An ultra-wideband raman amplifier and control method for eliminating the gain impact of an osc signal

Abstract

The application relates to the field of optical communication technology and provides an ultra-wideband Raman amplifier capable of eliminating the influence of an OSC signal on gain and a control method. Before the OSC detection optical signal is coupled with the pump optical signals of the n pump lasers, the OSC detection optical signal is also coupled with a first optical splitter, and the detected OSC detection optical signal intensity is transmitted to a control unit through a first detector on the output side of the first optical splitter, so that the control unit adjusts the optical power of one or more pump lasers consistent with or similar to the OSC detection optical signal frequency band among the n pump lasers controlled by the control unit according to the OSC detection optical signal intensity. The application can eliminate the influence of the power of the monitoring channel OSC on the gain control precision, reduce the power of the longest wavelength pump laser itself, reduce power consumption, and improve the gain control precision of the overall system.

Description

[Technical Field]

[0001] This invention relates to the field of optical communication technology, and in particular to an ultra-wideband Raman amplifier and control method for eliminating the influence of OSC signals on gain. [Background Technology]

[0002] With the rapid evolution of new telecommunications services such as 5G, video-on-demand, virtual reality (VR), mobile IoT, and DCI data communication, the demand for bandwidth in backbone transmission networks is increasing. Compared to the traditional C-band (1528–1568 nm, a total of 40 nm) transmission bandwidth, C++ and L++ ultra-wideband Raman fiber amplifiers cover an ultra-large bandwidth of 1524–1627 nm, a total of 103 nm. In transmission systems, to monitor the operating status of equipment, an optical monitoring channel (OSC) is needed. According to international standards such as ITU-T, the wavelength of the OSC is in the range of 1510 ± 10 nm. To reduce costs, equipment manufacturers often do not use TEC control for the OSC's transmission module, as long as the wavelength does not exceed 1500 nm or 1520 nm. However, to cover the entire C++L++ ultra-wideband communication system, the longest pump wavelength of the Raman fiber amplifier is greater than 1510 nm, and the shortest pump wavelength is around 1420 nm. For C++L++ ultra-wideband communication systems, if the OSC still uses a traditional 1510nm laser without TEC (Transmission Controlled Laser), the wavelength of the OSC will vary with temperature around 1510nm due to the lack of TEC control. When the pump wavelength coincides with the OSC wavelength, the OSC signal cannot be demultiplexed and error detection cannot be performed. Therefore, the OSC laser chip must be controlled by TEC to allow the wavelength to vary within ±1nm. To reduce the isolation between the pump wavelength and the OSC wavelength, the OSC wavelength must deviate from the pump wavelength by more than 2-4nm. The shortest and longest wavelengths of the Raman-pumped laser will be more than 90nm apart, resulting in very strong interaction between the pumps. To achieve gain flatness across the entire wavelength range, the power ratio between each wavelength will be very complex. Since the longest pump wavelength is near the peak of the shortest wavelength amplification (13.2THz), even small power changes in the longest pump wavelength and nearby wavelengths will have a significant impact on the gain. Since the OSC wavelength is not inside the Raman pump module, but in actual engineering applications, the OSC wavelength will be transmitted in the optical fiber along with the pump wavelength and the signal wavelength. When the Raman gain is relatively large, the power of the OSC wavelength will greatly affect the calibrated Raman gain.

[0003] Therefore, overcoming the shortcomings of the existing technology is an urgent problem to be solved in this technical field. [Summary of the Invention]

[0004] The technical problem this invention aims to solve is that, since the OSC wavelength is not inside the Raman pump module, but in actual engineering applications, the OSC wavelength is transmitted in the optical fiber along with the pump wavelength and the signal wavelength. When the Raman gain is relatively large, the power of the OSC wavelength will greatly affect the calibrated Raman gain.

[0005] The present invention adopts the following technical solution:

[0006] An ultrawideband Raman amplifier and its control method for eliminating the influence of OSC signal on gain.

[0007] In a first aspect, the present invention provides an ultra-wideband Raman amplifier that eliminates the influence of OSC signals on gain, comprising:

[0008] n pump lasers connected sequentially through multiple multiplexers constitute an ultra-wideband pump optical signal source; each pump laser emits pump laser light in the band it covers.

