An underwater optical communication optical power range and rate adaptive method and an underwater optical communication device

Abstract

The present invention discloses an underwater optical communication optical power range and rate adaptive method, which includes: the optical paths of a first communication end and a second communication end are aligned, and the first communication end selects the fiber laser with the maximum output power as the preset transmitting end; the second communication end receives the optical communication signal of the preset transmitting end, selects a photodetector according to a first rule, and selects a fiber laser according to a second rule; after the first communication end receives the optical communication signal of the second transmitting end, it selects a photodetector according to the first rule, and selects a fiber laser according to the second rule to complete the preliminary connection between the first communication end and the second communication end. Without relying on an optical power meter and other devices for informing the equivalent attenuation of optical power, the present invention uses multi-stage lasers for transmission and multi-stage photodetectors for reception, and can adaptively adjust the output power of the optical transmitting end and the power range of the receiving end, so as to establish underwater optical communication under a large change in the dynamic range of optical power.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and more specifically, to an underwater optical communication optical power range and rate adaptive method and an underwater optical communication device. Background Art

[0002] For the detection and protection of the marine ecological environment, the development and utilization of marine resources, the security protection of marine territory, etc., the support of a communication network is required. However, radio communication has extremely high attenuation in water, and the rate of low-frequency communication is low, which cannot meet the interaction of large amounts of information. In visible light communication technology, visible light in the blue-green (450nm - 570nm) band has strong penetration ability in seawater and low attenuation per unit distance, so it can meet the requirements of underwater wireless communication for high-speed communication technology.

[0003] However, in current underwater optical communication solutions, little attention has been paid to the engineering problem of the dynamic range of optical signals at the optical communication receiving end, and there is no practical solution for the adaptive adjustment of the communication rate of underwater optical communication. Most of the existing variable-rate underwater optical communication systems are based on the measurement of the optical power received at the receiving end by an optical power meter. As the underwater optical communication distance increases, the dynamic change range of the entire optical communication system also increases, and traditional optical power meters can no longer meet the requirements of the optical communication system. And during underwater optical communication, there is currently no other effective way to inform the distance between the transceiver ends and the current attenuation coefficient of water.

[0004] The current demand for wireless communication in underwater monitoring equipment is developing rapidly. While the communication distance and communication rate are increasing, the applicability of the communication distance and communication rate of underwater optical communication equipment is also increasing. Therefore, it is extremely urgent to study an underwater optical communication system that does not rely on an optical power meter and other underwater ranging equipment, can meet the conditions of large optical power dynamic range adaptation, and can also achieve communication rate adaptation, which has very important significance of the times. Summary of the Invention

[0005] In view of at least one defect or improvement requirement of the prior art, the present invention provides an underwater optical communication optical power range and rate adaptive method and an underwater optical communication device. Based on not relying on an optical power meter and other devices that inform the equivalent attenuation of optical power, by using multi-stage lasers for emission and multi-stage photodetectors for reception, the output power of the optical emission end and the power range of the receiving end can be adaptively adjusted to establish underwater optical communication under the change of a large optical power dynamic range.

[0006] To achieve the above object, according to the first aspect of the present invention, there is provided an underwater optical communication optical power range and rate adaptive method for optical communication connection between a first communication end and a second communication end in an underwater optical communication system, wherein both the first communication end and the second communication end include a transmitting end composed of N fiber lasers with different output powers and a receiving end composed of N photodetectors with different detection power ranges. The photodetectors of each communication end are numbered in descending order according to the maximum detection power, and the fiber lasers of each communication end are numbered in ascending order according to the output power. The number N of the fiber lasers and photodetectors is N≥3;

[0007] It is characterized in that the method includes:

[0008] S1. The optical paths of the first communication end and the second communication end are aligned. The first communication end selects the fiber laser with the maximum output power as the preset transmitting end;

[0009] S2. The second communication end receives the optical communication signal from the preset transmitting end and selects the corresponding photodetector as the second receiving end of the second communication end according to the first rule;

[0010] S3. The second communication end selects the corresponding fiber laser as the second transmitting end of the second communication end according to the second rule;

