A laser communication and laser imaging integrated system

Abstract

The application discloses a kind of laser communication and laser imaging integrated system, including transmitting end and receiving end;The transmitting end includes the communication signal modulation unit, pulse laser source and transmitting optical path connected in sequence;The receiving end includes receiving optical path, photoelectric detector, amplification circuit, signal acquisition unit, communication signal demodulation unit and image reconstruction unit;The laser communication and laser correlation imaging mode based on pulse position modulation are used in the application, laser communication and laser imaging system can be realized in sharing hardware resources, function is relatively independent, not dependent on each other, and system performance is not sacrificed.At the same time, two systems can work independently also can work simultaneously to realize the effect of "visual communication".

Description

Technical Field

[0001] This invention belongs to the field of space laser communication and laser imaging, and particularly relates to an integrated system for laser communication and laser imaging. Background Technology

[0002] Laser communication and laser imaging are important areas of information laser applications. Compared to traditional microwave communication, laser communication offers greater bandwidth and is more resistant to electromagnetic interference. Laser imaging also has unique advantages over traditional infrared imaging, overcoming environmental interference under certain conditions. In some military and civilian applications, both technologies and functions are often required simultaneously, necessitating the establishment of separate laser communication and laser imaging systems. Furthermore, to extend communication or imaging distances and achieve excellent system performance, laser communication or laser imaging systems typically require high-quality, high-power lasers and other optoelectronic devices. These optoelectronic devices, especially high-power lasers, are often expensive, have complex heat dissipation structures, and are large in size, consuming significant resources within the system. Therefore, constructing separate laser communication and laser imaging systems would require two sets of laser transmitting and receiving devices, placing high demands on the application platform and operating environment, and resulting in relatively high construction costs. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes an integrated laser communication and laser imaging system to resolve the issues present in the prior art.

[0004] To achieve the above objectives, the present invention provides an integrated laser communication and laser imaging system, including a transmitter and a receiver;

[0005] The transmitting end includes a communication signal modulation unit, a pulsed laser source, and an optical emission path connected in sequence.

[0006] The receiving end includes a receiving optical path, a photodetector, an amplifier circuit, a signal acquisition unit, a communication signal demodulation unit, and an image reconstruction unit;

[0007] The receiving optical path, photodetector, amplifier circuit, signal acquisition unit, and image reconstruction unit are connected in sequence;

[0008] The integrated system also includes an optical field modulator, which is disposed between the pulsed laser source and the transmitting optical path or between the receiving optical path and the photodetector;

[0009] The communication signal demodulation unit is connected to the amplification circuit, the image reconstruction unit is connected to the amplification circuit and the optical field modulator through control signals and modulation signals respectively, and the communication signal modulation unit is connected to the signal acquisition unit, the image reconstruction unit and the optical field modulator respectively.

[0010] Preferably, the wavelength of the communication receiving signal used at the receiving end is the same as the wavelength used for imaging by the pulse light source at the transmitting end.

[0011] Preferably, the communication signal modulation unit includes an external data interface circuit, a signal encoding and modulation unit, a signal synchronization and delay unit, and a level conversion circuit;

[0012] The external data interface circuit is used to input communication signals from external devices into the communication signal modulation unit;

[0013] The signal encoding and modulation unit is used to encode and map the input raw data signal to obtain the modulated communication signal;

[0014] The signal synchronization and delay unit is used to output a synchronization signal based on the modulated communication signal and to synchronize the laser imaging optical field modulator, the receiver signal acquisition unit and the image reconstruction unit.

[0015] The level conversion circuit is used to adjust the modulated and encoded electrical signal to a suitable level signal output for use by the pulsed laser source.

[0016] Preferably, the method for the signal encoding and modulation unit to perform modulation includes: framing and encoding the input communication signal, and then performing encoding mapping of pulse position modulation in the corresponding format;

[0017] The minimum symbol time interval in the modulated signal after passing through the signal encoding and modulation unit is greater than the timing interval corresponding to the maximum repetition frequency of the pulse emitted by the pulsed laser source.

