Simulation device and method for transmission of laser signal under action of atmospheric turbulence

Abstract

The invention discloses a device and a method for simulating transmission of a laser signal under the action of atmospheric turbulence. The method comprises the following steps: a signal source generates a frequency signal; the light modulation module modulates a frequency signal into a laser signal and then emits the laser signal through the light transmitting antenna, the laser signal is transmitted through the atmospheric turbulence channel and then reaches the reflector, and the reflector reflects the laser signal and then transmits the laser signal through the atmospheric turbulence channel and then reaches the light receiving antenna; the optical receiving antenna receives a laser signal and then sends the laser signal to the optical delay module. The optical delay module carries out amplification, delay and dispersion compensation on the laser signal and then inputs the laser signal to the optical coupler. After the laser signal is transmitted for n times in a loop formed by the light transmitting antenna, the reflector, the receiving antenna and the light delay module, the laser signal is transmitted to the light receiving module; by accurately controlling the switching time of the optical switch and the length of the optical fiber, signal delay under different transmission distances can be accurately simulated, and signal transmission effects under different turbulence intensities can be effectively reproduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser transmission, and particularly relates to an analog device and method for transmission of an optical signal under the action of atmospheric turbulence. BACKGROUND

[0002] When a laser signal is transmitted in an atmospheric channel, it is mainly affected by atmospheric absorption, scattering and turbulence effects. Among them, atmospheric turbulence is the key factor restricting the transmission performance. The random spatial and temporal fluctuations of temperature, humidity and air pressure in the atmosphere will cause irregular changes in the local atmospheric refractive index, thereby forming a turbulence field. The specific effects of atmospheric turbulence on the laser signal are reflected in three aspects: first, beam jitter, the uneven refractive index causes the laser propagation direction to randomly shift, the receiving end spot position continuously shakes, and the alignment accuracy is affected; second, beam expansion, part of the light deviates from the original path due to turbulence, resulting in the expansion of the spot size and the reduction of the energy density; third, intensity flicker, after the superposition of laser light of different paths, the received light intensity presents high-frequency random fluctuations, which may cause signal interruption in severe cases. Due to the cumulative effect, it is extremely serious in the case of long propagation distance and strong turbulence, thereby restricting the performance of the laser signal in the space transmission system, so it is of great significance to accurately simulate the long-distance transmission of the laser signal under the action of atmospheric turbulence.

[0003] However, for long-distance transmission of a laser signal in the atmosphere, the existing analytical theory cannot clearly describe the optical transmission characteristics, and the long-distance laser atmospheric propagation experiment has the characteristics of uncontrollable parameters, poor repeatability, high investment cost of manpower and material resources, and great influence of environment, etc. At the same time, the transmission distance of the experimental link is limited, and the experimental test results still need to be evaluated. The existing methods for simulating long-distance transmission of a laser signal in an atmospheric turbulence channel mainly include software simulation method and experimental simulation method.

[0004] The software simulation method mainly simulates the influence of atmospheric turbulence on the transmission of a laser signal through numerical simulation. The main problems of this method are low accuracy, insufficient diversity and high complexity, and there is a certain error between the simulation system and the actual transmission result.

[0005] The experimental simulation method is to establish a controllable and limited scale artificial turbulence simulation device in the laboratory as a substitute for atmospheric turbulence. However, the limited space only has the characteristics of uniform isotropy in a small space far from the boundary. It is not rigorous to analyze the full-path light propagation effect in the turbulence simulation device using isotropic turbulence statistical theory, and usually only short-range turbulence can affect the laser signal. SUMMARY

[0006] The application provides an analog device and method for transmission of laser signals under the action of atmospheric turbulence, generates turbulence samples in a short-distance atmospheric link, and cooperates linear stable storage transmission of a fiber link with high-precision delay control to more realistically simulate the influence of long-distance atmospheric laser link strong correlation turbulence and weak correlation turbulence pairs on laser signals.

