Underwater equipment and communication systems

Abstract

To provide underwater equipment and a communication system, each enabling improvement of a service life of a submarine cable optical fiber communication system by installing backup pump laser.SOLUTION: Underwater equipment 100 includes a first optical fiber 110, a second optical fiber 120, a conventional pump laser 101, and at least one backup pump laser 102. The conventional pump laser 101 is used for providing pump light for a first optical amplification unit 150 located at the first optical fiber 110 and a second optical amplification unit 160 located at the second optical fiber 120. The backup pump laser 102 is used for performing output power compensation when an output power of the conventional pump laser 101 is less than a target output power. Each of the conventional pump laser 101 and the backup pump laser 102 are coupled to an input port of an optical device 130.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] This application relates to the field of optical communication technology, and more particularly to underwater equipment and communication systems. [Background technology]

[0002] As an important means of international communication, submarine cable communication systems are typically required by the industry to have a service life of 25 years, but in reality, submarine cable communication systems face the issue of system performance degradation due to device aging in the middle and later stages of their service life. Optical repeaters in submarine cable communication systems mainly use EDFA (Erbium Doped Fiber Amplifier) ​​optical amplification technology, and in communication systems composed of optical fiber amplifiers, aging of the pump laser is one of the main causes of performance degradation in submarine cable communication systems.

[0003] In the middle and later stages of the service life of a submarine cable communication system, the aging of pump lasers causes a decrease in the output power of optical repeaters. This, combined with the aging of other optical devices and increased wear due to aging of the circuit optical fiber, leads to a deterioration in the performance of the circuit OSNR (Optical Signal Noise Ratio), and in serious cases, can even cause service interruptions.

[0004] When the pump laser becomes obsolete, submarine cable communication systems can undergo construction maintenance by adding an extra optical repeater to the circuit, increasing the optical power of the circuit and improving the performance degradation of the system caused by aging. However, the maintenance process requires a work vessel to cut the submarine cable for maintenance, which takes a long time and causes an interruption to the operation of the entire system, and also results in high later-stage maintenance costs. Summary of the Invention [Problem to be solved by the invention]

[0005] The present application provides underwater equipment (underwater equipment) and a communication system, which solves the problem that when the performance of the pump laser in a submarine cable communication system deteriorates, the pump output power does not meet the output requirements, and the service life of the submarine cable communication system does not meet the standards. [Means for solving the problem]

[0006] In a first aspect, some embodiments of the present application provide an underwater device, the underwater device including a first optical fiber, a second optical fiber, a normal pump laser, and at least one backup pump laser; the normal pump laser is used to provide pump light to a first optical amplification unit located in a first optical fiber and a second optical amplification unit located in a second optical fiber; the normal pump laser and the backup pump laser are respectively connected to input ports of an optical device of the first optical fiber and / or the second optical fiber, wherein the optical device is used to optically couple the normal pump laser and the backup pump laser; the backup pump laser is used to compensate for the output power of the normal pump laser when the output power of the normal pump laser is smaller than a target output power, wherein the compensated output power is the output power lost by the normal pump laser in an aging state; The backup pump laser is configured to be in an off state before a first command is received, and to be activated to output pump light when the first command is received, wherein: The first command is a control command sent when the output power of the normal pump laser is smaller than the target output power. The present application provides at least one backup pump laser in the underwater equipment, so that when the normal pump laser becomes obsolete, the backup pump laser can be activated to compensate for the pump output power of the underwater equipment, thereby improving the service life of the submarine cable optical fiber communication.

[0007] In some possible embodiments, the backup pump laser is further configured to be in an off state before a second command is received, and to be activated to output pump light when a second command is received, wherein the second command is a control command sent when the aging value of the underwater equipment is greater than a threshold value, and the underwater equipment can compare the calculated aging value with the threshold value, and activate the backup pump laser to make the pump output power meet the output requirement.

[0008] In some possible embodiments, the conventional pump laser comprises a first pump laser and a second pump laser connected to the backup pump laser; an input port of a first fiber optic coupler of the first optical fiber is connected to the first pump laser, and an output port of the first fiber optic coupler of the first optical fiber is connected to the first optical amplification unit; The second pump laser and the backup pump laser are respectively connected to the input port of the optical device of the second optical fiber, and the output port of the optical device of the second optical fiber is connected to the second optical amplification unit, where the first pump laser is used to provide pump light to the first optical amplification unit located in the first optical fiber, and the second pump laser is used to provide pump light to the second optical amplification unit located in the second optical fiber. The number of backup pump lasers can be selected to be a certain percentage of the normal pump lasers after evaluation based on device reliability and system performance. By periodically arranging the backup pump lasers, some backup pump lasers can be selectively activated, thereby reducing costs.