[0018] Preferably, the method for synchronizing the signal synchronization and delay unit includes: when there is no external communication data input, the signal synchronization and delay unit provides an internal trigger timing signal to drive the pulsed laser source to emit light, and the synchronization signal serves as the internal trigger timing signal of the pulsed laser source, and this timing signal is synchronized to the optical field modulator, the signal acquisition unit of the receiver, and the image reconstruction unit; when there is external communication data input, the encoded communication modulation signal serves as the trigger signal of the pulsed laser source, and the signal synchronization and delay unit synchronizes the optical field modulator, the signal acquisition unit of the receiver, and the image reconstruction unit.

[0019] Preferably, the pulsed laser source has an external triggering mode, that is, the emission of laser pulses is triggered by an external data signal.

[0020] Preferably, the image reconstruction unit operates by:

[0021] The target image is reconstructed by performing correlation calculations based on the detected light intensity information and modulated light field distribution information;

[0022] Provide modulation signals for the optical field modulator;

[0023] It provides judgment input conditions for the output signal distribution of the amplification circuit after the photodetector. When the image reconstruction unit outputs the light field modulation signal to the light field modulator, the receiver enters the imaging mode. The amplification circuit distributes the detected signal to the signal acquisition unit of the laser imaging system; otherwise, it distributes it to the communication signal demodulation unit.

[0024] This invention also discloses a method for operating an integrated laser communication and laser imaging system, comprising:

[0025] When only imaging detection is required, the pulsed laser source emits uniform repetition rate pulsed laser in internal trigger mode without loading a communication signal. The receiving end performs correlation calculation on the pulsed light signal reflected back from the target to reconstruct the target image.

[0026] When only communication transmission and reception functions are required, the pulsed laser source adopts an external trigger mode. After the communication signal is loaded by the communication signal modulation unit, the pulsed signal light is emitted. At the same time, the image reconstruction unit is in standby mode, and the optical field modulator does not load the optical field modulation signal.

[0027] When communication and imaging are required simultaneously, the pulsed laser source adopts an external triggering mode. After the communication signal is loaded by the communication signal modulation unit, the pulsed signal light is emitted, and the optical field modulator loads the optical field modulation signal required for imaging.

[0028] Preferably, the signal modulation format and parameters received by the communication signal demodulation unit correspond to the signal modulation format and parameters of the communication signal modulation unit of the communication target transmitter, and are independent of the modulation format and parameters of the signal modulation unit of the local transmitter.

[0029] Compared with the prior art, the present invention has the following advantages and technical effects:

[0030] This invention provides an integrated laser communication and laser imaging system. Because it uses pulse position modulation to load the communication signal, it does not reduce the average optical pulse emission frequency of the pulsed laser. Therefore, compared to laser correlation imaging using a pulsed laser operating in a uniform repetition frequency mode, it does not sacrifice the overall frame rate of the imaging and improves the communication rate under the condition of limited maximum repetition rate of the pulsed laser. At the same time, since it does not change the average optical pulse frequency of the pulsed laser, it does not reduce the energy of the optical pulse and therefore does not sacrifice the effective range of laser correlation imaging.

[0031] The present invention provides an integrated laser communication and laser imaging system. Since the laser communication system and the laser imaging system share a laser source, driving circuit and transmitting optical path at the transmitting end, and share a receiving optical path and photodetector at the receiving end, it can greatly save the overall system size, hardware cost and power consumption compared with independent laser communication and laser imaging systems.

[0032] This invention provides an integrated laser communication and laser imaging system. Because the laser communication system uses pulse position modulation to load the communication signal, the signal encoding is characterized by the position of the light pulse within the pulse time slot. Conversely, the laser imaging system uses a correlated imaging method, where image reconstruction depends only on the energy of the received light pulse and the distribution of the modulated light field, and is independent of the time slot position of the light pulse. Therefore, the modulation signal dimensions of the laser communication system and the laser imaging system are different, making them relatively independent and preventing mutual interference. Thus, while sharing hardware resources, the laser communication system and the laser imaging system do not depend on or interfere with each other. The two systems can operate simultaneously or independently, offering highly flexible operation without affecting each other's performance.