[0007] To achieve the above object, the technical scheme adopted by the application is:

[0008] The first aspect of the application provides an analog device for transmission of laser signals under the action of atmospheric turbulence, characterized in that the device comprises a signal source, an optical modulation module, an optical coupler and an optical transmitting antenna connected in sequence through optical fibers; the optical modulation transmitting module is electrically connected with a control module;

[0009] The signal source generates a frequency signal and sends it to the optical modulation module; the optical modulation module modulates the frequency signal into a laser signal under the action of the control module and sends the laser signal out through the optical transmitting antenna; the laser signal is transmitted through an atmospheric turbulence channel to a mirror, is reflected by the mirror and then transmitted through the atmospheric turbulence channel to an optical receiving antenna;

[0010] The optical receiving antenna is connected with a first optical switch input through an optical fiber; the output of the first optical switch is connected with an optical delay module and an optical receiving module through optical fibers; the first optical switch is used to switch the optical path of the optical receiving antenna to the optical delay module and the optical receiving module; the optical delay module is connected with the optical coupler through an optical fiber; the optical delay module is electrically connected with the control module;

[0011] The optical receiving antenna receives the laser signal and sends it into the optical delay module through the first optical switch; the optical delay module amplifies, delays and disperses the laser signal and then inputs the laser signal into the optical coupler; the laser signal is transmitted between the loop formed by the optical transmitting antenna, the mirror, the optical receiving antenna, the first optical switch and the optical delay module for m times to simulate the transmission characteristics of the laser signal under the action of long-distance turbulence; when the number of round trips reaches m, the laser signal is transmitted to the optical receiving module.

[0012] Further, the optical modulation module comprises a laser, a modulation signal generating unit and an optical modulation unit; the modulation signal generating unit is electrically connected with the control module;

[0013] The modulation signal generating unit generates burst modulation signals of a specific format by using the frequency signal output by the signal source; the optical modulation unit loads the burst modulation signals generated by the burst modulation signal generating unit into the laser to generate laser signals.

[0014] Furthermore, the optical delay module includes a first optical amplifier, a second optical switch, a dispersion compensator, an optical signal controller, and an optical fiber of a set length; the first optical switch and the input end of the first optical amplifier are connected via optical fiber; the first optical amplifier, the optical fiber of the set length, the dispersion compensator, and the second optical switch are sequentially connected via optical fiber; the output end of the second optical switch is connected via optical fiber to an optical coupler and the input end of the first optical amplifier; the second optical switch is used to switch the delayed loop optical path between the laser signal to the optical coupler and the laser signal to the input end of the first optical amplifier.

[0015] The input terminal of the optical signal controller is electrically connected to the control module; the output terminal of the optical signal controller is electrically connected to the optical switch and the dispersion compensator; the optical signal controller receives the control commands output by the control module and adjusts the switching direction of the optical switch according to the control commands.

[0016] Furthermore, the laser signal is sent to the input of the first optical amplifier through the second optical switch, and is amplified, delayed and dispersion compensated in a repetitive cycle inside the optical delay module to increase the delay time of the laser signal.

[0017] Furthermore, the optical receiving module includes a second optical amplifier and an optical demodulation and signal recovery unit connected in sequence via optical fibers; the second optical amplifier is connected to the first optical switch via optical fibers.

[0018] Furthermore, the distance between the optical transmitting antenna and the optical receiving antenna is greater than 100m.

[0019] A second aspect of the present invention provides a control method for a simulation device of laser signal transmission under atmospheric turbulence, characterized in that it includes:

[0020] The signal source is controlled to generate a frequency signal, which is then sent to the optical modulation module; the frequency signal is modulated into a laser signal and emitted through the optical transmitting antenna.

[0021] The laser signal is transmitted through the atmospheric turbulence channel and then reaches the reflector. The reflector reflects the laser signal and then transmits it through the atmospheric turbulence channel to the optical receiving antenna.

[0022] When the optical receiving antenna receives the laser signal and sends it into the optical delay module, the laser signal is sent to the input terminal of the first optical amplifier through the second optical switch. It is amplified, delayed and dispersion compensated by repeating the loop inside the optical delay module. After the laser signal is repeated h times inside the optical delay module, it is sent to the optical transmitting antenna through the optical coupler.