[0009] The OSC signal receiving port couples the OSC detection optical signal it acquires with the pump optical signals of the n pump lasers through the first multiplexer. The coupled pump optical signal is then coupled to the transmission optical path through the second multiplexer to complete the pump amplification of the data optical signal and the channel monitoring of the transmission optical path by the OSC detection optical signal.

[0010] Before being coupled with the pump signals of the n pump lasers, the OSC detection optical signal is coupled with a first beam splitter. The intensity of the detected OSC detection optical signal is transmitted to the control unit through a first detector on the output side of the first beam splitter. The control unit then adjusts the optical power of one or more of the n pump lasers under its control based on the intensity of the OSC detection optical signal, using the frequency band of the OSC detection optical signal.

[0011] Preferably, n pump lasers connected sequentially through multiple multiplexers constitute an ultra-wideband pump source, specifically including:

[0012] Each pump laser has its own pump branch optical path, as well as a common pump main optical path;

[0013] Each pump branch optical path couples its pump optical signal to the main pump optical path through a general multiplexer, so that the integrated pump optical signal can be transmitted to the transmission optical path through the second multiplexer connected to the main pump optical path; or, each pump branch optical path couples its pump light to the main pump optical path through its own multiplexer in a serial or parallel coupling manner.

[0014] Preferably, the OSC signal receiving port couples its acquired detection optical signal with the pump optical signals of the n pump lasers through a first multiplexer, specifically including:

[0015] Obtain the center wavelength of the corresponding OSC signal, and determine one or two target pump lasers among the n pump lasers whose corresponding pump light signal is closest to the center wavelength of the OSC signal based on the center wavelength of the OSC signal;

[0016] A first multiplexer is provided in the pump optical path of one or two target pump lasers, and the OSC signal receiving port is coupled to one of the input ports of the first multiplexer; wherein, the other input port of the first multiplexer is coupled to the pump optical path of the corresponding target pump laser.

[0017] In a second aspect, the present invention provides a control method for an ultra-wideband Raman amplifier that eliminates the influence of OSC signals on gain, using the ultra-wideband Raman amplifier for eliminating the influence of OSC signals on gain as described in the first aspect, the method comprising:

[0018] The control unit adjusts the operating power of the n pump lasers according to the light intensity of the amplified data light signal to be achieved by the transmission optical path;

[0019] After the operating power of the n pump lasers is adjusted, the OSC detection optical signal is input;

[0020] When the control unit obtains the OSC detection optical signal power from the first detector, it triggers the adjustment of the optical power of one or more of the n pump lasers under its control that are in the same or similar frequency band as the OSC detection optical signal, so that the amplification intensity of the corresponding data optical signal remains consistent.

[0021] Preferably, the method is characterized in that, when adjusting the optical power of one or more pump lasers among the n pump lasers controlled by the calibration, which are in the same or similar frequency band as the OSC detection optical signal, the method confirms that the pump laser being calibrated and adjusted is the pump laser with the longest wavelength among the n pump lasers. The specific method includes:

[0022] The power of the longest wavelength pump laser is denoted as P. pump-final The wavelength is denoted as λ. pump-final The power of the optical signal detected by the OSC is denoted as P. osc-1 P osc-2 ...P osc-n The wavelength of the optical signal detected by OSC is denoted as λ. osc , including: λ osc-1 , λ osc-2 ……λ osc-n, n≥1; set the proportionality coefficient of the OSC detection optical signal power to be equivalent to the longest wavelength pump power, denoted as K. effective The wavelength of the optical signal detected by the OSC is Δλ = λ, which is the wavelength interval between the longest wavelength pump laser and the wavelength of the optical signal. pump-final -λ osc ;

[0023] The equivalent coefficients can be linearly fitted to the wavelength interval, expressed as: K effective = k×Δλ+b;

[0024] In practical Raman amplifier gain control, the pump power required for the longest wavelength is denoted as P. pump-final-contolling Then P pump-final-contolling =K effective-1 ×P osc-1 +K effective-2 ×P osc-2 +……+K effective-n ×P osc-n In real-time conditions, if the corresponding OSC detects optical signal λ osc-i If the wavelength does not exist, then the parameter P in the corresponding formula... osc-i The value is 0, and i is a parameter value between 1 and n.

