Communication device and system
Patent Information
- Application Number
- CN202510339804.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2026-09-22
Smart Images
Figure CN122802058A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of communication technology, and in particular to a communication device and system. Background Technology
[0002] With the development of communication technology, free space optical communication (FSO) is being used more and more. Free space optical communication is a communication technology that uses laser as a carrier and free space (such as the atmosphere) as the transmission medium. Free space can be simply referred to as space.
[0003] When free-space optical communication is performed between communication devices, one communication device transmits an optical signal carrying the data into space according to the electrical signal to be transmitted (carrying data); the other communication device receives the optical signal from the space and detects the optical signal to obtain the aforementioned electrical signal.
[0004] However, when optical signals are transmitted in space, they are easily affected by atmospheric turbulence and fluctuate, which affects the detection of optical signals by communication equipment and thus affects the stability of communication. Summary of the Invention
[0005] This application provides a communication device and system that can solve the problem of communication stability being affected by atmospheric turbulence. The solution provided in this application is as follows.
[0006] In a first aspect, a communication device is provided, comprising an optical antenna, an adjustment unit, and a detection unit; the optical antenna is used to receive a first optical signal transmitted in space and transmit the first optical signal to the adjustment unit; the adjustment unit is used to adjust the power and spatial distribution of the first optical signal before transmitting it to the detection unit; the detection unit is used to detect the first optical signal after the power and spatial distribution adjustments.
[0007] In the communication device provided in this application, the adjustment unit can adjust the power and spatial distribution of the first optical signal received by the optical antenna from space, and then transmit the first optical signal with adjusted power and spatial distribution to the detection unit for detection. In this way, based on the adjustment unit's functions of adjusting the power and spatial distribution of the first optical signal, the fluctuation of the first optical signal can be reduced and the stability of communication can be improved.
[0008] Furthermore, the aforementioned detection unit is capable of detecting optical signals within the target power range, and the aforementioned power adjustment can be used to adjust the power of the first optical signal to within the target power range. In this way, the power of the first optical signal can be kept within the detection range of the detection unit through the aforementioned power adjustment, reducing power jitter of the first optical signal in the time domain, thereby reducing the likelihood that the detection unit will be unable to detect the first optical signal.
[0009] Optionally, the aforementioned power adjustment is used to suppress power fluctuations in the first optical signal caused by atmospheric turbulence, ensuring that the power of the first optical signal remains within the dynamic range of power detectable by the detection unit. The aforementioned spatial distribution adjustment is used to suppress spatial distribution fluctuations in the first optical signal caused by atmospheric turbulence, thereby suppressing the mismatch between the spot size of the first optical signal and the target surface (also known as the photosensitive surface) of the detection unit caused by atmospheric turbulence. It is evident that through power adjustment and spatial distribution adjustment, the power and spot size of the first optical signal transmitted to the detection unit can be stabilized, thereby reducing fluctuations in the first optical signal caused by atmospheric turbulence and improving communication stability and reliability.
[0010] Optionally, the aforementioned spatial distribution adjustment is used to improve the uniformity and stability of the spatial distribution of the first optical signal. This spatial distribution adjustment can transform the first optical signal from a dynamically changing spot in shape and position into a stable, uniform spot, thereby reducing spatial distribution jitter in the first optical signal. With this stable spot, subsequent detection units can be designed based on it, allowing the stable spot to continuously transmit to the target surface of the detection unit, enabling the detection unit to continuously detect the first optical signal.
[0011] The first optical signal can undergo power adjustment and spatial distribution adjustment in sequence, or the first optical signal can undergo spatial distribution adjustment and power adjustment in sequence.
[0012] The adjustment unit may include one or more components. When the adjustment unit includes one component, that component is used to perform the power adjustment and spatial distribution adjustment; when the adjustment unit includes multiple components, the multiple components can cooperate to perform the power adjustment and spatial distribution adjustment. For example, the multiple components include: a power adjustment component and a spatial distribution adjustment component; the power adjustment component is used to adjust the power of the first optical signal; the spatial distribution adjustment component is used to adjust the spatial distribution of the first optical signal.
[0013] The aforementioned power adjustment component includes at least one of a variable optical attenuator (VOA) and an optical amplifier. For example, the power adjustment component includes a VOA, or it includes an optical amplifier, or it includes both a VOA and an optical amplifier. The VOA is capable of adjusting the upper limit of the power of the first optical signal so that the upper limit of the power of the first optical signal is within a target power range; the optical amplifier is capable of adjusting the lower limit of the power of the first optical signal so that the lower limit of the power of the first optical signal is within the target power range.
[0014] Optionally, the spatial distribution adjustment component includes a homogenizer, which may include at least one of a homogenizing fiber and a spatial optical field homogenizer. When the spatial distribution adjustment component is a spatial optical field homogenizer, there is no need to use optical fiber connections between the spatial distribution adjustment component and other components in the communication equipment (such as a detection unit or a power adjustment component).
[0015] Optionally, the adjustment unit further includes a multimode optical fiber, and the power adjustment component is disposed on the multimode optical fiber; the multimode optical fiber is used to transmit a first optical signal; the power adjustment component is used to adjust the power of the first optical signal transmitted in the multimode optical fiber.