[0009] In some possible embodiments, the underwater device includes at least two first pump lasers and two second pump lasers, each of the first pump lasers providing 50% of the energy to the first optical amplification unit, and each of the second pump lasers providing 50% of the energy to the second optical amplification unit; Alternatively, the underwater device includes at least four first pump lasers and four second pump lasers, each of which provides 25% of the energy to the first optical amplification unit, and each of which provides 25% of the energy to the second optical amplification unit. The underwater device is provided with a pump extra optical path, and two conventional pump lasers are redundant to each other. When one conventional pump laser is disabled, the other conventional pump laser provides pump light, and at the same time, a backup pump laser is activated in the single fiber pair 2x2 or 4x4 pump extra optical path, thereby increasing the pump power of all EDFA circuits through the 2x2 or 4x4 pump extra optical path.

[0010] In some possible embodiments, the backup pump laser is connected to only one of the second pump lasers of the underwater equipment, where a newly added backup pump laser is used to compensate for only the pump power reduced due to aging, and the backup pump laser is connected to only one normal pump laser of the underwater equipment, which can compensate for the pump output power and reduce costs.

[0011] In some possible embodiments, the first optical fiber and the second optical fiber belong to the same optical fiber pair, or the first optical fiber and the second optical fiber belong to different optical fiber pairs, and the first optical fiber can be used to transmit optical signals to a terrestrial base station at the opposite end, and the second optical fiber can be used to receive optical signals transmitted from the terrestrial base station at the opposite end.

[0012] In some possible embodiments, the optical device is a polarization beam combiner or an optical switch. The normal pump laser and the backup pump laser can be optically combined by a polarization beam combiner, and the pump laser and the backup pump laser can be strobed using an optical switch.

[0013] In some possible embodiments, one backup pump laser is provided for each of the conventional pump lasers, and the conventional pump laser and the backup pump laser are combined by a polarization beam combiner or an optical switch. By providing a backup pump laser for each of the conventional pump lasers of all underwater devices in the entire circuit, the space and granularity (precision) of the performance adjustment of the entire underwater device communication system can be improved.

[0014] In some possible embodiments, the underwater equipment is an optical repeater, and a backup pump laser is added to the optical repeater to compensate for the output power reduction caused by the aging of the normal pump laser, and improve the aging condition of the pump laser, so that the output power of the optical repeater meets the operating requirements, and the optical signal-to-noise ratio of the optical repeater is kept stable, thereby maintaining the stability of the transmission performance.

[0015] In a second aspect, the present application further provides an underwater device communication system, comprising the underwater device according to the first aspect, a first station used to transmit a first data optical signal to the underwater device via the first optical fiber; a second station used to transmit a second data optical signal to the underwater device via the second optical fiber; The underwater equipment is used to receive the first data optical signal, amplify the first data optical signal, and then output it to the second station, and is used to receive the second data optical signal, amplify the second data optical signal, and then output it to the first station. [Effects of the Invention]

[0016] As can be seen from the above technical solutions, some embodiments of the present application provide an underwater equipment and a communication system, the underwater equipment including a first optical fiber, a second optical fiber, a conventional pump laser, and at least one backup pump laser, the conventional pump laser is used to provide pump light to a first optical amplification unit located in the first optical fiber and a second optical amplification unit located in the second optical fiber, the conventional pump laser and the backup pump laser are respectively connected to input ports of an optical device of the first optical fiber and / or the second optical fiber, the optical device is used to optically couple the conventional pump laser and the backup pump laser, the backup pump laser is used to compensate for the output power of the conventional pump laser when the output power is lower than a target output power, the compensated output power is the output power lost by the conventional pump laser in an aging state, the backup pump laser is configured to be in an off state before a first command is received, and be activated to output pump light when the first command is received. The first command is a control command sent when the output power of the normal pump laser is lower than the target output power. By installing at least one backup pump laser in the underwater equipment, when the normal pump laser becomes obsolete, the backup pump laser can be activated to compensate for the pump output power of the underwater equipment, thereby improving the service life of the submarine cable optical fiber communication. [Brief explanation of the drawings]