[0025] Preferably, the control unit, based on the desired light intensity of the amplified data optical signal to be achieved by the transmission optical path, specifically includes:

[0026] By establishing the relationship between out-of-band ASE and gain, the relationship is as follows:

[0027] Out-of-band ASE = K × Gain + b + pointloss; the gain is controlled by controlling the power of the out-of-band ASE; where K is the linear relationship constant between the two, b is the influencing parameter, and pointloss is the connection loss between the pump laser and the fiber.

[0028] Thirdly, the present invention also provides a control method for an ultra-wideband Raman amplifier that eliminates the influence of OSC signals on gain, the method comprising:

[0029] n pump lasers connected sequentially through multiple multiplexers constitute an ultra-wideband pump optical signal source; each pump laser emits pump laser light in the band it covers.

[0030] The OSC signal receiving port couples the OSC detection optical signal it acquires with the pump optical signals of the n pump lasers through the first multiplexer. The coupled pump optical signal is then coupled to the transmission optical path through the second multiplexer to complete the pump amplification of the data optical signal and the channel monitoring of the transmission optical path by the OSC detection optical signal.

[0031] The control unit controls the corresponding n pump lasers to be in a stopped state, thereby multiplexing the pump total power detection photodetector located on the pump main optical path to complete the detection of the OSC detection light signal intensity;

[0032] The control unit adjusts the optical power of one or more of the n pump lasers under its control, based on the intensity of the OSC-detected optical signal, to be consistent with or close to the frequency band of the OSC-detected optical signal.

[0033] Preferably, the control unit controls the corresponding n pump lasers to be in a stopped state, specifically including:

[0034] Before the n-pump laser is started and put into operation, the control unit collects the output of the total pump power detection photodetector in real time. If a valid detection result is obtained, it is recorded as the power intensity of the OSC detection optical signal.

[0035] If no valid detection result is obtained, a request signal is sent to the OSC detection optical signal transmitter so that the optical power detection of the OSC detection optical signal can be completed before the activated n-pump laser enters the working state.

[0036] Preferably, when adjusting the optical power of one or more pump lasers among the n pump lasers under its control that have the same or similar frequency band as the OSC detection optical signal, it is confirmed that the pump laser being calibrated and adjusted is the pump laser with the longest wavelength among the n pump lasers. The method specifically includes:

[0037] The power of the longest wavelength pump laser is denoted as P. pump-final The wavelength is denoted as λ. pump-final The power of the optical signal detected by the OSC is denoted as P. osc-1 P osc-2 ...P osc-n The wavelength of the optical signal detected by OSC is denoted as λ. osc , including: λ osc-1、 λ osc-2 ……λ osc-n , n≥1; set the proportionality coefficient of the OSC detection optical signal power to be equivalent to the longest wavelength pump power, denoted as K. effective The wavelength of the optical signal detected by the OSC is Δλ = λ, which is the wavelength interval between the longest wavelength pump laser and the wavelength of the optical signal. pump-final -λ osc ;

[0038] The equivalent coefficients can be linearly fitted to the wavelength interval, expressed as: K effective = k×Δλ+b;

[0039] In practical Raman amplifier gain control, the pump power required for the longest wavelength is denoted as P. pump-final-contolling Then P pump-final-contolling =K effective-1 ×P osc-1 +K effective-2 ×P osc-2 +……+K effective-n ×P osc-n In real-time conditions, if the corresponding OSC detects optical signal λ osc-i If the wavelength does not exist, then the parameter P in the corresponding formula... osc-i The value is 0, and i is a parameter value between 1 and n.

[0040] Preferably, the control unit, based on the desired light intensity of the amplified data optical signal to be achieved by the transmission optical path, specifically includes:

[0041] By establishing the relationship between out-of-band ASE and gain, the relationship is as follows:

[0042] Out-of-band ASE = K × Gain + b + pointloss; the gain is controlled by controlling the power of the out-of-band ASE; where K is the linear relationship constant between the two, b is the influencing parameter, and pointloss is the connection loss between the pump laser and the fiber.

[0043] Fourthly, the present invention also provides a control unit device for implementing the ultra-wideband Raman amplifier control method for eliminating the influence of OSC signals on gain as described in the second or third aspect, the device comprising:

[0044] At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor for performing the ultrawideband Raman amplifier control method for eliminating the influence of OSC signals on gain as described in the first aspect.

[0045] Fifthly, the present invention also provides a non-volatile computer storage medium storing computer-executable instructions, which are executed by one or more processors to perform the ultra-wideband Raman amplifier control method for eliminating the influence of OSC signals on gain as described in the second or third aspect.