[0016] Since the optical signal received from space by the optical antenna is a multimode optical signal, the first optical signal is also a multimode optical signal. Using this multimode optical fiber to transmit the first optical signal results in high coupling efficiency. Multimode optical fiber can efficiently transmit the first optical signal, which exhibits characteristics such as fragmentation, jitter, broadening, and angular-of-arrival fluctuations after atmospheric interference. Furthermore, when the homogenizing fiber is also multimode homogenized fiber, the coupling efficiency of the first optical signal within the multimode homogenized fiber is also high.
[0017] Furthermore, when the adjustment unit includes a multimode fiber, the first optical signal, when transmitted through the multimode fiber, will excite higher-order modes of different orders. These excited modes correspond to different spot sizes and divergence angles. If the first optical signal passes through the power adjustment component and the spatial distribution adjustment component sequentially, then during the transmission of the first optical signal from the multimode fiber, the first optical signal undergoes power adjustment. After being output from the multimode fiber, the first optical signal can also undergo spatial distribution adjustment in the spatial distribution adjustment component to stabilize the spot size and divergence angle of each mode of the first optical signal. If the first optical signal passes through the spatial distribution adjustment component and the power adjustment component sequentially, then after the first optical signal undergoes spatial distribution adjustment, the spot size and divergence angle of each mode of the first optical signal are stable. Even if it subsequently passes through the multimode fiber, it will stably excite higher-order modes of fixed orders, thus ensuring that the spot size and divergence angle of the first optical signal output from the multimode fiber are also stable.
[0018] The communication device provided in this application may further include a coupling unit for coupling a first optical signal output by the adjustment unit to the detection unit. For example, the coupling unit includes a focusing lens group located in the optical path between the adjustment unit and the detection unit.
[0019] By focusing the light through the focusing lens group, the spot size of the first optical signal after power and spatial distribution adjustments is reduced, allowing the communication equipment to use a detection unit with a smaller target surface. Generally, the higher the rate of the first optical signal, the smaller the target surface of the detection unit 033 used in the communication equipment. Focusing through the focusing lens group enables the communication equipment to be suitable for receiving first optical signals with higher rates. Furthermore, when the communication equipment includes multimode fiber, the spot size of the optical signal output from the multimode fiber is relatively large. Focusing through the focusing lens group reduces the spot size of the first optical signal, allowing it to hit the target surface of the detection unit and be effectively transmitted to the detection unit.
[0020] Optionally, the focusing lens group includes multiple levels of focusing lenses arranged at intervals along the optical path from the adjustment unit to the detection unit, with the first-level focusing lens closest to the detection unit being attached to the detection unit. When the first-level focusing lens closest to the detection unit is attached to the detection unit, the divergence angle of the first optical signal transmitted from the focusing lens group to the detection unit is smaller, thereby supporting a smaller detection surface of the detection unit and making the communication device suitable for receiving first optical signals with higher reception rates.
[0021] The refractive index of the first-stage focusing lens closest to the detection unit in the above-mentioned multi-stage focusing lens can be greater than 1.7. It can be seen that the first-stage focusing lens closest to the detection unit in the multi-stage focusing lens 0341 has a high refractive index. In this way, the divergence angle of the first optical signal transmitted from the focusing lens group 034 to the detection unit is also smaller, and it can also support the detection surface of the detection unit to be smaller, so that the communication equipment is suitable for receiving first optical signals with a high receiving rate.
[0022] In the above description, the first optical signal may have one wavelength; it is understood that the first optical signal may also have multiple wavelengths. The detection unit includes multiple detectors, and the first optical signal has multiple wavelengths corresponding one-to-one with each of the multiple detectors. The communication device also includes a first beam splitting unit, which is located on the optical path between the adjustment unit and the detection unit. The first beam splitting unit is used to receive the first optical signal after power adjustment and spatial distribution adjustment, and to transmit the components of multiple wavelengths in the first optical signal after power adjustment and spatial distribution adjustment to their respective detectors. The detectors are used to detect the components of the corresponding wavelengths after power adjustment and spatial distribution adjustment.
[0023] Optionally, multiple detector arrays are arranged; the communication device includes: a multi-stage focusing lens arranged at intervals in the optical path between the adjustment unit and the detection unit, wherein the first-stage focusing lens closest to the detection unit in the multi-stage focusing lens includes multiple focusing lenses; the multiple focusing lenses correspond one-to-one with multiple detectors, and any one of the multiple focusing lenses is located in the optical path between the adjustment unit and the corresponding detector.
[0024] The above description uses a communication device for receiving a first optical signal as an example. Optionally, the communication device may also have the function of transmitting a second optical signal. For example, the communication device further includes: a second beam splitting unit and a transmitting unit; an optical antenna for transmitting the first optical signal to an adjustment unit via the second beam splitting unit; a transmitting unit for transmitting a second optical signal to the second beam splitting unit, the wavelength of which is different from the wavelength of the first optical signal; the second beam splitting unit for transmitting the second optical signal to the optical antenna; and the optical antenna for transmitting the second optical signal into space.
[0025] In the aforementioned communication devices, the adjustment unit is used to adjust the power and spatial distribution of the first optical signal before transmitting it to the detection unit. Optionally, in the aforementioned communication devices, the adjustment unit may also adjust the power or spatial distribution of the first optical signal before transmitting it to the detection unit; this application does not limit this. For example, this application provides a communication device comprising: an optical antenna, a power adjustment component, a multimode optical fiber, and a detection unit; the optical antenna is used to receive a first optical signal transmitted in space and transmit the first optical signal to the multimode optical fiber; the power adjustment component is used to adjust the power of the first optical signal transmitted in the multimode optical fiber; and the detection unit is used to detect the power-adjusted first optical signal output from the multimode optical fiber.