[0033] This invention provides an integrated laser communication and laser imaging system. Because the laser communication system and the laser imaging system can work simultaneously, it can achieve a "visual communication" effect on the other end of the communication. In certain special application scenarios, it can serve as a visual monitoring, command, and control system.

[0034] The present invention provides an integrated laser communication and laser imaging system. Due to the maximized integration of the laser communication system and the laser imaging system, the hardware resource consumption is greatly reduced. At the same time, the use of a high-power pulsed laser source and pulse modulation method increases the detection and communication distance. Therefore, it is particularly suitable for application environments with long distance or high loss channel conditions such as underwater and deep space, as well as military and civilian application platforms that are sensitive to energy consumption and size. Attached Figure Description

[0035] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0036] Figure 1 This is a structural diagram of an integrated laser communication and laser imaging system according to an embodiment of the present invention. Detailed Implementation

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0039] Example 1

[0040] like Figure 1 As shown, this embodiment provides an integrated laser communication and laser imaging system, including a transmitter and a receiver;

[0041] The transmitting end includes a communication signal modulation unit, a pulsed laser source, and a transmitting optical path connected in sequence;

[0042] The communication signal modulation unit comprises an external data interface circuit, a signal encoding and modulation unit, a signal synchronization and delay unit, and a level conversion circuit. The external data interface circuit receives communication signals from external devices and inputs them into the communication signal modulation unit. The signal encoding and modulation unit encodes and maps the input raw data signal. The signal synchronization and delay unit outputs a synchronization signal based on the modulated communication signal, used for synchronization between the laser imaging optical field modulator and the receiving signal acquisition unit. The level conversion circuit adjusts the modulated and encoded electrical signal to a suitable output level for use by the pulsed laser source.

[0043] The signal encoding and modulation unit in the communication signal modulation unit performs pulse position modulation (PPM) on the externally input data signal. Specifically, the input signal data is first framed and encoded according to requirements, and then encoded and mapped to the corresponding PPM format, such as 8PPM, 16PPM, or other PPM signal modulation formats. Alternatively, other types of pulse signal modulation formats optimized from PPM, such as DPPM and MPPM, can also be used. Furthermore, limited by the maximum repetition frequency of the pulsed laser source, the minimum symbol time interval within the modulated signal after passing through the signal encoding and modulation unit is the timing interval corresponding to the maximum repetition frequency of the emitted light pulses from the pulsed laser source.

[0044] The signal synchronization and delay unit in the communication signal modulation unit is used to synchronize the communication signal with the imaging optical field modulator and the signal acquisition unit at the receiving end. According to the principle of laser-linked imaging, accurate acquisition of the returned optical pulse signal is required during image reconstruction, and the modulation signal of the optical field modulator also needs to be synchronized with the optical pulses emitted by the pulsed laser source. Therefore, a synchronization signal is a necessary condition for laser-linked imaging. This synchronization essentially uses the timing of the optical pulses emitted by the pulsed laser source as the synchronization trigger signal for the optical field modulator and the signal acquisition unit. However, in the integrated communication and imaging scheme, the timing of the optical pulses emitted by the pulsed laser source is determined by the pulse modulation signal after the input raw communication data has passed through the signal encoding and modulation unit. Therefore, this is equivalent to the modulated communication signal serving as the synchronization signal for the laser imaging unit. When there is no external communication data input, this synchronization signal is the internal trigger timing signal of the pulsed laser source. Furthermore, the synchronization signal of the signal acquisition unit can be set with an optimized time delay to match the transmission delay of the laser pulse in the imaging detection path; the delay time is determined by the imaging distance. Meanwhile, if the optical field modulator is placed at the receiving end, the modulated signal received by the optical field modulator should also be optimized with the same time delay to match the transmission delay of the laser pulse in the imaging detection path.

[0045] The level conversion circuit in the communication signal modulation unit is used to adjust the level of the pulse-modulated communication signal in order to match the external trigger level of the pulse laser source.