[0017] In order to more clearly explain the technical solutions of the present application, the following briefly introduces the drawings that need to be used in the embodiments, and it is obvious that those skilled in the art can further derive other drawings based on these drawings without any creative efforts. [Figure 1] 1 is a structural schematic diagram of an underwater communication system. [Figure 2] 1 is a structural schematic diagram 1 of an underwater device according to some embodiments of the present application. [Figure 3] 2 is a structural schematic diagram 2 of an underwater device according to some embodiments of the present application. [Figure 4] 3 is a structural schematic diagram 3 of underwater equipment according to some embodiments of the present application. [Figure 5] 1 is a structural schematic diagram of an underwater device communication system according to some embodiments of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0018] The technical solutions of the present invention will be described clearly and completely in conjunction with the following examples, and it is obvious that the described examples are only some of the embodiments of the present invention, and not all of the embodiments, and all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative efforts fall within the scope of protection of the present invention.

[0019] The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying the relative importance or the number of the indicated technical features. Accordingly, a feature qualified with "first" or "second" may explicitly or implicitly include one or more of the aforementioned features. In the description of the present invention, "multiple" means two or more unless otherwise clearly and specifically limited. Furthermore, the terms "attached," "coupled," and "connected" should be understood broadly and may refer to, for example, a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0020] An underwater communication system is a system that is laid on the bottom of the sea or a lake, etc., to realize long-distance data communication. For example, the underwater communication system may include a submarine cable communication system.

[0021] As shown in Figure 1, submarine cable communication systems are an important means of international communication, and the industry typically requires a 25-year service life. However, in reality, submarine cable communication systems face the issue of system performance degradation due to device aging in the middle and later stages of their service life. Optical repeaters in submarine cable communication systems mainly use EDFA (Erbium Doped Fiber Amplifier) ​​optical amplification technology, and in communication systems composed of optical fiber amplifiers, aging of the pump laser is one of the main causes of performance degradation in submarine cable communication systems.

[0022] In the middle and later stages of the service life of a submarine cable communication system, the aging of pump lasers causes a decrease in the output power of optical repeaters. This, combined with the aging of other optical devices and increased wear due to aging of the circuit optical fiber, leads to a deterioration in the circuit OSNR (Optical Signal Noise Ratio) performance, and in serious cases, can even cause service interruptions.

[0023] In the related art, a significant derating design is adopted for the pump laser to suppress the aging tendency of the pump device, thereby extending the service life of the submarine cable optical fiber communication; however, the output current and output power of the pump laser are limited, which makes it impossible to fully utilize the performance of the device itself, resulting in a waste of device performance, and in serious cases, making it impossible for the system to operate at its optimum performance point.

[0024] In related technology, when the pump laser becomes obsolete, construction maintenance can be performed on the submarine cable communication system by adding an extra optical repeater to the circuit to increase the optical power of the circuit and improve the performance degradation of the system caused by aging. However, the maintenance process requires a work vessel to cut the submarine cable for maintenance, which not only causes an interruption to the operation of the entire system but also lengthens the maintenance time and incurs very high later maintenance costs.

[0025] In order to solve the problem that when the performance of the pump laser in a submarine cable communication system deteriorates, the pump output power does not meet the output requirement, and the service life of the submarine cable communication system does not meet the standard, some embodiments of the present application provide underwater equipment, and install at least one backup pump laser in the underwater equipment. When the normal pump laser is aging, the backup pump laser can be activated to compensate for the pump output power of the underwater equipment, thereby improving the service life of the submarine cable optical fiber communication.

[0026] Some embodiments of the present application provide an underwater device 100, the underwater device 100 including a first optical fiber 110, a second optical fiber 120, a conventional pump laser 101, and at least one backup pump laser 102; The conventional pump laser 101 is used to provide pump light to a first optical amplification unit 150 located in a first optical fiber 110 and a second optical amplification unit 160 located in a second optical fiber 120, and the conventional pump laser 101 and the backup pump laser 102 are respectively connected to input ports of an optical device 130 of the first optical fiber 110 and / or the second optical fiber 120, wherein the optical device 130 is used to optically couple the conventional pump laser 101 and the backup pump laser 102; The backup pump laser 102 is used to compensate for the output power of the normal pump laser 101 when the output power is lower than the target output power, and the compensated output power is the output power lost due to the aging of the normal pump laser 101. Note that the normal pump laser 101 operates normally throughout the entire service phase of the communication system, but the backup pump laser 102 does not operate at the initial stage of the communication system service, and is activated when a control command transmitted from the underwater device 100 is received, or activated based on an activation command transmitted from the ground base station.