[0026] In a second aspect, this application provides a communication system comprising: a first device and a second device; the first device is used to transmit a first optical signal into space; the second device is used to receive the first optical signal from space, and the second device includes any of the communication devices described in the first aspect. Attached Figure Description
[0027] Figure 1 A schematic diagram of a communication system provided in an embodiment of this application;
[0028] Figure 2 A schematic diagram of an adaptive optics technology provided in an embodiment of this application;
[0029] Figure 3 A schematic diagram of a communication device provided in an embodiment of this application;
[0030] Figure 4 A schematic diagram of another communication device provided in an embodiment of this application;
[0031] Figure 5 A schematic diagram of another communication device provided in an embodiment of this application;
[0032] Figure 6 A schematic diagram of another communication device provided in an embodiment of this application;
[0033] Figure 7 A schematic diagram of another communication device provided in an embodiment of this application;
[0034] Figure 8 A schematic diagram of another communication device provided in an embodiment of this application;
[0035] Figure 9 This is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation
[0036] This application provides a communication system comprising multiple devices capable of communicating with each other via optical signals transmitted in space (such as the atmosphere). This communication method is called Free-Speed (FSO) communication, where the space can be referred to as free space. Compared to microwave communication, FSO communication offers a series of advantages, including large bandwidth, free spectrum, small antenna size, and simple capacity evolution, and has enormous application potential in next-generation wireless communication.
[0037] The following explanation uses the first and second devices in a set of multiple devices as examples to illustrate the communication process between them. The communication process between any two devices in the set of multiple devices can be referenced from the communication process between the first and second devices.
[0038] The first device and the second device can both be ground-based devices (referred to as ground devices), or both can be air-based devices (referred to as air devices), or one of the first device and the other can be a ground device and the other an air device. Ground devices can be satellite ground stations, wireless base stations, etc.; air devices can be satellites, aircraft, hot air balloons, drones, etc.
[0039] For example, Figure 1 This is a schematic diagram of the structure of a communication system provided in an embodiment of this application, such as... Figure 1 As shown, the communication system includes a first device 01 and a second device 02. The distance between the first device 01 and the second device 02 is relatively large, for example, the distance between the first device 01 and the second device 02 is 1 kilometer to 20 kilometers.
[0040] The first device 01 includes a transmitting unit 011 and a first optical antenna 012, which can be connected via optical fiber. The transmitting unit 011 can transmit a first optical signal (laser) to the first optical antenna 012 via optical fiber according to the electrical signal (carrying data) to be transmitted. The first optical antenna 012 can transmit the first optical signal into space so that the first optical signal can be transmitted in a free space channel.
[0041] The second device 02 includes a detection unit 021 and a second optical antenna 022, which can be connected by an optical fiber. The second optical antenna 022 can receive the first optical signal transmitted in space and transmit the received first optical signal to the detection unit 021. Then, the detection unit 021 detects the first optical signal to obtain the electrical signal.
[0042] Taking the example of the first device 01 sending an optical signal to the second device 02, it can be understood that the second device 02 can also send an optical signal to the first device 01. In this case, the second device 02 may also include a transmitting unit, and the first device 01 may also include a detecting unit. The embodiments of this application will not be described in detail here.
[0043] The first optical signal transmitted into space by the first device 01 is typically a single-mode optical signal. During its transmission in free space, this single-mode signal fluctuates due to unstable factors (such as atmospheric turbulence), causing dynamic changes in the light spot, such as fragmentation, flickering, broadening, and angular arrival fluctuations. In other words, the single-mode optical signal transforms into a fluctuating multimode optical signal. However, the optical fiber between the second optical antenna 022 and the detection unit 021 in the second device 02 is typically a single-mode fiber. This single-mode fiber has low coupling efficiency for multimode optical signals. The loss fluctuation of the received optical signal in single-mode fiber is high, reaching over 30 dB, significantly affecting the stability of communication.
[0044] In related technologies, to improve communication stability, the second device 02 uses an adaptive optics system to adjust the optical signal affected by atmospheric turbulence before coupling it into a single-mode optical fiber. For example, the adaptive optics system is as follows: Figure 2 As shown, the second optical antenna of the second device 02 ( Figure 2(Not shown in the image) After receiving the first optical signal, the system transmits it to the wavefront corrector to adjust its wavefront. The adjusted wavefront is then transmitted to the wavefront detector, which detects the signal and transmits the result to the controller. If the detection result does not meet the requirements, the controller adjusts the wavefront corrector's parameters to improve its wavefront adjustment. This process is repeated until the controller determines that the detection result meets the requirements. However, the wavefront corrector and wavefront sensor are active devices, resulting in higher costs. Furthermore, there is a time delay between detection by the wavefront detector and the wavefront corrector's response. In highly turbulent environments, the wavefront of the first optical signal changes rapidly. Therefore, the time delay of the adaptive optics system makes it difficult to adapt to changes in the first optical signal in highly turbulent conditions, causing the wavefront corrector to be unable to effectively adjust the wavefront of the first optical signal.
[0045] In addition, in related technologies, to improve the coupling efficiency of multimode optical signals, the aforementioned single-mode fiber can be replaced with a multimode fiber that has a higher coupling efficiency for multimode optical signals. However, in these technologies, the communication equipment directly couples the signal light received through the multimode fiber to the detector's target surface. The optical signal received by the detector's target surface is dynamically changing in both time domain (power) and spatial distribution, affecting the detector's stable and efficient reception, and thus impacting the stability of communication.