[0023] The laser signal is transmitted m times between the optical transmitting antenna, the reflector, the optical receiving antenna, the first optical switch and the optical delay module to simulate the transmission characteristics of the laser signal under long-distance turbulence. When the number of round-trip transmissions reaches m, the laser signal is transmitted to the optical receiving module.

[0024] When the optical signal delay time in the delay module is extremely short (e.g., below microseconds), it can simulate the effect of laser signal transmission under strong correlation long-distance turbulence; when the optical signal delay time in the delay module is relatively long (e.g., on the order of milliseconds), it can simulate the effect of laser signal transmission under weak correlation long-distance turbulence.

[0025] Furthermore, the optical modulation module includes a laser, a modulation signal generation unit, and an optical modulation unit; the control module controls the modulation signal generation unit to generate a burst modulation signal of a specific format using the frequency signal output from the signal source; ;in, This indicates the round-trip time delay of the laser signal in the atmosphere. This indicates the propagation delay of the laser signal in the optical fiber of the optical delay module;

[0026] The optical modulation unit loads the burst modulation signal generated by the burst modulation signal generation unit onto the laser to generate a laser signal.

[0027] Furthermore, the formula for calculating the round-trip transmission delay of a laser signal in the atmosphere is:

[0028] ;

[0029] In the formula, Indicates the number of loops. This represents the transmission distance from the optical transmitting antenna or optical receiving antenna to the reflector, where c is the speed of light.

[0030] Furthermore, the formula for calculating the transmission delay of the laser signal in the optical fiber of the optical delay module is as follows:

[0031] ;

[0032] In the formula, Indicates the fiber transmission distance in the fiber delay loop. is the refractive index in the optical fiber.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] The signal source of the present invention generates a frequency signal and sends it to the optical modulation module; the optical modulation module modulates the frequency signal into a laser signal under the action of the control module and then transmits it through the optical transmitting antenna. The laser signal is transmitted through the atmospheric turbulence channel and reaches the reflector. The reflector reflects the laser signal and then transmits it through the atmospheric turbulence channel to the optical receiving antenna. By forming a cyclical round-trip transmission path through the reflector, the signal transmission effect under different turbulence intensities can be effectively reproduced, while greatly improving the flexibility and repeatability of the experiment.

[0035] The optical receiving antenna of this invention receives a laser signal and sends it to an optical delay module. The optical delay module amplifies, delays, and compensates for dispersion before inputting the laser signal to an optical coupler. The laser signal is transmitted n times between the optical transmitting antenna, reflector, optical receiving antenna, first optical switch, and optical delay module to simulate the transmission characteristics of the laser signal under long-distance turbulence. After n round trips, the laser signal is transmitted to the optical receiving module. When the optical signal delay time in the delay module is extremely short (e.g., below microseconds), it can simulate the effect of laser signal transmission under strongly correlated long-distance turbulence; when the optical signal delay time in the delay module is relatively long (e.g., on the order of milliseconds), it can simulate the effect of laser signal transmission under weakly correlated long-distance turbulence. By precisely controlling the switching timing of the optical switch and the fiber length, high-precision delay control can be achieved; it can accurately simulate signal delay at different transmission distances, avoid signal conflicts, and ensure the accuracy and reliability of experimental results. Attached Figure Description

[0036] Figure 1 This is a structural diagram of the simulation device for transmitting laser signals under atmospheric turbulence provided in Embodiment 1 of the present invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0038] like Figure 1 As shown, this embodiment provides a simulation device for the transmission of laser signals under atmospheric turbulence, including an optical modulation module, an optical coupler, and an optical transmitting antenna connected in sequence via optical fibers; the optical modulation and transmitting module is electrically connected to the control module;

[0039] The signal source generates a frequency signal and sends it to the optical modulation module; the optical modulation module includes a laser, a modulation signal generation unit, and an optical modulation unit; the modulation signal generation unit is electrically connected to the control module;

[0040] The modulation signal generation unit uses the frequency signal output by the signal source to generate a burst modulation signal of a specific format; the optical modulation unit loads the burst modulation signal generated by the burst modulation signal generation unit onto the laser to generate a laser signal.