[0027] In some embodiments, the backup pump laser 102 is configured to be in an off state before a first command is received, and to be activated to output pump light when a first command is received, where the first command is a control command sent when the output power of the normal pump laser 101 is smaller than a target output power. The underwater device 100 can detect the output power of the normal pump laser 101 or the underwater device 100 in real time, and activate the backup pump laser 102 when the output power is smaller than the target output power.

[0028] In some embodiments, the backup pump laser 102 is further configured to be in an off state before the second command is received and to be activated to generate the pump light when the second command is received. wherein the second command is a control command sent when the deterioration value of the underwater device 100 is greater than a threshold. The underwater device 100 is further configured to start up a backup pump laser 102 when the calculated deterioration value is greater than a threshold. Wherein, the first command and the second command may have the same priority, or the first command and the second command may have different priorities or may not be distinguished.

[0029] The aging value of the underwater device 100 can be obtained based on the bit error rate, optical signal-to-noise ratio, and loopback signal power of the underwater device 100, and other means.

[0030] The bit error rate (BER) is the ratio of the number of error bits to the total number of bits when an electrical signal is converted into an optical signal, transmitted through a WDM wavelength division multiplexing system, and then transmitted to the end of the link. The optical signal is converted back into an electrical signal by a receiver. The BER is a final value used to assess the quality of transmission. In some embodiments, the underwater device 100 detects the BER of the system's performance in real time. A higher BER indicates a greater degree of system deterioration.

[0031] The optical signal-to-noise ratio is defined as the ratio of optical signal power to noise power within an optical effective bandwidth of 0.1 nm. In some embodiments, the ground terminal can determine whether the system has aged based on changes in the optical signal-to-noise ratio (OSNR) of the receiving terminal's service optical signal, and can predict the system aging trend by monitoring the OSNR change trend in real time or by periodically testing and comparing the OSNR change.

[0032] In some embodiments, an OTDR (optical time-domain reflectometer) or COTDR (coherent optical time-domain reflectometer) device installed at the ground terminal can be used to intuitively detect gain changes in an RPT optical repeater. Based on the RPT gain change, it can be determined whether the pump laser has aged. The OTDR (optical time-domain reflectometer) testing principle involves pulse-modulating a laser and sending the test light to the optical transmission circuit under test through an optical directional coupler that can separate the emitted and received light. Due to the effect of Rayleigh scattering, the backscattered light returned from each part of the optical fiber (including optical fiber inhomogeneities, optical connectors, optical fiber joints, and optical fiber breaks or breakpoints) displays a continuous signal on the screen time base, i.e., the closer the signal, the further the signal, and the further the signal, and its intensity is proportional to the transmitted optical power at each point. As is apparent, the backward scattered light is separated and received by the optical coupler, and the horizontal axis corresponds to the time sequence of the arrival of the backward scattered light in the form of distance, the vertical axis indicates the intensity of the scattered light in dB, and the horizontal axis converts the round trip time of the light pulse into a scale of the optical fiber length, which can be used to directly observe the change in the optical power transmitted along the entire optical fiber circuit.

[0033] COTDR (Coherent Optical Time Domain Reflectometry) technology is a method for monitoring and measuring the underwater portion of a submarine cable communication system. It involves transmitting a probe optical pulse signal into an optical fiber. As the optical pulse travels through the optical fiber, back-scattered Rayleigh scattered light continues to be generated along the optical fiber. Reflections occur at connectors, mechanical connections, breaks, and the end of the optical fiber. Some of the back-scattered Rayleigh scattered light and the reflected light travel in the opposite direction along the optical fiber, returning to the source and being received by the probe of the COTDR meter. The operating status of the submarine optical cable and repeaters can be determined based on changes in the intensity of the received optical pulse.