[0046] This invention eliminates the impact of the monitoring channel (OSC) power on gain control accuracy by equating the power of the monitoring channel (OSC) transmitted in the transmission system with the power of the longest wavelength pump laser, thereby reducing the power of the longest wavelength pump laser itself, lowering power consumption, and improving the overall system gain control accuracy.

[0047] Through a special optical path design, this invention retains the OSC monitoring wavelength around 1510nm in ultra-wideband Raman amplifier applications, while also achieving a significant Raman gain for the OSC monitoring wavelength. This greatly enhances the transmission range of the OSC and improves transmission performance. [Attached Image Description]

[0048] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0049] Figure 1 This is a schematic diagram of an optical path structure for introducing an OSC channel into a conventional data transmission channel, provided by an embodiment of the present invention.

[0050] Figure 2 This is a schematic diagram of the optical path structure of an ultra-wideband C++L++ Raman fiber amplifier that eliminates the influence of OSC channel power, provided by an embodiment of the present invention.

[0051] Figure 3 This is a schematic diagram of an optical path structure provided by an embodiment of the present invention, which draws on the method of introducing an OSC channel in existing conventional data transmission channels and is applicable to ultra-wideband Raman amplification.

[0052] Figure 4 This is a serial connection method between pump lasers provided in an embodiment of the present invention;

[0053] Figure 5 This is a parallel connection method between pump lasers provided in an embodiment of the present invention;

[0054] Figure 6 This is a schematic flowchart of a control method for an ultrawideband Raman amplifier that eliminates the influence of OSC signal on gain, provided by an embodiment of the present invention.

[0055] Figure 7 This is a schematic diagram of another ultra-wideband C++L++ Raman fiber amplifier optical path structure for eliminating the influence of OSC channel power, provided by an embodiment of the present invention.

[0056] Figure 8 This is a schematic flowchart of another control method for an ultra-wideband Raman amplifier to eliminate the influence of OSC signal on gain provided by an embodiment of the present invention;

[0057] Figure 9 This is a schematic diagram of another ultra-wideband C++L++ Raman fiber amplifier optical path structure for eliminating the influence of OSC channel power, provided by an embodiment of the present invention.

[0058] Figure 10 This is the naming method for the three ports of WDM provided in this embodiment of the invention;

[0059] Figure 11 This is a schematic diagram of the wavelength characteristics of a bandpass three-port WDM provided in an embodiment of the present invention;

[0060] Figure 12 This is a schematic diagram of the wavelength characteristics of a high-pass and low-pass three-port device provided in an embodiment of the present invention;

[0061] Figure 13 This is a schematic diagram illustrating the effect of OSC channel power on the gain of an ultra-wideband Raman amplifier, provided in an embodiment of the present invention.

[0062] Figure 14 This is a schematic diagram of the gain control effect after the OSC channel power is equivalent to the longest wavelength pump power, provided by an embodiment of the present invention.

[0063] Figure 15 This is a schematic diagram of a control unit device provided in an embodiment of the present invention.

Detailed Implementation Methods

[0064] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 merely illustrative and not intended to limit the invention.

[0065] In the description of this invention, the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and do not require that this invention must be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0066] For the OSC channel in an optical communication system, an uncooled laser of 1510±6.5nm is generally used to detect the optical signal. The output power is generally ≤5mW, i.e. 7dBm. For Raman amplifiers with a gain of less than 14dB, this power level has little impact on the Raman gain. However, for the high-gain ultrawideband Raman fiber amplifier involved in this invention (such as a bandwidth exceeding 46nm, or even reaching 100nm), this power level will have a significant impact on the Raman gain.

[0067] This invention integrates an OSC demultiplexer within an ultra-wideband Raman pump module, and redirects the OSC channel (such as...) that was originally directly fed into the data transmission optical path... Figure 1As shown in the diagram, the OSC detection principle architecture is adjusted to the pump main optical path (in this embodiment, it may also be adjusted to the pump branch optical path, which is also a feasible implementation method). The power of the OSC detection optical signal in the same direction as the pump is monitored. During normal operation, the power of the OSC wavelength is equivalent to the power of the closest Raman pump wavelength according to a certain ratio, thus eliminating the Raman gain effect caused by the OSC. In the current ultra-wideband C++L++ (1524~1627nm) communication system, the frequency interval between the shortest Raman pump wavelength (e.g., 1420nm) and the 1510nm OSC channel will be greater than 12THz, which basically reaches the maximum Raman gain frequency shift of 13.2THz. Moreover, the OSC is very likely already within the pump wavelength range. Therefore, in the preferred embodiment of this invention, the OSC channel wavelength needs to be precisely controlled by TEC, and the wavelength variation range does not exceed ±1nm. Since the OSC detection optical signal needs to be bit error detected, the pump wavelength and the OSC wavelength should be at least ±1nm apart.