[0046] Based on this, embodiments of this application provide a communication device and a communication system including the communication device. The communication device can process the received optical signal before detection. This processing can suppress optical signal fluctuations caused by atmospheric turbulence, thereby improving communication stability. Furthermore, the communication device can also use multimode fiber, which can improve the coupling efficiency of the optical signal. Moreover, the communication device can use low-cost devices to suppress jitter in the optical signal. Furthermore, the communication device does not employ… Figure 2 The feedback adjustment method shown modulates the optical signal, thus enabling the communication device to adjust the optical signal in strong turbulence scenarios.
[0047] For example, Figure 3 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application, such as... Figure 3 As shown, the communication device includes: an optical antenna 031, an adjustment unit 032, and a detection unit 033.
[0048] Optical antenna 031 is used to receive a first optical signal transmitted in space (free space) and transmit the first optical signal to adjustment unit 032. Optical antenna 031 can be implemented using a beamformer or other devices capable of receiving spatial light. After receiving the first optical signal, optical antenna 031 can directly transmit the first optical signal to adjustment unit 032, or it can transmit the first optical signal to adjustment unit 032 through at least one other component. For example, optical antenna 031 can transmit the first optical signal through a collimator (collimating lens). Figure 3 (Not shown in the image) is then transmitted to the adjustment unit 032 so that the first optical signal is collimated before entering the adjustment unit 032.
[0049] The adjustment unit 032 performs power adjustment and spatial distribution adjustment on the first optical signal before transmitting it to the detection unit 033. The adjustment unit 032 may include one or more components. When the adjustment unit 032 includes one component, that component performs the power adjustment and spatial distribution adjustment; when the adjustment unit 032 includes multiple components, the multiple components can cooperate to perform the power adjustment and spatial distribution adjustment.
[0050] For example, such as Figure 3 As shown, the plurality of components includes: a power adjustment component 0321 and a spatial distribution adjustment component 0322; the power adjustment component 0321 is used to adjust the power of the first optical signal; the spatial distribution adjustment component 0322 is used to adjust the spatial distribution of the first optical signal. Figure 3 In this configuration, the first optical signal can sequentially pass through the power adjustment component 0321 and the spatial distribution adjustment component 0322. In this case, the first optical signal undergoes power adjustment first, followed by spatial distribution adjustment. Alternatively, the first optical signal can sequentially pass through the spatial distribution adjustment component 0322 and the power adjustment component 0321. In this case, the first optical signal undergoes spatial distribution adjustment first, followed by power adjustment. Therefore, the first optical signal can undergo power adjustment and spatial distribution adjustment sequentially, or vice versa.
[0051] The detection unit 033 is used to detect the first optical signal after power adjustment and spatial distribution adjustment. After being transmitted to the detection unit 033, the first optical signal after power adjustment and spatial distribution adjustment is detected in the detection unit 033 to convert it into an electrical signal. The detection unit 033 can detect the received first optical signal using a direct detection method.
[0052] Optionally, the aforementioned spatial distribution adjustment is used to improve the uniformity and stability of the spatial distribution of the first optical signal. This spatial distribution adjustment can transform the first optical signal from a dynamically changing spot in shape and position into a stable, uniform spot, thereby reducing spatial distribution jitter in the first optical signal. With this stable spot, a subsequent detection unit 033 can be designed based on it, allowing the stable spot to continuously transmit to the target surface of the detection unit 033, enabling the detection unit 033 to continuously detect the first optical signal.
[0053] For example, when the first optical signal is affected by strong turbulence, the spot size of the first optical signal is large, and the uniformity of the brightness distribution of the spot is poor. When the first optical signal is affected by weak turbulence, the spot size of the first optical signal is small. After the above spatial distribution adjustment, regardless of whether it is affected by strong or weak turbulence, the spot size of the first optical signal can be stabilized within a certain range, and the uniformity of the brightness distribution of the spot is good.
[0054] For example, when the size of the first optical signal spot is larger than the size of the target surface of the detection unit 033, the aforementioned spatial distribution adjustment is used to reduce the size of the first optical signal spot; when the size of the first optical signal spot is smaller than the size of the target surface of the detection unit 033, the aforementioned spatial distribution adjustment is used to increase the size of the first optical signal spot. When the shape of the first optical signal spot is different from the shape of the target surface of the detection unit 033, the aforementioned spatial distribution adjustment is used to change the shape of the first optical signal spot to the shape of the target surface. When the uniformity of the first optical signal spot is outside the uniformity range, the aforementioned spatial distribution adjustment is used to improve the uniformity of the first optical signal spot so that the uniformity of the spot is within the uniformity range.
[0055] Of course, the above spatial distribution adjustment may not be used to improve at least one of the uniformity and stability of the spatial distribution of the first optical signal. For example, although the spatial distribution of the first optical signal is adjusted, the uniformity and stability of the spatial distribution of the first optical signal remain unchanged before and after the spatial distribution adjustment.
[0056] Optionally, the detection unit 033 can detect optical signals within the target power range, and the power adjustment can be used to adjust the power of the first optical signal to the target power range. In this way, the power of the first optical signal can be kept within the detection range of the detection unit 033 through the power adjustment, reducing the power jitter of the first optical signal in the time domain, thereby reducing the possibility that the detection unit 033 may be unable to detect the first optical signal.