[0011] S4. After the first communication end receives the optical communication signal from the second transmitting end, it selects the photodetector as the first receiving end of the first communication end according to the first rule, and selects the fiber laser as the first transmitting end of the first communication end according to the second rule, completing the preliminary connection between the first communication end and the second communication end;

[0012] Wherein, the first rule is:

[0013] Select the photodetector with the maximum detectable power in the first communication end to receive the optical communication signal, read the preset range of this photodetector, and judge whether the output signal power of this photodetector is within the preset range; if the signal power is within the preset range, select this photodetector; if the signal power is greater than the preset range, report an error; if the signal power is less than the preset range, select the photodetector with the next number, and repeat the above judgment and selection steps until a photodetector with a suitable power range is selected.

[0014] The second rule is: extract the number of the selected photodetector and select the fiber laser with the same number as this photodetector.

[0015] Further, the above method for underwater optical communication optical power range and rate adaptation further includes:

[0016] The first communication end and the second communication end further respectively include a fiber optic combiner, a transmitting lens, a receiving lens, and a fiber optic splitter; the N fiber lasers of each communication end pass through the fiber optic combiner, and after being focused by the transmitting lens, emit communication light; after the receiving lens receives the communication light, it reaches the N photodetectors through the fiber optic splitter.

[0017] Further, the above method for underwater optical communication optical power range and rate adaptation further includes:

[0018] The detection power ranges of the photodetectors with adjacent numbers partially overlap.

[0019] Further, the above method for underwater optical communication optical power range and rate adaptation further includes:

[0020] The first rule further includes:

[0021] If the output signal power of the photodetector with the minimum detectable power is less than its preset range, an error is reported and subsequent steps are stopped.

[0022] Further, for the above method for underwater optical communication optical power range and rate adaptation, after the step S4, it further includes:

[0023] Extract the numbers of the fiber lasers in the first transmitting end and the second transmitting end, adjust the first transmitting end or the second transmitting end to the fiber laser corresponding to the smaller number, adjust the first receiving end or the second receiving end to the photodetector corresponding to the smaller number, and select the communication rate corresponding to the first transmitting end.

[0024] According to the second aspect of the present invention, there is also provided an underwater optical communication device, which includes:

[0025] A first communication end and a second communication end with optical path alignment;

[0026] Both the first communication end and the second communication end include a transmitting end composed of N fiber lasers with different output powers and a receiving end composed of N photodetectors with different detection power ranges. The photodetectors of each communication end are numbered in descending order according to the maximum detection power, and the fiber lasers of each communication end are numbered in ascending order according to the output power. The number N of the fiber lasers and photodetectors is N≥3;

[0027] The first communication end and the second communication end complete preliminary connection according to the following rules:

[0028] S1. The optical paths of the first communication terminal and the second communication terminal are aligned. The first communication terminal selects the fiber laser with the maximum output power as the preset transmitting end.

[0029] S2. The second communication terminal receives the optical communication signal from the preset transmitting end and selects the corresponding photodetector according to the first rule as the second receiving end of the second communication terminal.

[0030] S3. The second communication terminal selects the corresponding fiber laser according to the second rule as the second transmitting end of the second communication terminal.

[0031] S4. After the first communication terminal receives the optical communication signal from the second transmitting end, it selects the photodetector according to the first rule as the first receiving end of the first communication terminal, and selects the fiber laser according to the second rule as the first transmitting end of the first communication terminal, completing the preliminary connection between the first communication terminal and the second communication terminal.

[0032] Wherein, the first rule is:

[0033] Select the photodetector with the maximum detectable power in the first communication terminal to receive the optical communication signal, read the preset range of this photodetector, and judge whether the output signal power of this photodetector is within the preset range; if the signal power is within the preset range, select this photodetector; if the signal power is greater than the preset range, report an error; if the signal power is less than the preset range, select the photodetector with the next number, and repeat the above judgment and selection steps until a photodetector with a suitable power range is selected.