[0068] In a specific implementation of this invention, the Raman amplifier gain control is achieved using a feedforward + feedback approach. The feedforward method involves pre-calibrating to determine the power of each pump wavelength corresponding to different gains in a certain type of optical fiber. Then, a table is created in advance showing the values ​​corresponding to the gain and pump power, and stored in an EEPROM. When the amplifier is in operation, the corresponding power is looked up based on the set gain. Alternatively, instead of looking up the table, each pump power is linearly or polynomially fitted to the gain (no more than a third term).

[0069] Next, through specific embodiments, the core points of the present invention described above will be integrated and demonstrated in the form of technical solutions. Furthermore, 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.

[0070] Example 1:

[0071] Embodiment 1 of this invention provides an ultra-wideband Raman amplifier that eliminates the influence of OSC signals on gain, referencing... Figure 2 As shown, it includes:

[0072] n pump lasers connected sequentially through multiple multiplexers constitute an ultra-wideband pump optical signal source; each pump laser emits pump laser light in the band it covers.

[0073] For example Figure 2 The multiple combiners are represented by WDM1, WDM2, and related combiners (not shown by ellipses) between pump lasers 4 to n-1 in the diagram. Figure 2In the example, pump laser 1 and pump laser 2 outputs are directly combined into the optical path connected to WDM1. This is actually considering the real-world scenario where pump laser 1 and pump laser 2 might be fabricated inside an optical module, and their direct connection can be understood as optical path coupling within the optical module.

[0074] The OSC signal receiving port is connected to the first combiner ( Figure 2 An exemplary embodiment is that the WDM3) couples its acquired OSC detection optical signal with the pump optical signals of the n pump lasers. The coupled pump optical signal is then coupled to the data transmission optical path via a second combiner, completing the pump amplification of the data optical signal and the channel monitoring of the transmission optical path by the OSC detection optical signal. To more clearly illustrate the implementation of the technical solution of this invention... Figure 2 The structure, and the existing structural differences without incorporating the optical path structure of this invention, are also referenced in the embodiments of this invention. Figure 1 Based on this, the optical path diagram of a possible ultra-wideband Raman amplifier under existing technological conditions is typically presented, such as... Figure 3 As shown, this does not mean that... Figure 3 It is existing technology, but the applicant's... Figure 2 As a reference to existing technologies, the optical path diagram is presented based on the conventional thinking logic of those skilled in the art.

[0075] Before being coupled with the pump signals of the n pump lasers, the OSC detection optical signal is also coupled with the first beam splitter (e.g., Figure 2 As shown in 118), and through the first detector on the output port side of the first beam splitter (e.g. Figure 2 As shown in Figure 115-5, the detected OSC detection light signal intensity is transmitted to the control unit (e.g., Figure 2 As shown in Figure 101), the control unit adjusts the optical power of one or more of the n pump lasers under its control that are in the same or similar frequency band as the OSC detection optical signal based on the intensity of the OSC detection optical signal.

[0076] This invention eliminates the impact of the OSC power on gain control accuracy by equating the power of the monitoring channel, which is transmitted together with the Raman pump laser in the transmission system, to the longest wavelength pump power. This reduces the power of the longest wavelength pump laser itself, lowers power consumption, and improves the overall system gain control accuracy.

[0077] Through a special optical path design, this invention retains the OSC monitoring wavelength (i.e., the OSC detection optical signal mentioned above) around 1510nm in ultra-wideband Raman amplifier applications. At the same time, the OSC monitoring wavelength also achieves a large Raman gain, which greatly improves the transmission range of OSC and enhances its transmission performance.