[0057] For example, when the power of the first optical signal increases and exceeds the upper limit of the target power range, the adjustment unit 032 can reduce the power of the first optical signal to bring the power of the first optical signal within the target power range. When the power of the first optical signal decreases and is less than the lower limit of the target power range, the adjustment unit 032 can increase the power of the first optical signal to bring the power of the first optical signal within the target power range.
[0058] Of course, the power adjustment described above can also be used to adjust the power of the first optical signal to a power range that is different from the target power range, and this other power range may have a small deviation from the target power range.
[0059] Optionally, the aforementioned power adjustment is used to suppress power fluctuations in the first optical signal caused by atmospheric turbulence, ensuring that the power of the first optical signal remains within the dynamic range of power detectable by the detection unit. The aforementioned spatial distribution adjustment is used to suppress spatial distribution fluctuations in the first optical signal caused by atmospheric turbulence, thereby suppressing the mismatch between the spot size of the first optical signal and the target surface (also known as the photosensitive surface) of the detection unit caused by atmospheric turbulence. It is evident that through power adjustment and spatial distribution adjustment, the power and spot size of the first optical signal transmitted to the detection unit can be stabilized, thereby reducing fluctuations in the first optical signal caused by atmospheric turbulence and improving communication stability and reliability, compared to traditional few-mode reception methods (such as...). Figure 1 As shown in the figure, the overall reception efficiency is improved by more than 20dB.
[0060] The power adjustment described above may not be used to suppress power fluctuations in the first optical signal caused by atmospheric turbulence, nor may the spatial distribution adjustment described above be used to suppress spatial distribution fluctuations in the first optical signal caused by atmospheric turbulence. For example, the power adjustment described above may be used to amplify or reduce the power of the first optical signal by a fixed ratio.
[0061] In summary, in the communication device provided in this application embodiment, the adjustment unit can adjust the power and spatial distribution of the first optical signal received by the optical antenna from space, and then transmit the first optical signal with adjusted power and spatial distribution to the detection unit for detection. In this way, based on the adjustment unit's functions of adjusting the power and spatial distribution of the first optical signal, fluctuations in the first optical signal can be reduced, and communication stability can be improved.
[0062] Optionally, the power adjustment component includes at least one of a VOA and an optical amplifier. For example, the power adjustment component includes a VOA, or it includes an optical amplifier, or it includes both a VOA and an optical amplifier. The VOA can adjust the upper limit of the power of the first optical signal so that the upper limit of the power of the first optical signal is within a target power range; the optical amplifier can adjust the lower limit of the power of the first optical signal so that the lower limit of the power of the first optical signal is within a target power range. The optical amplifier can be a multimode optical amplifier or a few-mode optical amplifier. The multimode optical amplifier supports simultaneous power amplification of hundreds or thousands of light modes, while the few-mode optical amplifier supports simultaneous power amplification of 2 to 10 light modes.
[0063] Optionally, the aforementioned spatial distribution adjustment component includes a homogenizer or other devices capable of adjusting the spatial distribution of light (such as a spatial light modulator, a lens group with adjustable spatial distribution of light, etc.).
[0064] A homogenizer can include at least one of homogenizing optical fiber and a spatial optical field homogenizer. A spatial optical field homogenizer can be a diffuser, a diffractive optical element, a phase plate, a grating, an array lens (which can be called an array microlens), etc. When the spatial distribution adjustment component is a spatial optical field homogenizer, there is no need for an optical fiber connection between the spatial distribution adjustment component and other components in the communication equipment (such as a detection unit or a power adjustment component).
[0065] The aforementioned VOA, optical amplifier, homogenizing fiber, and spatial optical field homogenizer are all mature devices with simple structures and low cost. Therefore, compared to... Figure 2 The solution provided in this application embodiment has a lower cost. Furthermore, this application does not employ feedback regulation to adjust the power and spatial distribution of the first optical signal; therefore, even in strong turbulence scenarios, the communication device can still adapt to changes in the first optical signal, thereby effectively adjusting its power and spatial distribution.
[0066] Optionally, such as Figure 4 As shown, in the communication device provided in the foregoing embodiments (such as...) Figure 3Based on the communication device shown, the adjustment unit 032 further includes a multimode optical fiber 0323, and the power adjustment component 0321 is disposed on the multimode optical fiber 0323; the multimode optical fiber 0323 is used to transmit a first optical signal; the power adjustment component 0321 is used to adjust the power of the first optical signal transmitted in the multimode optical fiber 0323. When the spatial distribution adjustment component 0322 is a homogenizing optical fiber, the homogenizing optical fiber is connected to the multimode optical fiber 0323. At this time, the homogenizing optical fiber can be a multimode homogenizing optical fiber or a few-mode homogenizing optical fiber. Among them, the multimode optical fiber supports the simultaneous transmission of hundreds or thousands of modes of light, and the few-mode optical fiber supports the simultaneous transmission of 2 to 10 modes of light. In this embodiment, the homogenizing optical fiber is a multimode homogenizing optical fiber as an example.