[0046] Pulsed laser sources are used to generate the pulsed laser light required for both communication and imaging. Specifically, pulsed laser sources can be various types of pulsed lasers, such as fiber lasers or solid-state lasers. Furthermore, to ensure the loading of communication signals modulated by the communication signal modulation unit, the pulsed laser source needs to have an external triggering mode, meaning that the emission of laser pulses is triggered by an external data signal.

[0047] An optical field modulator is used to modulate the optical field distribution of the pulsed signal light emitted by a pulsed laser source. Specifically, the optical field modulator can employ different types and materials of optical field intensity modulation devices or phase modulators, such as digital micromirror devices (DMDs) and phase plates, depending on the specific application and requirements. Furthermore, the optical field modulator can be placed after the pulsed laser source at the transmitting end to directly modulate the optical field of the emitted pulsed laser; alternatively, it can be placed before the photodetector at the receiving end. Additionally, the modulation signal source for the optical field modulator is provided by the image reconstruction unit at the receiving end, enabling the laser pulse to form a preset speckle field distribution. Simultaneously, the optical field modulator can also employ a frosted glass-type random modulation device to form a random speckle field distribution, in which case it needs to be detected by a CCD and fed back to the image reconstruction unit.

[0048] The transmitting optical path at the transmitting end completes the target alignment, and the aligned target is both the imaging target and the communication target.

[0049] The transmitting optical path simultaneously performs beam adjustment, shaping the pulsed signal light emitted by the pulsed laser source into spatial signal light that meets beam quality requirements. The spot shape and divergence angle of the emitted beam are designed based on the characteristics of the imaging target.

[0050] The transmitting optical path can use functional devices such as optical switches to achieve multi-optical path selection and control. In addition, with the help of tunable optical collimators, several typical beam states can be preset, and then the spot shape and emission angle of the emitted beam can be quickly switched and controlled according to the requirements of imaging and communication targets.

[0051] The optical pulse signal passing through the optical field modulator at the transmitting end simultaneously carries the communication signal and the optical field modulation information required for imaging, and is aligned with the imaging and communication targets via the transmitting optical path. That is, the laser imaging system and the laser communication system share the pulsed laser source and the transmitting optical path.

[0052] The receiving end includes a receiving optical path, a photodetector, an amplifier circuit, a signal acquisition unit, a communication signal demodulation unit, and an image reconstruction unit. The laser imaging system and the laser communication system at the receiving end can share the receiving optical path and the photodetector. The wavelength of the communication receiving signal used at the receiving end is the same as the wavelength used for imaging with the pulsed light source at the transmitting end.

[0053] The receiving optical path, photodetector, amplifier circuit, signal acquisition unit, and image reconstruction unit are connected in sequence;

[0054] The receiving end can receive non-pulse continuous optical modulation signals or other modulation formats of optical signals, depending on the signal emitted by the target transmitter. It is relatively independent of the modulation format and parameters of the pulsed optical signal emitted by the local transmitter.

[0055] When the receiver receives a communication signal, the optical field modulator is in a transmission state and no modulation signal is loaded.

[0056] The integrated system also includes an optical field modulator, which is positioned between the pulsed laser source and the transmitting optical path or between the receiving optical path and the photodetector;

[0057] The communication signal demodulation unit is connected to the amplifier circuit, the image reconstruction unit is connected to the amplifier circuit and the optical field modulator through the control signal and the modulation signal, respectively, and the communication signal modulation unit is connected to the signal acquisition unit, the image reconstruction unit and the optical field modulator, respectively.

[0058] The receiver can be an integrated design of laser communication and laser imaging, or it can be independent of the communication signal demodulation unit. In this case, the receiver becomes an independent receiver of the laser-correlated imaging system.

[0059] The receiving optical path at the receiving end is a shared receiving optical path for both the laser communication and laser imaging systems. It is used to receive the pulsed light field reflected back from the imaging target by the laser imaging system, or the pulsed signal light emitted by the laser communication system at the other end.