[0041] The optical modulation module modulates the frequency signal into a laser signal under the control of the control module, and then transmits it through the optical transmitting antenna. The laser signal is transmitted through the atmospheric turbulence channel and reaches the reflector. The reflector reflects the laser signal and then transmits it through the atmospheric turbulence channel to the optical receiving antenna. In order to control link loss and facilitate stable alignment, the distance between the optical transmitting antenna and the optical receiving antenna is greater than 100m, thereby disrupting the symmetry and reciprocity of the round-trip atmospheric link.

[0042] The optical receiving antenna is connected to the input terminal of the first optical switch via an optical fiber; the output terminal of the first optical switch is connected to the optical delay module and the optical receiving module via an optical fiber; the first optical switch is used to switch the optical path from the optical receiving antenna to the optical delay module and the optical receiving module; the optical delay module is simultaneously connected to an optical coupler via an optical fiber; the optical delay module is electrically connected to the control module.

[0043] The optical delay module includes a first optical amplifier, a second optical switch, a dispersion compensator, an optical signal controller, and an optical fiber of a set length. The first optical switch and the input of the first optical amplifier are connected via optical fiber. The first optical amplifier, the optical fiber of the set length, the dispersion compensator, and the second optical switch are sequentially connected via optical fiber. The output of the second optical switch is connected via optical fiber to an optical coupler and the input of the first optical amplifier. The second optical switch is used to switch the delayed loop optical path between the laser signal to the optical coupler and the laser signal to the input of the first optical amplifier.

[0044] The input terminal of the optical signal controller is electrically connected to the control module; the output terminal of the optical signal controller is electrically connected to the second optical switch and the dispersion compensator; the optical signal controller receives the control command output by the control module and adjusts the switching direction of the second optical switch according to the control command.

[0045] The laser signal is sent to the input of the first optical amplifier through the second optical switch. It is amplified, delayed and dispersion compensated in a repetitive cycle inside the optical delay module to increase the delay time of the laser signal.

[0046] The laser signal undergoes m round trips between the transmitting antenna, reflector, and receiving antenna to simulate the transmission characteristics of laser signals under long-distance turbulence, thereby achieving cyclic transmission of the laser signal in the atmospheric turbulence channel and extending the turbulence channel distance through equivalent superposition. During this process, the control module regulates the generation time and duration of the burst laser signal from the optical modulation module, as well as the delay amount of the optical delay unit and the switching timing of the optical switch.

[0047] Under the control of the control module, the first optical switch determines the number of times the laser signal is cyclically transmitted in the atmospheric turbulence channel. When the number of round-trip transmissions reaches m, the laser signal is transmitted to the optical receiving module. The optical receiving module includes a second optical amplifier, an optical demodulation and signal recovery unit connected in sequence through optical fibers. The second optical amplifier is connected to the optical switch through an optical fiber.

[0048] In this embodiment, a dispersion-compensated and amplified fiber delay loop is introduced into the turbulence test link, extending the atmospheric turbulence channel distance through equivalent superposition. This allows for a more realistic simulation of laser signal transmission characteristics under strongly and weakly correlated turbulence over long distances in an atmospheric laser link. When the optical signal delay time in the delay module is extremely short (e.g., below microseconds), the impact of strongly correlated long-distance turbulence on laser signal transmission can be simulated; when the optical signal delay time in the delay module is relatively long (e.g., on the order of milliseconds), the impact of weakly correlated long-distance turbulence on laser signal transmission can be simulated.

[0049] A control method for a simulation device of laser signal transmission under atmospheric turbulence, specifically including:

[0050] The control module controls the signal source to generate a frequency signal and send it to the optical modulation module; the control module controls the modulation signal generation unit to generate a burst modulation signal of a specific format using the frequency signal output by the signal source. ;in, This indicates the round-trip time delay of the laser signal in the atmosphere. This indicates the propagation delay of the laser signal in the optical fiber of the optical delay module;

[0051] The formula for calculating the round-trip propagation delay of a laser signal in the atmosphere is:

[0052] ;

[0053] In the formula, Indicates the number of loops. This represents the transmission distance from the optical transmitting antenna or optical receiving antenna to the reflector, where c is the speed of light.