[0067] from Figure 4 As can be seen, the first optical signal received by the optical antenna 031 from space (free space) is transmitted to the multimode optical fiber 0323 in the adjustment unit 032. Then, the power adjustment component 0321 adjusts the power of the first optical signal transmitted in the multimode optical fiber 0323. Since the optical signal received by the optical antenna 031 from space (free space) is a multimode optical signal, the first optical signal is also a multimode optical signal. Using the multimode optical fiber 0323 to transmit the first optical signal results in high coupling efficiency. The multimode optical fiber 0323 can efficiently transmit the first optical signal, which exhibits characteristics such as fragmentation, jitter, broadening, and angular arrival fluctuations after atmospheric interference. When the homogenizing fiber is also a multimode homogenizing fiber, the coupling efficiency of the first optical signal in the multimode homogenizing fiber is also high.
[0068] Furthermore, when the adjustment unit 032 includes a multimode fiber 0323, the first optical signal, when transmitted through the multimode fiber 0323, will excite higher-order modes of different orders. These excited modes correspond to different spot sizes and divergence angles. If the first optical signal passes sequentially through the power adjustment component 0321 and the spatial distribution adjustment component 0322, then during the transmission of the first optical signal from the multimode fiber 0323, the first optical signal undergoes power adjustment. After being output from the multimode fiber 0323, the first optical signal can also undergo spatial distribution adjustment in the spatial distribution adjustment component 0322, so as to stabilize the spot size and divergence angle of the different modes of the first optical signal. Moreover, by having the first optical signal undergo power adjustment first and then spatial distribution adjustment, the problem of the first optical signal's spatial distribution stability decreasing due to power adjustment after spatial distribution adjustment being altered can be avoided. If the first optical signal passes through the spatial distribution adjustment component 0322 and the power adjustment component 0321 in sequence, the size and divergence angle of the first optical signal spot will be stable after the spatial distribution adjustment. Even if it passes through the multimode fiber 0323, it will still stably excite a fixed higher-order mode, thus making the size and divergence angle of the first optical signal output by the multimode fiber 0323 relatively stable.
[0069] Figure 4 Taking the spatial distribution adjustment component 0322 as the homogenizing fiber, and the first optical signal passing sequentially through the power adjustment component 0321 and the spatial distribution adjustment component 0322 as an example. When the spatial distribution adjustment component 0322 is a spatial light homogenizer, Figure 4 The communication equipment shown is as follows Figure 5 As shown. When the first optical signal passes sequentially through the spatial distribution adjustment component 0322 and the power adjustment component 0321, Figure 5 The communication equipment shown is as follows Figure 6 As shown. It is understood that the adjustment unit 032 may also not include the multimode fiber 0323, and this application embodiment does not limit this.
[0070] Furthermore, such as Figure 4 As shown, the communication device provided in this application embodiment may further include a coupling unit for coupling the first optical signal output by the adjustment unit 032 to the detection unit 033. For example, the coupling unit includes a focusing lens group 034, which is located in the optical path between the adjustment unit 032 and the detection unit 033. The focusing lens group 034 is used to focus the first optical signal transmitted in the optical path between the adjustment unit 032 and the detection unit 033; or, in other words, the focusing lens group 034 is used to focus the first optical signal after power adjustment and spatial distribution adjustment before transmitting it to the detection unit 033.
[0071] By focusing the light through the focusing lens group 034, the spot size of the first optical signal after power adjustment and spatial distribution adjustment is reduced, allowing the communication equipment to use a detection unit 033 with a smaller target surface. Generally, the higher the rate of the first optical signal, the smaller the target surface of the detection unit 033 used in the communication equipment. The focusing through the focusing lens group 034 enables the communication equipment to be suitable for receiving first optical signals with higher rates. Furthermore, when the communication equipment includes multimode fiber, the spot size of the optical signal output from the multimode fiber is relatively large. The focusing through the focusing lens group 034 reduces the spot size of the first optical signal, allowing it to hit the target surface of the detection unit 033 and be effectively transmitted to it.
[0072] Focusing lens group 034 may include one or more focusing lenses. Figure 4 Taking the focusing lens group 034, which includes multiple focusing lenses 0341, as an example, these multiple focusing lenses 0341 can be divided into multi-stage focusing lenses 0341 arranged at intervals along the optical path from the adjustment unit 032 to the detection unit 033. The first-stage focusing lens 0341 closest to the detection unit 033 can be fitted into the detection unit 033. In this case, the divergence angle of the first optical signal transmitted from the focusing lens group 034 to the detection unit 033 is small, thus supporting a smaller detection surface of the detection unit 033, making the communication device suitable for receiving first optical signals with higher reception rates.
[0073] It is understood that the first-stage focusing lens 0341, which is close to the detection unit 033 in the multi-stage focusing lens 0341, may also be spaced apart from the detection unit 033. This application embodiment does not limit this.
[0074] The refractive index of the first-stage focusing lens 0341 closest to the detection unit 033 in the multi-stage focusing lens 0341 can be greater than 1.7. It can be seen that the first-stage focusing lens 0341 closest to the detection unit 033 in the multi-stage focusing lens 0341 has a high refractive index. In this way, the divergence angle of the first optical signal transmitted from the focusing lens group 034 to the detection unit 033 can be smaller, and it can also support the detection surface of the detection unit 033 to be smaller, so that the communication equipment can be used to receive first optical signals with a high receiving rate.
[0075] Of course, the refractive index of the first-stage focusing lens 0341, which is closer to the detection unit 033 in the multi-stage focusing lens 0341, can also be less than 1.7. For example, the refractive index can be 1.5, 1.6, etc. This application embodiment does not limit this.