[0078] In this embodiment of the invention, the n pump lasers sequentially connected through multiple multiplexers in the above-mentioned pump amplifier constitute an ultra-wideband pump source, and specific implementation methods are also provided, including:

[0079] Each pump laser has its own pump branch optical path (e.g.) Figure 2 The paths between WDM1 and pump lasers 1 and 2, and between WDM2 and pump lasers n-1 and n (which can be understood as pump branch paths), and a common main pump path (e.g.) Figure 2 The connection between WDM1 and WDM4 can be understood as the pump main optical path.

[0080] Each pump branch optical path couples its pump optical signal to the main pump optical path via a common multiplexer (i.e., using Arrayed Waveguide Grating (AWG) technology). The combined pump optical signal is then transmitted to the transmission optical path via a second multiplexer connected to the main pump optical path. Figure 2 different, Figure 2 The diagram illustrates that each pump laser has its own independent combiner; or, each pump branch optical path passes through its own combiner, such as... Figure 4 As shown, in a serial coupling manner (relatively speaking, Figure 2 This is the method used, or as... Figure 5 As shown, parallel coupling couples the respective pump beams to the main pump optical path. Among these methods, there are advantages and disadvantages in terms of cost and performance; the specific method chosen depends on the specific product planning requirements.

[0081] In this embodiment of the invention, the OSC signal receiving port couples its acquired detection optical signal with the pump optical signals of the n pump lasers through a first multiplexer, specifically including:

[0082] Obtain the center wavelength of the corresponding OSC signal, and determine one or two target pump lasers among the n pump lasers whose corresponding pump light signal is closest to the center wavelength of the OSC signal based on the center wavelength of the OSC signal;

[0083] A first multiplexer is provided in the pump optical path of one or two target pump lasers, and the OSC signal receiving port is coupled to one of the input ports of the first multiplexer; wherein, the other input port of the first multiplexer is coupled to the pump optical path of the corresponding target pump laser.

[0084] In this embodiment of the invention, for OSC channel OSC detection optical signal power detection, if the specific OSC wavelength is known in advance, no narrowband filter is needed before the photodetector; only a beam splitter and photodetector are required. To accommodate different customers' OSC wavelengths, the OSC beam can be further split into multiple paths after splitting. When each path enters the photodetector for power detection, one or more narrowband filters of different wavelengths are first added. In actual operation, the equivalent power scaling factor is determined based on the wavelength interval between a specific detection wavelength and the longest wavelength pump laser.

[0085] Example 2:

[0086] This invention provides a control method for an ultra-wideband Raman amplifier that eliminates the influence of OSC signals on gain, using the ultra-wideband Raman amplifier for eliminating the influence of OSC signals on gain as described in Example 1. Figure 6 As shown, the method includes:

[0087] In step 201, the control unit adjusts the operating power of the n pump lasers according to the light intensity of the amplified data light signal to be achieved by the transmission optical path.

[0088] In step 202, after the operating power of the n pump lasers is adjusted, the OSC detection optical signal is input.

[0089] In step 203, when the control unit obtains the OSC detection optical signal power from the first detector, it triggers the adjustment of the optical power of one or more of the n pump lasers under its control that are consistent with or close to the frequency band of the OSC detection optical signal, so that the amplification intensity of the corresponding data optical signal remains consistent.

[0090] This invention eliminates the impact of the OSC power on gain control accuracy by equating the power of the monitoring channel, which is transmitted together with the Raman pump laser in the transmission system, to the longest wavelength pump power. This reduces the power of the longest wavelength pump laser itself, lowers power consumption, and improves the overall system gain control accuracy.

[0091] Through a special optical path design, this invention retains the OSC monitoring wavelength (i.e., the OSC detection optical signal mentioned above) around 1510nm in ultra-wideband Raman amplifier applications. At the same time, the OSC monitoring wavelength also achieves a large Raman gain, which greatly improves the transmission range of OSC and enhances its transmission performance.

[0092] In this embodiment of the invention, when adjusting the optical power of one or more pump lasers among the n pump lasers under its control that have the same or similar frequency band as the OSC detection optical signal, it is confirmed that the pump laser being calibrated and adjusted is the pump laser with the longest wavelength among the n pump lasers. The method specifically includes:

[0093] The power of the longest wavelength pump laser is denoted as P. pump-final The wavelength is denoted as λ. pump-final The power of the optical signal detected by the OSC is denoted as P. osc-1 P osc-2 ...P osc-n The wavelength of the optical signal detected by OSC is denoted as λ. osc , including: λ osc-1 , λ osc-2 ……λ osc-n , n≥1; set the proportionality coefficient of the OSC detection optical signal power to be equivalent to the longest wavelength pump power, denoted as K. effective The wavelength of the optical signal detected by the OSC is Δλ = λ, which is the wavelength interval between the longest wavelength pump laser and the wavelength of the optical signal. pump-final -λ osc ;