[0060] The aforementioned photodetector is used as a shared photodetector for both laser imaging and laser communication systems, converting the pulsed light field reflected from the laser imaging target or the pulsed light signal transmitted from the counterpart laser communication system into an electrical signal. Furthermore, the type of photodetector can be selected based on the application requirements and the parameters of the transmitting pulsed laser source.

[0061] The aforementioned amplifier circuit is used to linearly amplify the signal detected by the photodetector. Furthermore, the amplifier circuit splits the amplified electrical signal into two paths: one path connects to the communication signal demodulation unit of the laser communication system, and the other path connects to the signal acquisition unit of the laser imaging system.

[0062] The signal acquisition unit is used to acquire data after the laser imaging light pulse signal is detected, and then hands the acquired data over to the image reconstruction unit for final image reconstruction. Specifically, the signal acquisition unit can be a dedicated signal acquisition card or sampling chip, the sampling frequency is determined by the light pulse width, and the data storage depth is determined by the data processing requirements of the image reconstruction unit.

[0063] The image reconstruction unit, used for image reconstruction in laser correlation imaging, is the core unit of laser imaging. Specifically, the image reconstruction unit reconstructs the target image by performing correlation calculations based on the detected light intensity information and the modulated light field distribution information. Simultaneously, the image reconstruction unit also needs to provide a modulation signal to the light field modulator. Furthermore, while providing the light field modulation signal, the image reconstruction unit also provides a judgment input condition for the output signal allocation of the amplification circuit after the photodetector. When the image reconstruction unit outputs the light field modulation signal to the light field modulator, the receiver enters imaging mode, and the amplification circuit distributes the detected signal to the signal acquisition unit of the laser imaging system; otherwise, it distributes it to the communication signal demodulation unit.

[0064] The communication signal demodulation unit is used to demodulate and recover the received communication signal. Specifically, the design of the communication signal demodulation unit corresponds to the signal modulation format and parameters of the communication signal modulation unit at the transmitting end.

[0065] The aforementioned integrated laser communication and laser imaging system can flexibly implement multiple working modes and states according to actual application conditions, as detailed below:

[0066] (1) When only imaging detection function is needed, the pulsed laser source emits uniform repetition frequency pulsed laser in internal trigger mode without loading communication signal. The receiver performs correlation calculation on the pulsed light signal reflected back by the target to reconstruct the target image.

[0067] (2) When only communication transmission and reception functions are required, the pulsed laser source adopts the external trigger mode. The communication signal is loaded by the communication signal modulation unit and then the pulsed signal light is emitted. At the same time, the image reconstruction unit is in standby mode and the optical field modulator does not load the optical field modulation signal. At this time, the full-duplex communication requirements can be met.

[0068] (3) When both communication and imaging functions are required at the same time, the laser imaging system and the laser communication system transmitters operate normally and independently. The pulsed laser source adopts an external trigger mode. After the communication signal is loaded by the communication signal modulation unit, the pulsed signal light is emitted. The optical field modulator loads the optical field modulation signal required for imaging. At this time, imaging and communication of the target unit can be realized simultaneously, i.e., the "visualized" communication effect.