[0076] The above embodiments use a communication device to receive a first optical signal as an example. Optionally, the communication device may also have the function of transmitting a second optical signal. For example, please refer to... Figure 7 ,exist Figure 3 Based on this, the communication equipment also includes: a second beam splitting unit 035 and a transmitting unit 036; the aforementioned optical antenna 031 is used to transmit the first optical signal to the adjustment unit 032 through the second beam splitting unit 035; the transmitting unit 036 is used to transmit a second optical signal to the second beam splitting unit 035, the wavelength of the second optical signal being different from the wavelength of the first optical signal; the second beam splitting unit 035 is used to transmit the second optical signal to the optical antenna 031; the optical antenna 031 is also used to transmit the second optical signal into space (free space). When the optical antenna 031 needs to receive both the first and second optical signals, it can employ a beam reducer or other device capable of receiving spatial light to receive the first optical signal, and a beam expander or other device capable of transmitting spatial light to transmit the second optical signal.
[0077] As can be seen, the communication device provided in this application embodiment is a transceiver integrated device. The optical antenna 031 in this communication device can transmit the received first optical signal to the second beam splitter 035, and the transmitting unit 036 in the communication device can also transmit a second optical signal to the second beam splitter 035. Since the wavelengths of the first and second optical signals are different, the second beam splitter 035 can transmit the first optical signal to the adjustment unit 032 based on the wavelength difference. This allows the adjustment unit 032 to perform power adjustment and spatial distribution adjustment on the first optical signal, and the detection unit 033 to detect the first optical signal after power adjustment and spatial distribution adjustment. The second beam splitter 035 can also transmit the second optical signal to the optical antenna 031 based on the wavelength difference, so that the optical antenna 031 can transmit the second optical signal.
[0078] in addition, Figure 7 The communication device shown may also include a focusing lens group ( Figure 7 (not shown in the text), but this application does not limit this aspect in the embodiments.
[0079] Optionally, an optical amplifier (not shown in the figures) may also be provided between the transmitting unit 036 and the second beam splitting unit 035. The optical amplifier is used to amplify the power of the second optical signal transmitted from the transmitting unit 036 to the second beam splitting unit 035, so as to improve the transmission reliability and transmission distance of the second optical signal.
[0080] If the entire adjustment unit 032 and its subsequent components (such as the focusing lens group 034 and the detection unit 033) are referred to as the anti-atmospheric interference receiving module, then the structure of the communication device provided in this application embodiment can be as follows: Figure 8 As shown.
[0081] In the above embodiments, the first optical signal may have one wavelength; it is understood that the first optical signal may also have multiple wavelengths. When the first optical signal has multiple wavelengths, it can carry more services. The following will combine... Figure 9 The scenario where the first optical signal has multiple wavelengths is described. Furthermore, regardless of whether the first optical signal has one or multiple wavelengths, the second optical signal can have one or more wavelengths. When the second optical signal has multiple wavelengths, the aforementioned transmitting unit 036 includes multiple transmitting modules 036 corresponding one-to-one with the multiple wavelengths of the second optical signal. Each transmitting module 036 is used to transmit light of the corresponding wavelength to the second beam splitting unit 035.
[0082] like Figure 9 As shown, when the first optical signal has multiple wavelengths, the detection unit 033 includes multiple detectors 0331, and the multiple wavelengths of the first optical signal correspond one-to-one with the multiple detectors 0331. Figure 9 Taking n detectors 0331 and n wavelengths as an example, where n > 1. The communication equipment also includes a first optical splitting unit 037. Figure 9 by Figure 7 The communication device shown also includes a first optical splitting unit 037 as an example. It can be understood that any communication device provided in the embodiments of this application (e.g., Figure 3 , Figure 4 The communication devices shown may also include a first optical splitting unit 037. Please continue to refer to [the relevant documentation]. Figure 9 The first beam splitting unit 037 is located on the optical path between the adjustment unit 032 and the detection unit 033. The first beam splitting unit 037 is used to receive the first optical signal after power adjustment and spatial distribution adjustment, and transmit the components of multiple wavelengths in the first optical signal after power adjustment and spatial distribution adjustment to the corresponding detectors 0331 respectively. Each detector 0331 is used to detect the component of the corresponding wavelength in the first optical signal after power adjustment and spatial distribution adjustment.
[0083] Detector 0331 can be a photodetector such as an avalanche photodiode (APD) or a phototransistor.
[0084] Optionally, the plurality of detectors 0331 can be arranged in an array. In this case, the first-level focusing lens closest to the detection unit 033 in the multi-stage focusing lens includes a plurality of focusing lenses 0341. The plurality of focusing lenses 0341 correspond one-to-one with the plurality of detectors 0331, and any one of the plurality of focusing lenses 0341 is located in the optical path between the adjustment unit 032 and the corresponding detector 0331. It is understood that the plurality of detectors 0331 may not be arranged in an array. For example, these detectors 0331 may be arranged irregularly, and this embodiment of the application does not limit this.
[0085] in addition, Figure 9 Taking the Sino-Israeli communication equipment including the second optical splitting unit 035 and the transmitting unit 036 as an example, Figure 9 The communication device shown may also exclude the second optical splitting unit 035 and the transmitting unit 036.
[0086] In the above embodiments, the adjustment unit 032 is used to adjust the power and spatial distribution of the first optical signal before transmitting it to the detection unit 033. It is understood that in the various embodiments provided in this application, the adjustment unit 032 may also adjust the power of the first optical signal (without adjusting the spatial distribution) before transmitting it to the detection unit 033, or the adjustment unit 032 may also adjust the spatial distribution of the first optical signal (without adjusting the power) before transmitting it to the detection unit 033.