[0094] The equivalent coefficients can be linearly fitted to the wavelength interval, expressed as: K effective = k×Δλ+b;

[0095] In practical Raman amplifier gain control, the pump power required for the longest wavelength is denoted as P. pump-final-contolling Then P pump-final-contolling =K effective-1 ×P osc-1 +K effective-2 ×P osc-2 +……+K effective-n ×P osc-n In real-time conditions, if the corresponding OSC detects optical signal λ osc-i If the wavelength does not exist, then the parameter P in the corresponding formula... osc-i The value is 0, and i is a parameter value between 1 and n.

[0096] On the other hand, the control unit, based on the light intensity of the amplified data light signal to be achieved by the transmission optical path, specifically includes:

[0097] By establishing the relationship between out-of-band ASE and gain, the relationship is as follows:

[0098] Out-of-band ASE = K × Gain + b + pointloss; the gain is controlled by controlling the power of the out-of-band ASE; where K is the linear relationship constant between the two, b is the influencing parameter, and pointloss is the connection loss between the pump laser and the fiber.

[0099] This invention eliminates the impact of OSC power on gain control accuracy by equating the power of the monitoring channel, which is transmitted in the transmission system along with the Raman pump laser, to the longest wavelength pump power. This reduces the power of the longest wavelength pump laser itself, lowers power consumption, and improves the overall system gain control accuracy. Through a special optical path design, the OSC monitoring wavelength near 1510nm is retained, while a significant Raman gain is achieved at the OSC monitoring wavelength. This greatly increases the OSC transmission range and results in superior transmission performance.

[0100] Example 3:

[0101] This invention also provides a control method for an ultra-wideband Raman amplifier that eliminates the influence of OSC signals on gain. Unlike the amplifier structure of Embodiment 1 and the corresponding control method in Embodiment 2, this invention proposes a control method that avoids the first beam splitter and first detector used in Embodiment 1, thus further reducing the cost of implementation while partially increasing control complexity. Before implementation, the corresponding structure should be implemented similarly to Embodiment 1, such as... Figure 7 As shown, n pump lasers connected sequentially via multiple multiplexers constitute an ultra-wideband pump optical signal source; each pump laser emits pump laser light within its covered wavelength band; the OSC signal receiving port couples its acquired OSC detection optical signal with the pump optical signals of the n pump lasers via a first multiplexer, and the coupled pump optical signal is then coupled to the transmission optical path via a second multiplexer, completing the pump amplification of the data optical signal and the channel monitoring of the transmission optical path by the OSC detection optical signal; as shown... Figure 8 As shown, the method includes:

[0102] In step 301, the control unit controls the corresponding n pump lasers to be in a stopped working state, thereby multiplexing the pump total power detection photodetector located on the pump main optical path to complete the detection of the OSC detection light signal intensity.

[0103] In step 302, the control unit adjusts the optical power of one or more of the n pump lasers under its control that are in the same or similar frequency band as the OSC-detected optical signal, based on the intensity of the OSC-detected optical signal.

[0104] This invention eliminates the impact of the OSC power on gain control accuracy by equating the power of the monitoring channel, which is transmitted together with the Raman pump laser in the transmission system, to the longest wavelength pump power. This reduces the power of the longest wavelength pump laser itself, lowers power consumption, and improves the overall system gain control accuracy.

[0105] Through a special optical path design, this invention retains the OSC monitoring wavelength (i.e., the OSC detection optical signal mentioned above) around 1510nm in ultra-wideband Raman amplifier applications. At the same time, the OSC monitoring wavelength also achieves a large Raman gain, which greatly improves the transmission range of OSC and enhances its transmission performance.

[0106] Regarding the control unit described above, which controls the corresponding n pump lasers to be in a stopped state, there is a relatively complete implementation scheme, specifically including:

[0107] Before the n-pump laser is started and put into operation, the control unit collects the output of the total pump power detection photodetector in real time. If a valid detection result is obtained, it is recorded as the power intensity of the OSC detection optical signal.