[0034] The second rule is: Extract the number of the selected photodetector and select the fiber laser with the same number as this photodetector.

[0035] Further, the above underwater optical communication device further includes:

[0036] The first communication terminal and the second communication terminal respectively further include a fiber combiner, a transmitting lens, a receiving lens and a fiber splitter; the N fiber lasers of each communication terminal pass through the fiber combiner and emit communication light after being focused by the transmitting lens; after the receiving lens receives the communication light, it reaches the N photodetectors through the fiber splitter.

[0037] Further, the above underwater optical communication device further includes:

[0038] The detection power ranges of the photodetectors with adjacent numbers partially overlap.

[0039] Further, the above underwater optical communication device further includes:

[0040] The first rule further includes:

[0041] If the output signal power of the photodetector with the minimum detectable power is less than its preset range, an error is reported and subsequent steps are stopped.

[0042] Further, for the above underwater optical communication device, after the step S4, it further includes:

[0043] Extract the numbers of the fiber lasers in the first transmitting end and the second transmitting end, adjust the first transmitting end or the second transmitting end to the fiber laser corresponding to the smaller number, adjust the first receiving end or the second receiving end to the photodetector corresponding to the smaller number, and select the communication rate corresponding to the first transmitting end.

[0044] Generally speaking, compared with the prior art by the above technical solution conceived by the present invention, the following beneficial effects can be achieved:

[0045] (1) An underwater optical communication optical power range and rate adaptive method provided by the present invention, based on not relying on an optical power meter and other devices for informing the equivalent attenuation of optical power, uses multi-stage lasers for transmission and multi-stage photodetectors for reception, can adaptively adjust the output power of the optical transmitting end and the power range of the receiving end, and realizes the establishment of underwater optical communication under a large dynamic range change of optical power.

[0046] (2) An underwater optical communication optical power range and rate adaptive method provided by the present invention, after adaptively adjusting the output power of the optical transmitting end and the power range of the receiving end, also uses a communication rate adaptive control algorithm and process, and can realize the automatic adjustment of the highest available communication rate of the underwater communication system under the current communication environment conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0048] Figure 1 It is a schematic flowchart of an underwater optical communication optical power range and rate adaptive method provided by an embodiment of the present invention;

[0049] Figure 2 It is a schematic diagram of an underwater optical communication device provided by an embodiment of the present invention;

[0050] Figure 3This is a schematic diagram of the specific implementation process of an underwater optical communication optical power range and rate adaptation method provided by an embodiment of the present invention;

[0051] Figure 4 This is a schematic diagram of the communication rate selection of an underwater optical communication optical power range and rate adaptation method provided by an embodiment of the present invention. Specific implementation manners

[0052] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] The terms "first", "second", "third", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0054] As Figure 1 shown, as the first embodiment of the present invention, an underwater optical communication optical power range and rate adaptation method is provided for optical communication connection between a first communication end and a second communication end in an underwater optical communication system, wherein both the first communication end and the second communication end include a transmitting end composed of N fiber lasers with different output powers and a receiving end composed of N photodetectors with different detection power ranges. The photodetectors of each communication end are numbered in descending order according to the maximum detection power, and the fiber lasers of each communication end are numbered in ascending order according to the output power. The number N of the fiber lasers and photodetectors is N≥3;

[0055] It is characterized in that the method includes:

[0056] S1. The optical paths of the first communication end and the second communication end are aligned, and the first communication end selects the fiber laser with the maximum output power as the preset transmitting end;

[0057] S2. The second communication end receives the optical communication signal of the preset transmitting end and selects the corresponding photodetector as the second receiving end of the second communication end according to the first rule;

[0058] S3. The second communication end selects a corresponding fiber laser as the second transmitting end of the second communication end according to the second rule;

[0059] S4. After receiving the optical communication signal from the second transmitting end, the first communication end selects a photodetector as the first receiving end of the first communication end according to the first rule, and selects a fiber laser as the first transmitting end of the first communication end according to the second rule, thus completing the preliminary connection between the first communication end and the second communication end;

[0060] Wherein, the first rule is:

[0061] Select the photodetector with the largest detectable power in the first communication end to receive the optical communication signal, read the preset range of this photodetector, and judge whether the output signal power of this photodetector is within the preset range; if the signal power is within the preset range, select this photodetector; if the signal power is greater than the preset range, report an error; if the signal power is less than the preset range, select the photodetector with the next number, and repeat the above judgment and selection steps until a photodetector with a suitable power range is selected.