[0034] In some embodiments, an optical fiber coupler 140 is connected to the output end of the optical amplification unit of the underwater equipment 100, and the optical fiber coupler 140 includes a first optical fiber coupler located on the first optical fiber 110 and a second optical fiber coupler located on the second optical fiber 120, among which: The first optical fiber coupler located in the second optical fiber 120 is used to receive the first reflected optical signal and send a portion of the first reflected optical signal to the second optical fiber coupler located in the second optical fiber 120, where the first reflected optical signal is obtained after the amplified first detected optical signal undergoes back-scattering Rayleigh scattering, and the second optical fiber coupler located in the second optical fiber 120 is used to receive the portion of the first reflected optical signal output from the first optical fiber coupler and send the portion of the first reflected optical signal toward the first station 200. An optical fiber coupler 140 is added to the output end of the first optical amplification unit 150 or the second optical amplification unit 160 of the underwater equipment 100, so as not to degrade the noise coefficient of the underwater equipment 100. A coupling connection is made between each pair of optical fibers inside the underwater equipment 100, i.e., a loopback path is set up, so that the backward Rayleigh scattering and / or reflected optical signal of the probe optical signal incident on the upstream link can be coupled to the downstream link, transmitted along the downstream optical fiber, and amplified by the downstream optical amplification unit as it passes through the underwater equipment 100, and transmitted in the reverse direction back to the ground terminal. This makes it easier for the probe of the COTDR meter to receive the probe optical signal, and the COTDR meter can detect the aging or failure of the normal pump laser, so that the backup pump laser can be activated in a timely manner, and the backup pump laser will output pump light to compensate for the pump output power of the underwater equipment 100.

[0035] In some embodiments of the present application, the detection method for detecting a submarine optical cable circuit using a COTDR (Coherent Optical Time Domain Reflectometry) instrument may include:

[0036] The submarine cable circuit detection device generates a detection signal and divides the detection signal input to the first optical amplification unit 150 into a first detection signal and a second detection signal. The two detection signals pass through different paths to detect the status of the optical amplification unit and the optical cable circuit connected between the optical amplification units.

[0037] The first detection signal is split and then directly coupled and looped back to the output end of the second optical amplification unit 160, which is in a direction opposite to that of the first optical amplification unit 150, to form a first loopback path, outputting a first detection loopback signal that is returned to the optical cable circuit. The first detection signal is split and then directly coupled and looped back to the output end of the second optical amplification unit 160, to form a first loopback path, outputting the first detection loopback signal to the upstream or downstream circuit trunk line. The first detection loopback signal is a directly coupled and looped back signal, and the output first detection loopback signal is measured to obtain the first detection loopback signal power. The second optical amplification unit 160 is in a direction opposite to that of the first optical amplification unit 150. For example, during downstream detection, the first optical amplification unit 150 is for downstream transmission, and the second optical amplification unit 160 is for upstream transmission. When the first optical amplification unit 150 is a downstream optical amplification unit, the status of the downstream submarine optical cable circuit can be detected based on the first detected loopback signal power and the second detected loopback signal power, and when the first optical amplification unit 150 is an upstream optical functional unit, the status of the upstream submarine optical cable circuit can be detected based on the first detected loopback signal power and the second detected loopback signal power.

[0038] The second detection signal passes through the first optical amplification unit 150 and then looped back to the output end of the second optical amplification unit 160 to form a second loopback path, outputting a second detection loopback signal. The second detection signal passes through the first optical amplification unit 150 and enters the optical cable circuit. The second detection signal that passed through the first optical amplification unit 150 is looped back to the output end of the second optical amplification unit 160 to form a second loopback path, outputting the second detection loopback signal to the upstream or downstream circuit trunk line. The second detection loopback signal is measured to obtain the second detection loopback signal power. The detection device transmits pulsed light, the first detection loopback signal is a pulse signal, and the second detection loopback signal is The power of the signal is determined by the return time and pulse width.

[0039] The status of the submarine optical cable circuit is detected based on the first detected loopback signal power and the second detected loopback signal power.

[0040] The number of backup pump lasers 102 in the underwater device 100 can be selected based on a certain ratio of the normal pump lasers 101 after evaluating the reliability of the device and the system performance.

[0041] In some embodiments, the underwater device 100 includes a plurality of conventional pump lasers 101, the conventional pump lasers 101 including a first pump laser and a second pump laser connected to the backup pump laser; an input port of a first optical fiber coupler of the first optical fiber 110 is connected to the first pump laser, and an output port of the first optical fiber coupler of the first optical fiber 110 is connected to the first optical amplification unit 150; a second pump laser and the backup pump laser 102 are respectively connected to input ports of an optical device 130 of the second optical fiber 120, and an output port of the optical device 130 of the second optical fiber 120 is connected to the second optical amplification unit 160; The first pump laser is used to provide pump light to a first optical amplification unit 150 located in a first optical fiber 110, and the second pump laser is used to provide pump light to a second optical amplification unit 160 located in a second optical fiber 120.

[0042] The first optical fiber 110 and the second optical fiber 120 may belong to the same optical fiber pair, or may belong to different optical fiber pairs. In some embodiments, the first optical fiber 110 may be used to transmit optical signals to a land base station at the opposite end, and the second optical fiber 120 may be used to receive optical signals transmitted from the land base station at the opposite end.