[0054] The formula for calculating the propagation delay of a laser signal in the optical fiber of an optical delay module is as follows:

[0055] ;

[0056] In the formula, Indicates the fiber transmission distance in the fiber delay loop. The refractive index in the optical fiber;

[0057] The optical modulation unit loads the burst modulation signal generated by the burst modulation signal generation unit onto the laser to generate a laser signal.

[0058] The frequency signal is modulated into a laser signal and then emitted through the optical transmitting antenna. The laser signal is transmitted through an atmospheric turbulence channel to a reflector, which reflects the signal before transmitting it through another atmospheric turbulence channel to the optical receiving antenna. To control link loss and facilitate stable alignment, the distance between the antenna and the reflector is set to 500. The distance between the transmitting and receiving antennas should be greater than 100. By exceeding the turbulence scale shown by the undulating line in the figure, the symmetry and reciprocity of the back-and-forth atmospheric links are disrupted, thereby enabling the simulation of long-distance atmospheric turbulence transport.

[0059] When the optical receiving antenna receives the laser signal and sends it into the optical delay module, the laser signal is sent to the input terminal of the first optical amplifier through the second optical switch. It is amplified, delayed and dispersion compensated by repeating the loop inside the optical delay module. After the laser signal is repeated h times inside the optical delay module, it is sent to the optical transmitting antenna through the optical coupler.

[0060] The laser signal is transmitted m times between the optical transmitting antenna, the reflector, the optical receiving antenna, the first optical switch and the optical delay module to simulate the transmission characteristics of the laser signal under long-distance turbulence. When the number of round-trip transmissions reaches m, the laser signal is transmitted to the optical receiving module.

[0061] When the optical signal delay time in the delay module is extremely short (e.g., below microseconds), it can simulate the effect of laser signal transmission under strong correlation long-distance turbulence; when the optical signal delay time in the delay module is relatively long (e.g., on the order of milliseconds), it can simulate the effect of laser signal transmission under weak correlation long-distance turbulence.

[0062] In this implementation example, when the optical signal delay time in the delay loop module is extremely short (e.g., below microseconds), that is, within the delay loop, ,at this time, Representative 2 This can simulate the transmission characteristics of laser signals under strongly correlated long-distance turbulence. When the optical signal delay time in the optical delay loop module is long (e.g., on the order of milliseconds), that is, in the delay unit, when... , Representing 200 The simulation was repeated 20 times. The characteristics of laser signal transmission under weakly correlated long-distance turbulence were investigated.

[0063] This embodiment uses a short-distance atmospheric link to generate turbulence samples. The linear and stable storage and transmission of the fiber optic link, combined with high-precision delay control, works together to realistically simulate the influence of strongly correlated and weakly correlated turbulence on the laser signal in a long-distance atmospheric laser link.

[0064] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0065] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0066] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0067] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0068] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A device for simulating the transmission of laser signals under atmospheric turbulence, characterized in that, It includes a signal source, an optical modulation module, an optical coupler, and an optical transmitting antenna connected sequentially via optical fiber; the optical modulation and transmitting module is electrically connected to the control module; The signal source generates a frequency signal and sends it to the optical modulation module; the optical modulation module modulates the frequency signal into a laser signal under the action of the control module and then transmits it through the optical transmitting antenna. The laser signal is transmitted through the atmospheric turbulence channel and then reaches the reflector. The reflector reflects the laser signal and then transmits it through the atmospheric turbulence channel to the optical receiving antenna. The optical receiving antenna is connected to the input terminal of the first optical switch via an optical fiber; the output terminal of the first optical switch is connected to the optical delay module and the optical receiving module via an optical fiber; the first optical switch is used to switch the optical path from the optical receiving antenna to the optical delay module and the optical receiving module; the optical delay module is simultaneously connected to an optical coupler via an optical fiber; the optical delay module is electrically connected to the control module. After receiving the laser signal, the optical receiving antenna sends it to the optical delay module through the first optical switch. The optical delay module amplifies, delays, and compensates for dispersion of the laser signal before inputting it to the optical coupler. The laser signal is transmitted m times between the optical transmitting antenna, the reflector, the optical receiving antenna, the first optical switch, and the optical delay module to simulate the transmission characteristics of the laser signal under long-distance turbulence. When the number of round-trip transmissions reaches m, the laser signal is transmitted to the optical receiving module.