[0062] The second rule is: extract the number of the selected photodetector, and select a fiber laser with the same number as this photodetector.

[0063] An underwater optical communication optical power range and rate adaptive method provided by the present invention, without relying on an optical power meter and other devices for informing the equivalent attenuation of optical power, uses multi-stage lasers for transmission and multi-stage photodetectors for reception, can adaptively adjust the output power of the optical transmitting end and the power range of the receiving end, and realizes the establishment of underwater optical communication under a large dynamic range change of optical power.

[0064] For the underwater optical communication optical power range and rate adaptive method provided by the present invention, the photodetector should first select the photodetector with the largest detectable power for reception, so as to avoid damaging the low-power photodetector when the signal optical power is large. The adaptive adjustment method is to sequentially reduce the detection power range of the photodetector, try and select from large to small in turn, and if there is a suitable one, select it as the receiving end, and if not, continue to select.

[0065] For the selection of fiber lasers, the method provided by the present invention is that when the photodetector with the largest detectable power is selected, the fiber laser with the smallest power is selected; when the photodetector with the second largest detectable power is selected, the fiber laser with the second smallest power is selected; that is, the photodetector and the fiber laser correspond one by one in the form of large to small and small to large. The larger the detectable power of the selected photodetector, the smaller the power of the corresponding fiber laser.

[0066] Furthermore, this embodiment further includes:

[0067] The first communication end and the second communication end respectively further include an optical fiber combiner, a transmitting lens, a receiving lens, and an optical fiber splitter; the N fiber lasers of each communication end pass through the optical fiber combiner and emit communication light after being focused by the transmitting lens; after the receiving lens receives the communication light, it reaches the N photodetectors through the optical fiber splitter.

[0068] Furthermore, this embodiment further includes:

[0069] The detection power ranges of the photodetectors with adjacent numbers partially overlap.

[0070] Theoretically speaking, when the detection power of the previous photodetector is less than the preset range, the signal power of the next photodetector will not be greater than its preset range. When this situation occurs, it indicates that the underwater optical communication environment is unstable, and it is not suitable for optical communication at this time.

[0071] Furthermore, this embodiment further includes:

[0072] The first rule further includes:

[0073] If the output signal power of the photodetector with the smallest detectable power is less than its preset range, an error will be reported and subsequent steps will be stopped.

[0074] Furthermore, in this embodiment, after the step S4, it further includes:

[0075] Extract the numbers of the fiber lasers in the first transmitting end and the second transmitting end, adjust the first transmitting end or the second transmitting end to the fiber laser corresponding to the smaller number, adjust the first receiving end or the second receiving end to the photodetector corresponding to the smaller number, and select the communication rate corresponding to the first transmitting end.

[0076] As Figures 2 - 4 shown, as the second embodiment of the present invention, a specific implementation manner of an adaptive method for an underwater optical communication system is provided.

[0077] In this embodiment, the transmitting end of underwater optical communication uses 4 or more laser light sources. The four lasers use four lasers with different power sizes. Since the greater the optical power of the laser, the lower the modulation rate, a single laser cannot simultaneously achieve large output optical power and high-speed signal modulation. The four lasers respectively correspond to four optical powers and four modulation rates, and all four lasers can meet the requirements of high-speed modulation and also meet the same low-rate modulation rate.