[0043] In some embodiments, the underwater device 100 includes at least two first pump lasers and two second pump lasers, each of the first pump lasers providing 50% of the energy to the first optical amplification unit 150 and each of the second pump lasers providing 50% of the energy to the second optical amplification unit 160; Alternatively, the underwater equipment 100 may include four first pump lasers or four second pump lasers, each of which provides 25% of the energy to the first optical amplification unit 150 and each of which provides 25% of the energy to the second optical amplification unit 160. That is, the outputs of the four pump lasers are combined via a combining unit and output to the four optical amplification units of two fiber pairs, with each pump laser providing 1 / 4 of the pump energy to each amplifier. In this case, the impact of one pump failure on the system optical signal-to-noise ratio is smaller. In this embodiment, the backup pump laser 102 is connected to only one of the second pump lasers of the underwater equipment 100. By providing a backup pump laser 102 for only one normal pump laser 101 of the underwater equipment 100, it is possible to compensate for the pump power loss due to aging and reduce costs.

[0044] As shown in Figure 2, the underwater device 100 adopts a single fiber pair 2x2 protection, that is, the two normal pump laser outputs are combined through one combiner to provide 50%: For example, the output of each fiber pair is fed to two optical amplifier units according to a 50% ratio. In addition to the two conventional pump lasers, one backup pump laser is added, and the backup pump laser and the conventional pump laser are optically combined by a polarization beam combiner (PBC).

[0045] The underwater device 100 adopts a single fiber pair 4x4 protection, and the underwater device 100 uses a 4x4 pump optical path. Figure 3 shows a structural schematic diagram 2 of the underwater device 100, and the implementation principle is similar, so the description is omitted.

[0046] Among them, the 4x8 pump laser used in the underwater device 100 is realized by a similar principle, so a description thereof will be omitted.

[0047] In some embodiments of the present application, the underwater device 100 forms a combined loopback path of the COTDR backscattered optical signal between the upstream and downstream optical fiber links of the same fiber pair. The paths are cross-connected by a first optical fiber coupler and a second optical fiber coupler, and pump light is input to the optical amplification unit. At the same time, each first-stage 2x2 optical fiber coupler combines pump light from two pump lasers and outputs two first-stage partial pump light beams. Each second-stage 2x2 optical fiber coupler combines two first-stage partial pump light beams from different first-stage 2x2 optical fiber couplers and outputs two second-stage partial pump light beams. Each second-stage partial pump light beam provides energy to one EDFA module. The pump laser output from each pump laser can provide 25% of the energy to one of four EDFA modules, and each EDFA module receives 25% of the pump laser energy from each of the four pump lasers. The first and second optical fiber couplers are cross-connected to form a complete closed loop, which has structural symmetry and can theoretically be extended infinitely. This allows the underwater equipment communication system to be applied to any fiber pair of three or more fiber pairs.

[0048] In some embodiments, one backup pump laser is provided for each of the conventional pump lasers. For example, as shown in FIG. 4, the underwater equipment 100 adopts a single fiber pair 2x2 protection, that is, the outputs of two conventional pump lasers are combined through an optical fiber coupler and then output to two optical amplification units of one fiber pair in a 50%:50% ratio, and the conventional pump laser and the backup pump laser are combined by a polarization beam combiner or an optical switch.

[0049] By disposing a backup pump laser for every normal pump laser of every underwater device 100 in the entire circuit, the space and granularity of the performance adjustment of the entire underwater device communication system can be improved.

[0050] In some embodiments, the optical device 130 is a polarization beam combiner or an optical switch. The backup pump laser 102 and the normal pump laser 101 can be optically combined by a polarization beam combiner (PBC), and the backup pump laser 102 and the normal pump laser 101 can be further controlled using an optical switch.

[0051] The backup pump laser 102 and the normal pump laser 101 are combined by a polarization beam combiner or strobed (selected to be on) via an optical switch, and the backup pump laser 102 is always closed and is turned on when needed, and the normal pump laser 101 and the backup pump laser 102 are operated together to make the pump output power meet the output requirement.

[0052] In some embodiments, the backup pump laser 102 can be selected to have the same output power and reliability level as the normally operating normal pump laser 101. The same type of device as the online operating pump can be selected to realize equivalent replacement in the case of pump failure.

