The coherence length and coherence time can be obtained through calculation, and the temporal coherence can be obtained.

[0086] During the experiment, through various precision sensors, the input data of the collected environmental parameters are transmitted to the data processing device in real time and accurately, such as a computer system. The machine learning model is used to deeply process and analyze the sample data. Through multiple iterative learning and data accumulation, a complex and delicate mapping relationship between the temporal coherence of the laser and various environmental parameters is gradually established.

[0087] It should be noted that in the attached drawings shown in the embodiments of the present invention, blue represents the color of seawater, and the red line segment with an arrow represents the laser beam.

[0088] The embodiments of the present invention have been described above. However, these embodiments are only for illustrative purposes and not for limiting the scope of the present invention. Although the embodiments have been described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Without departing from the scope of the present invention, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present invention.

Claims

1. A measuring device for the laser transmission state in a sea-air environment, characterized in that, The measurement device includes: An analog container adapted to simulate the sea-air environment at sea inside the analog container based on environmental parameters; A laser configured outside the analog container and adapted to generate a first laser; A laser transmission device mounted on the analog container and adapted to introduce the first laser into the sea-air environment and reflect the first laser adjustably multiple times in the sea-air environment to change the transmission distance of the first laser in the sea-air environment and output a second laser; A coherence device configured outside the analog container and adapted to receive the second laser and perform coherence measurement on the second laser to obtain measurement data; wherein the measurement data characterizes the transmission state information of the first laser in the simulated sea-air environment; and A data processing device adapted to process the environmental parameters for characterizing the real sea-air environment at sea based on the mapping relationship between the environmental parameters and the transmission state information to obtain the transmission state information of the laser in the real sea-air environment; wherein the mapping relationship is obtained by performing machine learning on multiple of the environmental parameters and multiple measurement data obtained by simulating the sea-air environment at sea based on multiple of the environmental parameters; The analog container includes: A wave-making device adapted to simulate the influence of sea waves on laser transmission by creating the flow of seawater in the analog container; A turbulence device adapted to simulate the influence of turbulence on laser transmission by forming turbulence in the seawater; A temperature adjustment component adapted to adjust the temperature, humidity, and pressure of the sea-air environment by adjusting the temperature of the seawater; and A sensing device connected to the data processing device and mounted inside the upper part of the analog container and adapted to monitor the environmental parameters in real time.

2. The measuring device according to claim 1, characterized in that, The laser transmission device includes: A first reflector mounted outside the laser incident window on the first side wall of the analog container and adapted to reflect the first laser and incident it into the interior of the analog container at different incident angles; A first device mounted inside the second side wall of the analog container opposite to the first side wall and adapted to receive the first laser from the first reflector and reflect it to the first side wall of the analog container; A second device mounted inside the first side wall of the analog container and adapted to receive the first laser from the first device and reflect it; A second reflector adapted to output the second laser to the coherence device; The first laser is reflected multiple times between the first device and the second device to form the second laser incident on the second reflector, and based on the distance between the first device and the second device and the different incident angles, multiple corresponding transmission distances of the first laser in the sea-air environment are obtained.

3. The measuring device according to claim 2, characterized in that, The first device and the second device include Fabry-Perot etalons.

4. The measuring device according to claim 1, characterized in that, The coherence device includes: A first beam splitter adapted to split the second laser to obtain a third laser and a fourth laser; An analyzer adapted to perform beam parameter analysis on the third laser; The second beam splitter is adapted to split the fourth laser beam to obtain a fifth laser beam and a sixth laser beam; The reflection component is adapted to adjust the optical path of the fifth laser beam; The beam combiner is adapted to combine the sixth laser beam and the fifth laser beam with adjusted optical path to obtain a combined laser beam; The interferometer is adapted to perform coherent measurement on the combined laser beam.

5. The measuring device according to claim 4, characterized in that The reflection component adjusts the optical path difference between the sixth laser beam and the fifth laser beam with adjusted optical path by adjusting the optical path of the fifth laser beam until the interference fringes detected in the interferometer disappear, so as to obtain the measurement data.

6. The measuring device according to claim 1, characterized in that, The wave-making device drives the seawater to generate sea waves through mechanical vibration or air flow.

7. The measuring device according to claim 1, characterized in that, The turbulence device generates turbulence in the seawater through an air flow or a water flow stirring device.

8. The measuring device according to claim 1, characterized in that, The temperature adjustment component adjusts the temperature of the seawater through a refrigeration or heating system.

9. The measuring device according to claim 1, characterized in that The sensing device includes: A temperature sensor adapted to monitor the temperature of the sea-air environment in real time; A humidity sensor adapted to monitor the humidity of the sea-air environment in real time; A pressure sensor adapted to monitor the pressure of the sea-air environment in real time.

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