2. The simulation device for laser signal transmission under atmospheric turbulence according to claim 1, characterized in that, The optical modulation module includes a laser, a modulation signal generation unit, and an optical modulation unit; the modulation signal generation unit is electrically connected to the control module. The modulation signal generation unit uses the frequency signal output by the signal source to generate a burst modulation signal of a specific format; the optical modulation unit loads the burst modulation signal generated by the burst modulation signal generation unit onto the laser to generate a laser signal.

3. The simulation device for laser signal transmission under atmospheric turbulence according to claim 1, characterized in that, The optical delay module includes a first optical amplifier, a second optical switch, a dispersion compensator, an optical signal controller, and an optical fiber of a set length. The first optical switch and the input of the first optical amplifier are connected via optical fiber. The first optical amplifier, the optical fiber of the set length, the dispersion compensator, and the second optical switch are sequentially connected via optical fiber. The output of the second optical switch is connected via optical fiber to an optical coupler and the input of the first optical amplifier. The second optical switch is used to switch the delayed loop optical path between the laser signal to the optical coupler and the laser signal to the input of the first optical amplifier. The input terminal of the optical signal controller is electrically connected to the control module; the output terminal of the optical signal controller is electrically connected to the optical switch and the dispersion compensator; the optical signal controller receives the control commands output by the control module and adjusts the switching direction of the optical switch according to the control commands.

4. The simulation device for laser signal transmission under atmospheric turbulence according to claim 3, characterized in that, The laser signal is sent to the input of the first optical amplifier through the second optical switch. It is amplified, delayed and dispersion compensated in a repetitive cycle inside the optical delay module to increase the delay time of the laser signal.

5. The simulation device for laser signal transmission under atmospheric turbulence according to claim 3, characterized in that, The optical receiving module includes a second optical amplifier, an optical demodulation and signal recovery unit connected in sequence via optical fibers; the second optical amplifier is connected to the first optical switch via optical fibers.

6. The control method for the simulation device according to any one of claims 1 to 5, characterized in that, include: The signal source is controlled to generate a frequency signal and send it to the optical modulation module; The frequency signal is modulated into a laser signal and then emitted through the optical transmitting antenna; The laser signal is transmitted through the atmospheric turbulence channel and then reaches the reflector. The reflector reflects the laser signal and then transmits it through the atmospheric turbulence channel to the optical receiving antenna. When the optical receiving antenna receives the laser signal and sends it into the optical delay module, the laser signal is sent to the input terminal of the first optical amplifier through the second optical switch. It is amplified, delayed and dispersion compensated by repeating the loop inside the optical delay module. After the laser signal is repeated h times inside the optical delay module, it is sent to the optical transmitting antenna through the optical coupler. The laser signal is transmitted m times between the optical transmitting antenna, the reflector, the optical receiving antenna, the first optical switch, and the optical delay module to simulate the transmission characteristics of the laser signal under long-distance turbulence. When the number of round-trip transmissions reaches m, the laser signal is transmitted to the optical receiving module.

7. The control method according to claim 5, characterized in that, The optical modulation module includes a laser, a modulation signal generation unit, and an optical modulation unit; the control module controls the modulation signal generation unit to generate a burst modulation signal of a specific format using the frequency signal output from the signal source; ;in, This indicates the round-trip time delay of the laser signal in the atmosphere. This indicates the propagation delay of the laser signal in the optical fiber of the optical delay module; The optical modulation unit loads the burst modulation signal generated by the burst modulation signal generation unit onto the laser to generate a laser signal.

8. The control method according to claim 7, characterized in that, The formula for calculating the round-trip propagation delay of a laser signal in the atmosphere is: ； In the formula, Indicates the number of loops. This represents the transmission distance from the optical transmitting antenna or optical receiving antenna to the reflector, where c is the speed of light.

9. The control method according to claim 7, characterized in that, The formula for calculating the propagation delay of a laser signal in the optical fiber of an optical delay module is as follows: ； In the formula, Indicates the fiber transmission distance in the fiber delay loop. is the refractive index in the optical fiber.

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