[0078] The four-channel laser is a pigtail output laser. After the outputs of the 4-channel lasers pass through a 4-in-1 fiber combiner, they form a single output. The pigtail of the combiner is output and then focused by a lens and emitted into the water. At the receiving end, after being received by a lens, the optical signal is coupled into the fiber, and then forms 4-channel optical signals through a 1-out-4 fiber splitter and enters four-channel photodetectors respectively. The four-channel photodetectors respectively correspond to the detection of optical power in four ranges. From the perspective of optical power magnitude, they are PIN, APD, PMT, and MPPC respectively, and the corresponding optical power ranges are 0 to -25 dBm (large), -20 dBm to -45 dBm, -40 dBm to -65 dBm, and -60 dBm to -85 dBm (small). The bandwidths of the four detectors also decrease as the detector sensitivity increases, and among them, MPPC can only support a bandwidth of several megahertz. To ensure the continuity of the system, there needs to be a certain overlap between the detection sensitivities of the four-channel photodetectors.

[0079] For the laser at the transmitting end, currently, the bandwidth of a laser with an output optical power of 1 W is only several megahertz. Selecting a low-power laser can achieve a bandwidth of 100 megahertz. However, the bandwidth of the laser is determined by the characteristics of the bare laser tube and cannot be changed by changing the driving circuit. Therefore, the transmitting end can only adopt a multi-channel laser solution. In the figure, the 4 lasers (LD) are arranged in ascending order of power as LD1 (small), LD2, LD3, LD4 (large).

[0080] See Figure 3 , the optical power adaptive adjustment process of underwater optical communication is shown in the figure. Both the first communication end and the second communication end include a set of transmitting and receiving ends for underwater optical communication. After the optical paths of the first communication end and the second communication end are aligned, first, the first communication end turns on the high-power laser (LD4) and repeatedly sends "communication starts, turn on LD4" at the lowest communication rate. At the same time, the second communication end turns on the PIN photodetector, and the post-processing circuit judges the magnitude of the output signal of the PIN. When it exceeds the artificially set maximum value, it turns on the laser LD1 and repeatedly sends the signal "turn on PIN: received optical power exceeds the upper limit"; when the magnitude of the output signal of the PIN is appropriate, it turns on the laser LD1 and repeatedly sends the signal "turn on PIN: normal communication can be carried out"; when the magnitude of the output signal of the PIN is less than the artificially set lower limit, it switches the detector, turns on the APD, and does not turn on any lasers for the time being.

[0081] After the APD is turned on, the post-processing circuit determines the magnitude of the output signal of the APD. If the output signal of the APD exceeds the upper limit set by humans at this time, an error is reported. Since there is a certain overlap between the detection range of the PIN and the detection range of the APD, when the output of the PIN is less than its own lower limit, the output of the APD cannot exceed the upper limit. If this phenomenon occurs, it can only be considered that the current underwater optical communication channel is changing violently, and optical communication is not suitable at this time; when the magnitude of the output signal of the APD is appropriate, the laser LD2 is turned on, and the signal "APD turned on: normal communication possible" is repeatedly sent; when the magnitude of the output signal of the APD is less than the lower limit set by humans, the detector is switched, the PMT is turned on, and no laser is turned on for the time being.

[0082] After the PMT is turned on, the post-processing circuit determines the magnitude of the output signal of the PMT. If the output signal of the PMT exceeds the upper limit set by humans at this time, an error is reported; when the magnitude of the output signal of the PMT is appropriate, the laser LD3 is turned on, and the signal "PMT turned on: normal communication possible" is repeatedly sent; when the magnitude of the output signal of the PMT is less than the lower limit set by humans, the detector is switched, the MPPC is turned on, and no laser is turned on for the time being.

[0083] After the MPPC is turned on, the post-processing circuit determines the magnitude of the output signal of the MPPC. If the output signal of the MPPC exceeds the upper limit set by humans at this time, an error is reported; when the magnitude of the output signal of the MPPC is appropriate, the laser LD4 is turned on, and the signal "MPPC turned on: normal communication possible" is repeatedly sent; when the magnitude of the output signal of the MPPC is less than the lower limit set by humans, the laser LD4 is turned on, and the second communication end is reported. At this time, the underwater optical communication distance exceeds the maximum available distance, or the attenuation on the underwater optical path exceeds the maximum acceptable attenuation value.