[0053] The backup pump laser 102 is used only to compensate for the power loss due to aging, and in some embodiments, the backup pump laser 102 has the same reliability level as the normal pump laser 101 that is still operating normally, but has a lower output power, and is of a type that has a lower output power than the normal pump laser operating online, thereby reducing costs.

[0054] The backup pump laser 102 is activated in the middle or later stages of the system, so its cumulative operating time is not long and its reliability requirements are not high. In some embodiments, the backup pump laser 102 has a lower reliability requirement than the normal pump laser 101, which is still operating properly. For example, a land-grade pump that is not used in submarine cable repeaters can be selected, thereby reducing costs. Furthermore, because device failure is a probabilistic event, the possibility of some device failures can be probabilistically compensated for by deploying multiple devices with normal reliability levels.

[0055] It should be noted that if the working current of the pump laser is too large, the probability of the pump laser failing increases, so it is necessary to control the driving current of the backup pump laser 102. In some embodiments, based on theoretical analysis or actual measurement results of the optimal performance point of the entire undersea cable communication system, some of the backup pump lasers 102 of the underwater equipment 100 can be selectively turned on, where the working current of each backup pump laser 102 is kept constant.

[0056] In some embodiments, the driving current of the turned-on backup pump laser 102 can be adjusted based on theoretical analysis or actual measurement results of the optimal performance point of the entire undersea cable communication system, thereby ensuring that the underwater equipment 100 operates at the optimum performance state.

[0057] In addition, the underwater equipment 100 in the embodiments of the present application may be an optical repeater (RPT) or other equipment. During long-distance communication transmission, signals are lost in the cable, so optical repeaters (RPTs) with signal repeater and amplification functions are installed on the undersea cable at regular intervals, such as 50 km, 70 km, or 100 km, to enable long-distance signal transmission. During the construction of an underwater communication system, the underwater equipment 100 is usually installed directly on the cable, wound around it, and then thrown into the water together with the cable.

[0058] A backup pump laser 102 is added to the optical repeater to compensate for the reduced output power caused by the aging of the normal pump laser, and improve the aging condition of the pump laser, thereby making the output power of the optical repeater meet the operating requirements, maintaining a stable noise coefficient of the optical repeater, and maintaining stable transmission performance.

[0059] As shown in FIG. 5 , some embodiments of the present application further provide an underwater device communication system, which includes the underwater device 100 of the above embodiment, and the underwater device communication system includes: a first station 200 used to transmit a first data optical signal to the underwater device 100 via the first optical fiber 110; a second station 300 used to transmit a second data optical signal to the underwater device 100 via the second optical fiber 120; After receiving the first data optical signal, the underwater device 100 and amplifying the second data optical signal and outputting it to the second station 300, and receiving the second data optical signal and amplifying the second data optical signal and outputting it to the first station 200.

[0060] In some embodiments, the first station 200 is further used to transmit a detection optical signal to the underwater equipment 100 via the first optical fiber 110, and the underwater equipment 100 receives a first reflected optical signal from the optical fiber coupler 140 and transmits the first reflected optical signal toward the first station, where the first reflected optical signal is obtained after the amplified detection optical signal undergoes back-scattering Rayleigh scattering, and the first station 200 is further used to receive the first reflected optical signal and determine whether the conventional pump laser 101 has failed or deteriorated based on the first reflected optical signal.

[0061] In addition, the optical amplification unit has an output saturation effect characteristic, and when the input optical power of the amplifier reaches a threshold, the input optical power increases or decreases within a certain range, while the output optical power remains essentially unchanged, and the corresponding amplifier gain decreases or increases by essentially the same amount as the change in the input optical power. Based on the change in the scattered optical power of the optical repeater, it can be determined whether the normal pump laser has failed or deteriorated, and the backup pump laser can be easily started in a timely manner to compensate for the reduced output power caused by the deterioration of the normal pump laser.

[0062] As can be seen from the above technical solutions, some embodiments of the present application provide an underwater equipment and a communication system, the underwater equipment including a first optical fiber, a second optical fiber, a conventional pump laser, and at least one backup pump laser, the conventional pump laser is used to provide pump light to a first optical amplification unit located in the first optical fiber and a second optical amplification unit located in the second optical fiber, the conventional pump laser and the backup pump laser are respectively connected to input ports of an optical device of the first optical fiber and / or the second optical fiber, the optical device is used to optically couple the conventional pump laser and the backup pump laser, the backup pump laser is used to compensate for the output power of the conventional pump laser when the output power is lower than a target output power, the compensated output power is the output power lost by the conventional pump laser in an aging state, the backup pump laser is configured to be in an off state before a first command is received, and to be activated to output pump light when the first command is received, the first command being a control command sent when the output power of the conventional pump laser is lower than a target output power. The present application provides a method for installing at least one backup pump laser in underwater equipment, so that when the normal pump laser becomes obsolete, the backup pump laser can be activated to compensate for the pump output power of the underwater equipment, thereby improving the service life of submarine cable optical fiber communications.