[0069] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An integrated laser communication and laser imaging system, characterized in that, Includes the transmitter and receiver; The transmitting end includes a communication signal modulation unit, a pulsed laser source, and an optical emission path connected in sequence. The receiving end includes a receiving optical path, a photodetector, an amplifier circuit, a signal acquisition unit, a communication signal demodulation unit, and an image reconstruction unit; The receiving optical path, photodetector, amplifier circuit, signal acquisition unit, and image reconstruction unit are connected in sequence; The wavelength of the communication signal used at the receiving end is the same as the wavelength used for imaging by the pulsed light source at the transmitting end; The optical pulse signal passing through the optical field modulator at the transmitting end simultaneously carries the communication signal and the optical field modulation information required for imaging, and is aligned with the imaging and communication target through the transmitting optical path; The integrated system also includes an optical field modulator, which is disposed between the pulsed laser source and the transmitting optical path or between the receiving optical path and the photodetector; The communication signal demodulation unit is connected to the amplification circuit, the image reconstruction unit is connected to the amplification circuit and the light field modulator through control signals and modulation signals respectively, and the communication signal modulation unit is connected to the signal acquisition unit, the image reconstruction unit and the light field modulator respectively. The communication signal modulation unit includes an external data interface circuit, a signal encoding modulation unit, a signal synchronization and delay unit, and a level conversion circuit. The external data interface circuit is used to input communication signals from external devices into the communication signal modulation unit; The signal encoding and modulation unit is used to encode and map the input raw data signal to obtain the modulated communication signal; The signal synchronization and delay unit is used to output a synchronization signal based on the modulated communication signal and to synchronize the laser imaging optical field modulator, the receiver signal acquisition unit and the image reconstruction unit. The level conversion circuit is used to adjust the modulated and encoded electrical signal into a suitable level signal for output to the pulsed laser source; The method for the signal encoding and modulation unit to perform modulation includes: framing and encoding the input communication signal, and then performing encoding mapping of pulse position modulation in the corresponding format; Laser communication systems use pulse position modulation to load communication signals, and the signal encoding of communication is characterized by the position of the light pulse in the pulse time slot; while laser imaging systems use correlation imaging, and image reconstruction is only related to the energy of the received light pulse and the distribution of the modulated light field, and is independent of the time slot position of the light pulse. Therefore, the modulation signal dimensions of laser communication systems and laser imaging systems are different, and they are relatively independent and will not affect each other. The minimum symbol time interval in the modulated signal after passing through the signal coding and modulation unit is greater than the timing interval corresponding to the maximum repetition frequency of the pulse emitted by the pulsed laser source. The method for synchronizing the signal synchronization and delay unit includes: when there is no external communication data input, the signal synchronization and delay unit provides an internal trigger timing signal to drive the pulsed laser source to emit light, and the synchronization signal serves as the internal trigger timing signal of the pulsed laser source, and this timing signal is synchronized to the optical field modulator, the signal acquisition unit of the receiver, and the image reconstruction unit; when there is external communication data input, the encoded communication modulation signal serves as the trigger signal of the pulsed laser source, and the signal synchronization and delay unit synchronizes the optical field modulator, the signal acquisition unit of the receiver, and the image reconstruction unit.

2. The integrated laser communication and laser imaging system according to claim 1, characterized in that, The pulsed laser source has an external triggering mode, meaning that the emission of laser pulses is triggered by an external data signal.

3. The integrated laser communication and laser imaging system according to claim 1, characterized in that, The image reconstruction unit operates as follows: The target image is reconstructed by performing correlation calculations based on the detected light intensity information and modulated light field distribution information; Provide modulation signals for the optical field modulator; It provides judgment input conditions for the output signal distribution of the amplification circuit after the photodetector. When the image reconstruction unit outputs the light field modulation signal to the light field modulator, the receiver enters the imaging mode. The amplification circuit distributes the detected signal to the signal acquisition unit of the laser imaging system; otherwise, it distributes it to the communication signal demodulation unit.

4. A method for operating an integrated laser communication and laser imaging system, characterized in that, For implementing the system according to any one of claims 1-3, comprising: When only imaging detection is required, the pulsed laser source emits uniform repetition rate pulsed laser in internal trigger mode without loading a communication signal. The receiving end performs correlation calculation on the pulsed light signal reflected back from the target to reconstruct the target image. When only communication transmission and reception functions are required, the pulsed laser source adopts an external trigger mode. After the communication signal is loaded by the communication signal modulation unit, the pulsed signal light is emitted. At the same time, the image reconstruction unit is in standby mode, and the optical field modulator does not load the optical field modulation signal. When communication and imaging are required simultaneously, the pulsed laser source adopts an external triggering mode. After the communication signal is loaded by the communication signal modulation unit, the pulsed signal light is emitted, and the optical field modulator loads the optical field modulation signal required for imaging.

5. The operating method of the integrated laser communication and laser imaging system according to claim 4, characterized in that, The signal modulation format and parameters received by the communication signal demodulation unit correspond to the signal modulation format and parameters of the communication signal modulation unit of the communication target transmitter, and are independent of the modulation format and parameters of the signal modulation unit of the local transmitter.

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