[0084] After the first communication end turns on the high-power laser (LD4), it waits for a period of time. During this waiting period, the second communication end will complete the above process. After that, like the second communication end, the first communication end determines which detector is currently available based on the magnitude of the output of each detection, except that the turned-on laser remains unchanged. When the first communication end selects the PIN and the output signal of the PIN also exceeds the upper limit, it reports that the optical signal is too large at this time and optical communication cannot be established, which means that the distance between the first communication end and the second communication end is too close.

[0085] After a suitable photodetector is selected at the first communication end, preliminary communication can be established. First, the signal content sent by the second communication end is parsed. When the signal content is "Turn on PIN: Received optical power exceeds the upper limit", and the available detector at the first communication end is PIN at this time, then the laser turned on at the first communication end is changed to LD1; when the available detector at the first communication end is APD at this time, then the laser turned on at the first communication end is changed to LD2. When establishing preliminary communication, the first communication end changes the signal sent to the information of turning on the selected detector and laser at itself, and continues to send at the lowest communication rate. After the first communication end makes a change, the second communication end can receive the signal from the first communication end, and then transmits the information of its own change to the first communication end. After the above process is completed, the first communication end and the second communication end complete the preliminary communication establishment.

[0086] See Figure 4 , after the first communication end and the second communication end complete the preliminary communication establishment, both sides can obtain the information of the laser and detector used by the other party currently. By using the selection of two sets of transmitting and receiving devices for mutual communication between the two sides, the attenuation magnitude of the optical signal in the current underwater optical communication can be estimated, and further the combination of the laser and detector with the highest available rate currently can be selected.

[0087] Furthermore, the parameters of the laser and photodetector selected in this embodiment are as follows:

[0088] Laser Optical Power & Rate Detector Available Range Bandwidth LD1 40mW, 100Mbps PIN 0dBm to -25dBm >100Mbps LD2 100mW, 50Mbps APD -20dBm to -45dBm >100Mbps LD3 400mW, 10Mbps PMT -40dBm to -65dBm 20Mbps LD4 1W, 1Mbps MPPC -60dBm to -85dBm 4Mbps

[0089] The specific implementation method for further selecting the combination of the laser and detector with the highest rate is as follows:

[0090] When the first communication end selects LD4 for transmission and PIN for reception, and normal communication is possible; when the second communication end selects LD1 for transmission and PIN for reception, and the power exceeds the upper limit. Then finally both the first communication end and the second communication end select LD1 for transmission and PIN for reception, and the selected communication rate is 100 Mbps.

[0091] When the first communication end selects LD4 for transmission and PMT for reception, and normal communication is possible; when the second communication end selects LD2 for transmission and APD for reception, and normal communication is possible. Then finally both the first communication end and the second communication end select LD2 for transmission and APD for reception, and the selected communication rate is 50 Mbps.

[0092] When the first communication end selects LD4 for transmission and MPPC for reception, and normal communication is possible; when the second communication end selects LD3 for transmission and PMT for reception, and normal communication is possible. Then finally both the first communication end and the second communication end select LD3 for transmission and PMT for reception, and the selected communication rate is 10 Mbps.

[0093] As a third embodiment of the present invention, an underwater optical communication device is further provided, which includes:

[0094] A first communication end and a second communication end with optical path alignment;

[0095] Both the first communication end and the second communication end include a transmitting end composed of N fiber lasers with different output powers and a receiving end composed of N photodetectors with different detection power ranges. The photodetectors of each communication end are numbered in descending order according to the maximum detection power, and the fiber lasers of each communication end are numbered in ascending order according to the output power. The number N of the fiber lasers and photodetectors is N≥3;

[0096] The first communication end and the second communication end complete the preliminary connection according to the following rules:

[0097] S1. The optical paths of the first communication end and the second communication end are aligned. The first communication end selects the fiber laser with the maximum output power as the preset transmitting end;

[0098] S2. The second communication end receives the optical communication signal of the preset transmitting end and selects the corresponding photodetector according to the first rule as the second receiving end of the second communication end;