[0063] Similar parts between the examples provided in this application may be referred to mutually, and the specific embodiments provided above are merely examples in the overall concept of this application and do not limit the scope of protection of this application. Any other embodiments extended based on the solutions of this application without the need for creative efforts by those skilled in the art will fall within the scope of protection of this application. [Explanation of symbols]

[0064] 100 - underwater equipment, 101 - normal pump laser, 102 - backup pump laser, 110 - first optical fiber, 120 - second optical fiber, 130 - optical device, 140 - optical fiber coupler, 150 - first optical amplification unit, 160 - second optical amplification unit, 200 - first station, 300 - second station.

Claims

1. a first optical fiber, a second optical fiber, a conventional pump laser, and at least one backup pump laser; the conventional pump laser is used to provide pump light to a first optical amplification unit located in the first optical fiber and a second optical amplification unit located in the second optical fiber; The normal pump laser and the backup pump laser are respectively connected to input ports of an optical device of the first optical fiber and / or the second optical fiber, wherein the optical device is used to optically couple the normal pump laser and the backup pump laser; The backup pump laser is used to compensate for the output power of the normal pump laser when the output power of the normal pump laser is smaller than the target output power, and the compensated output power is the output power lost when the normal pump laser is in an aging state; The backup pump laser is configured to be in an off state before a first command is received, and to be activated to output pump light when a first command is received, wherein the first command is a control command sent when an output power of the normal pump laser is lower than a target output power; The underwater equipment is further characterized in that the backup pump laser is in an off state before a second command is received, and is activated to output pump light when a second command is received, wherein the second command is a control command that is sent when the deterioration value of the underwater equipment is greater than a threshold value.

2. the conventional pump laser includes a first pump laser and a second pump laser connected to the backup pump laser; an input port of a first fiber optic coupler of the first optical fiber is connected to the first pump laser, and an output port of the first fiber optic coupler of the first optical fiber is connected to the first optical amplification unit; a second pump laser and the backup pump laser are respectively connected to input ports of the second optical fiber optical device, and an output port of the second optical fiber optical device is connected to the second optical amplification unit; The first pump laser is coupled to the first optical amplifier unit located in a first optical fiber.

2. The underwater equipment of claim 1, wherein the second pump laser is used to provide pump light to the second optical amplification unit located in the second optical fiber, and the second pump laser is used to provide pump light to the second optical amplification unit located in the second optical fiber.

3. the underwater equipment includes at least two first pump lasers and two second pump lasers, each of the first pump lasers providing 50% of the energy to the first optical amplification unit and each of the second pump lasers providing 50% of the energy to the second optical amplification unit; Alternatively, the underwater equipment of claim 2 includes at least four first pump lasers and four second pump lasers, each of the first pump lasers providing 25% of the energy to the first optical amplification unit, and each of the second pump lasers providing 25% of the energy to the second optical amplification unit.

4. 4. The underwater device according to claim 3, wherein the backup pump laser is connected to only one of the second pump lasers of the underwater device.

5. 3. The underwater device according to claim 2, wherein the first optical fiber and the second optical fiber belong to the same optical fiber pair, or the first optical fiber and the second optical fiber belong to different optical fiber pairs.

6. 2. The underwater equipment according to claim 1, wherein the optical device is a polarization beam combiner or an optical switch.

7. 2. The underwater equipment according to claim 1, wherein one backup pump laser is arranged for each of the normal pump lasers, and the normal pump laser and the backup pump laser are combined by a polarization beam combiner or an optical switch.

8. 2. The underwater device according to claim 1, wherein the underwater device is an optical repeater.

9. The underwater device according to any one of claims 1 to 8, a first station used to transmit a first data optical signal to the underwater device via the first optical fiber; a second station used to transmit a second data optical signal to the underwater device via the second optical fiber; an underwater equipment communication system, characterized in that the underwater equipment is used to receive the first data optical signal, amplify the first data optical signal, and then output it to the second station, and is used to receive the second data optical signal, amplify the second data optical signal, and then output it to the first station.

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