[0087] This application also provides a communication system, which includes: a first device and a second device (such as...). Figure 1 (as shown); the first device is used to transmit a first optical signal into space (free space); the second device is used to receive the first optical signal from space (free space), and the second device can be any communication device provided in the embodiments of this application (such as...). Figure 3 , Figure 4 or Figure 7 (The communication device shown). The second device can also transmit a second optical signal into space (free space), and correspondingly, the first device can receive the second optical signal from space (free space). The structure and function of the second device can refer to the structure and function of the first device, and will not be described in detail here.
[0088] In this application, the terms “first” and “second” are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0089] It should be noted that all optical signals involved in this application are authorized by the user or fully authorized by all parties, and the collection, use, and processing of related business beams must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, the optical signals involved in this application were all obtained under full authorization.
[0090] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered 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. A communication device, characterized in that, include: Optical antenna, adjustment unit, and detection unit; The optical antenna is used to receive a first optical signal transmitted in space and transmit the first optical signal to the adjustment unit; The adjustment unit is used to adjust the power and spatial distribution of the first optical signal and then transmit it to the detection unit; The detection unit is used to detect the first optical signal after the power adjustment and the spatial distribution adjustment.
2. The communication device according to claim 1, characterized in that, The detection unit is used to detect optical signals within the target power range, and the power adjustment is used to adjust the power of the first optical signal to the target power range.
3. The communication device according to claim 1 or 2, characterized in that, The spatial distribution adjustment is used to improve the uniformity and stability of the spatial distribution of the first optical signal.
4. The communication device according to any one of claims 1 to 3, characterized in that, The first optical signal is sequentially processed by the power adjustment and the spatial distribution adjustment.
5. The communication device according to any one of claims 1 to 4, characterized in that, The adjustment unit includes: a power adjustment component and a spatial distribution adjustment component; The power adjustment component is used to adjust the power of the first optical signal; The spatial distribution adjustment component is used to adjust the spatial distribution of the first optical signal.
6. The communication device according to claim 5, characterized in that, The power adjustment component includes at least one of a variable optical attenuator (VOA) and an optical amplifier.
7. The communication device according to claim 5 or 6, characterized in that, The spatial distribution adjustment component includes a homogenizer.
8. The communication device according to any one of claims 5 to 7, characterized in that, The adjustment unit also includes a multimode optical fiber, and the power adjustment component is disposed on the multimode optical fiber; The multimode optical fiber is used to transmit the first optical signal; The power adjustment component is used to adjust the power of the first optical signal transmitted in the multimode optical fiber.
9. The communication device according to any one of claims 1 to 8, characterized in that, The communication device further includes a focusing lens group located in the optical path between the adjustment unit and the detection unit.
10. The communication device according to claim 9, characterized in that, The focusing lens group includes multiple levels of focusing lenses arranged at intervals along the optical path from the adjustment unit to the detection unit, wherein the first-level focusing lens closest to the detection unit is in contact with the detection unit.
11. The communication device according to claim 9 or 10, characterized in that, The focusing lens group includes multiple levels of focusing lenses arranged at intervals along the optical path from the adjustment unit to the detection unit, wherein the refractive index of the first-level focusing lens closest to the detection unit is greater than 1.
7.
12. The communication device according to any one of claims 1 to 11, characterized in that, The detection unit includes multiple detectors, and the first optical signal has multiple wavelengths that correspond one-to-one with the multiple detectors; The communication device further includes a first beam splitting unit, which is located on the optical path between the adjustment unit and the detection unit; the first beam splitting unit is used to receive the first optical signal after the power adjustment and the spatial distribution adjustment, and to transmit the components of the plurality of wavelengths in the first optical signal after the power adjustment and the spatial distribution adjustment to the corresponding detectors respectively; The detector is used to detect the components of the corresponding wavelength after the power adjustment and the spatial distribution adjustment.
13. The communication device according to claim 12, characterized in that, The multiple detector arrays are arranged in a specific configuration; The communication device includes: a multi-stage focusing lens arranged at intervals in the optical path between the adjustment unit and the detection unit, wherein the first-stage focusing lens closest to the detection unit includes multiple focusing lenses; Each of the plurality of focusing lenses corresponds one-to-one with the plurality of detectors, and any one of the plurality of focusing lenses is located on the optical path between the adjustment unit and the corresponding detector.
14. The communication device according to any one of claims 1 to 13, characterized in that, The communication device further includes: a second optical splitting unit and a transmitting unit; The optical antenna is used to transmit the first optical signal to the adjustment unit through the second beam splitter; The transmitting unit is used to transmit a second optical signal to the second beam splitting unit, the wavelength of the second optical signal being different from the wavelength of the first optical signal; The second beam splitter is used to transmit the second optical signal to the optical antenna; The optical antenna is also used to transmit the second optical signal into space.
15. The communication device according to any one of claims 1 to 14, characterized in that, The power adjustment is used to suppress power fluctuations of the first optical signal caused by atmospheric turbulence, and the spatial distribution adjustment is used to suppress spatial distribution fluctuations of the first optical signal caused by atmospheric turbulence.
16. A communication system, characterized in that, The communication system includes: a first device and a second device; The first device is used to transmit a first optical signal into space; The second device is used to receive the first optical signal from space, and the second device includes the communication device according to any one of claims 1 to 15.