[0099] S3. The second communication end selects the corresponding fiber laser as the second transmitting end of the second communication end according to the second rule;

[0100] S4. After the first communication end receives the optical communication signal of the second transmitting end, it selects the photodetector as the first receiving end of the first communication end according to the first rule and selects the fiber laser as the first transmitting end of the first communication end according to the second rule to complete the preliminary connection between the first communication end and the second communication end;

[0101] Among them, the first rule is:

[0102] Select the photodetector with the maximum detectable power in the first communication end to receive the optical communication signal, read the preset range of this photodetector, and judge whether the output signal power of this photodetector is within the preset range; if the signal power is within the preset range, select this photodetector; if the signal power is greater than the preset range, report an error; if the signal power is less than the preset range, select the photodetector with the next number, and repeat the above judgment and selection steps until a photodetector with a suitable power range is selected.

[0103] The second rule is: Extract the number of the selected photodetector and select the fiber laser with the same number as this photodetector.

[0104] Furthermore, this embodiment further includes:

[0105] The first communication end and the second communication end further respectively include an optical fiber combiner, a transmitting lens, a receiving lens, and an optical fiber splitter; the N optical fiber lasers of each communication end pass through the optical fiber combiner and emit communication light after being focused by the transmitting lens; after the receiving lens receives the communication light, it reaches the N photodetectors through the optical fiber splitter.

[0106] Furthermore, this embodiment further includes:

[0107] The detection power ranges of the photodetectors with adjacent numbers partially overlap.

[0108] Furthermore, this embodiment further includes:

[0109] The first rule further includes:

[0110] If the output signal power of the photodetector with the minimum detectable power is less than its preset range, an error is reported and subsequent steps are stopped.

[0111] Furthermore, after the step S4 in this embodiment, it further includes:

[0112] Extract the numbers of the optical fiber lasers in the first transmitting end and the second transmitting end, adjust the first transmitting end or the second transmitting end to the optical fiber laser corresponding to the smaller number, adjust the first receiving end or the second receiving end to the photodetector corresponding to the smaller number, and select the communication rate corresponding to the first transmitting end.

[0113] The foregoing are only exemplary embodiments of the present disclosure, and the scope of the present disclosure cannot be limited thereby. That is, any equivalent changes and modifications made in accordance with the teachings of the present disclosure still fall within the scope covered by the present disclosure. Those skilled in the art will readily think of other embodiments of the present disclosure after considering the specification and practicing the disclosure herein. The present invention aims to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common general knowledge or conventional technical means in the technical field not recorded in the present disclosure. The specification and embodiments are only regarded as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

[0114] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0115] Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An underwater optical communication optical power range and rate adaptive method for optical communication connection between a first communication end and a second communication end in an underwater optical communication system, where both the first communication end and the second communication end include a transmitting end composed of N fiber lasers with different output powers and a receiving end composed of N photodetectors with different detection power ranges. The photodetectors of each communication end are numbered in descending order according to the maximum detection power, and the fiber lasers of each communication end are numbered in ascending order according to the output power. The number of the fiber lasers and photodetectors N ≥ 3; It is characterized in that The method includes: S1. The optical paths of the first communication end and the second communication end are aligned. The first communication end selects the fiber laser with the maximum output power as the preset transmitting end; S2. The second communication end receives the optical communication signal from the preset transmitting end and selects the corresponding photodetector according to the first rule as the second receiving end of the second communication end; S3. The second communication end selects the corresponding fiber laser according to the second rule as the second transmitting end of the second communication end; S4. After the first communication end receives the optical communication signal from the second transmitting end, it selects a photodetector according to the first rule as the first receiving end of the first communication end, and selects a fiber laser according to the second rule as the first transmitting end of the first communication end, completing the preliminary connection between the first communication end and the second communication end; Among them, the first rule is: Select the photodetector with the maximum detectable power in the first communication end to receive the optical communication signal, read the preset range of this photodetector, and judge whether the output signal power of this photodetector is within the preset range; if the signal power is within the preset range, select this photodetector; if the signal power is greater than the preset range, report an error; if the signal power is less than the preset range, select the photodetector with the next serial number, and repeat the above judgment and selection steps until a photodetector with a suitable power range is selected; The second rule is: Extract the serial number of the selected photodetector and select the fiber laser with the same serial number as this photodetector; The first communication end and the second communication end respectively further include an optical fiber combiner, a transmitting lens, a receiving lens, and an optical fiber splitter; the N optical fiber lasers of each communication end pass through the optical fiber combiner and emit communication light after being focused by the transmitting lens; after the receiving lens receives the communication light, it reaches the N photodetectors through the optical fiber splitter; After the step S4, it further includes: Extract the serial numbers of the fiber lasers in the first transmitting end and the second transmitting end, adjust the first transmitting end or the second transmitting end to the fiber laser corresponding to the smaller serial number, adjust the first receiving end or the second receiving end to the photodetector corresponding to the smaller serial number, and select the communication rate corresponding to the first transmitting end.

2. The underwater optical communication optical power range and rate adaptive method according to claim 1, characterized in that: The detection power ranges of the photodetectors with adjacent serial numbers partially overlap.

3. The underwater optical communication optical power range and rate adaptive method according to claim 1, characterized in that: The first rule further includes: If the output signal power of the photodetector with the minimum detectable power is less than its preset range, report an error and stop the subsequent steps.

4. An underwater optical communication device, characterized in that, It includes: The first communication end and the second communication end with aligned optical paths; Both the first communication terminal and the second communication terminal include a transmitting end composed of N fiber lasers with different output powers and a receiving end composed of N photodetectors with different detection power ranges. The photodetectors of each communication terminal are numbered in descending order according to the maximum detection power, and the fiber lasers of each communication terminal are numbered in ascending order according to the output power. The number of the fiber lasers and photodetectors N ≥3; The first communication end and the second communication end complete the preliminary connection according to the following rules: S1. The optical paths of the first communication end and the second communication end are aligned. The first communication end selects the fiber laser with the maximum output power as the preset transmitting end; S2. The second communication end receives the optical communication signal from the preset transmitting end and selects the corresponding photodetector according to the first rule as the second receiving end of the second communication end; S3. The second communication end selects the corresponding fiber laser according to the second rule as the second transmitting end of the second communication end; After the first communication end receives the optical communication signal from the second transmitting end, an optical detector is selected according to the first rule as the first receiving end of the first communication end, and a fiber laser is selected according to the second rule as the first transmitting end of the first communication end, completing the preliminary connection between the first communication end and the second communication end; Wherein, the first rule is: Select the optical detector with the largest detectable power in the first communication end to receive the optical communication signal, read the preset range of this optical detector, and judge whether the output signal power of this optical detector is within the preset range; if the signal power is within the preset range, select this optical detector; if the signal power is greater than the preset range, report an error; if the signal power is less than the preset range, select the optical detector with the next number, and repeat the above judgment and selection steps until an optical detector with a suitable power range is selected; The second rule is: extract the number of the selected optical detector, and select the fiber laser with the same number as this optical detector; The first communication terminal and the second communication terminal further include a fiber optic combiner, a transmitting lens, a receiving lens, and a fiber optic splitter respectively; the N fiber lasers of each communication terminal pass through the fiber optic combiner, and after being focused by the transmitting lens, emit communication light; after the receiving lens receives the communication light, it reaches the N photoelectric detectors through the fiber optic splitter; After the step S4, it further includes: extracting the numbers of the fiber lasers in the first transmitting end and the second transmitting end, adjusting the first transmitting end or the second transmitting end to the fiber laser corresponding to the smaller number, adjusting the first receiving end or the second receiving end to the optical detector corresponding to the smaller number, and selecting the communication rate corresponding to the first transmitting end.

5. The underwater optical communication device according to claim 4, wherein: The detection power ranges of the adjacent-numbered optical detectors partially overlap.

6. The underwater optical communication device according to claim 4, wherein: The first rule further includes: If the output signal power of the optical detector with the smallest detectable power is less than its preset range, report an error and stop the subsequent steps.

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