[0108] If no valid detection result is obtained, a request signal is sent to the OSC detection optical signal transmitter so that the optical power detection of the OSC detection optical signal can be completed before the activated n-pump laser enters the working state.

[0109] In this embodiment of the invention, as described in Embodiment 1, when adjusting the optical power of one or more pump lasers among the n pump lasers controlled by the system that are in the same or similar frequency band as the OSC detection optical signal, it is confirmed that the pump laser being calibrated and adjusted is the pump laser with the longest wavelength among the n pump lasers. The method specifically includes:

[0110] The power of the longest wavelength pump laser is denoted as P. pump-final The wavelength is denoted as λ. pump-final The power of the optical signal detected by the OSC is denoted as P. osc-1 P osc-2 ...P osc-n The wavelength of the optical signal detected by OSC is denoted as λ. osc , including: λ osc-1 , λ osc-2 ……λ osc-n, n≥1; set the proportionality coefficient of the OSC detection optical signal power to be equivalent to the longest wavelength pump power, denoted as K. effective The wavelength of the optical signal detected by the OSC is Δλ = λ, which is the wavelength interval between the longest wavelength pump laser and the wavelength of the optical signal. pump-final -λ osc ;

[0111] The equivalent coefficients can be linearly fitted to the wavelength interval, expressed as: K effective = k×Δλ+b;

[0112] In practical Raman amplifier gain control, the pump power required for the longest wavelength is denoted as P. pump-final-contolling Then P pump-final-contolling =K effective-1 ×P osc-1 +K effective-2 ×P osc-2 +……+K effective-n ×P osc-n In real-time conditions, if the corresponding OSC detects optical signal λ osc-i If the wavelength does not exist, then the parameter P in the corresponding formula... osc-i The value is 0, and i is a parameter value between 1 and n.

[0113] On the other hand, the control unit, based on the light intensity of the amplified data light signal to be achieved by the transmission optical path, specifically includes:

[0114] By establishing the relationship between out-of-band ASE and gain, the relationship is as follows:

[0115] Out-of-band ASE = K × Gain + b + pointloss; the gain is controlled by controlling the power of the out-of-band ASE; where K is the linear relationship constant between the two, b is the influencing parameter, and pointloss is the connection loss between the pump laser and the fiber.

[0116] Example 4:

[0117] The embodiments of the present invention focus on the structure described in Embodiment 1. Figure 2 The connection relationships and characteristics of the internal structural components are described, specifically regarding the solution used in Embodiment 1. Figure 2 The technical scenario is described in a relatively complete manner from the perspective of structural characteristics. It should not be understood here that the technical solution of Embodiment 1 is only applicable to... Figure 2 The structural scene.

[0118] Figure 2 The optical path structure of an ultra-wideband Raman fiber amplifier that eliminates the influence of OSC optical power on ultra-wideband Raman gain is shown. Figure 2An optical path structure for an ultra-wideband Raman amplifier with a fixed OSC detection optical signal was added to the pump band. This structure includes pump lasers 1 (102), 2 (103), 3 (104), 4 (105)...n-1 (106), n (107), pump depolarization combiners 108-1, 108-2...108-n with isolators, pump / pump combiner WDM1 (109), pump / pump combiner WDM2 (110), pump / OSC channel combiner WDM3 (111), bidirectional coupler (112), pump reflection photodetector (115-1), and pump total power detection photodetector. The detector (115-2) is a pump / pump combiner WDM4 (113), an out-of-band ASE filter WDM5 (114), and the transmission end of the out-of-band ASE filter WDM5 is the out-of-band light frequency component, which is directly connected to the photodetector (115-4). The reflection end of the out-of-band ASE filter WDM5 is the signal light frequency component. After being split by the coupler (116), the small end enters the photodetector (115-3), and the large end is used as the signal output. The OSC port receives the light from the external fixed wavelength OSC channel. The received OSC signal is first split by the coupler (118), and the small end enters the photodetector (115-5), while the large end enters the transmission end of the pump / OSC channel combiner WDM3 (111). Figure 2 117 in the diagram is an isolator, while the corresponding 119 is the transmission optical fiber for normal digital optical signals located upstream of the pump amplifier proposed in this invention.

[0119] Figure 9 In order to be in Figure 2 The OSC channel, derived from this, is specifically an example of multiple wavelengths. The OSC channel power simultaneously monitors the optical path structure, and the pump combiner and signal power are... Figure 2 They are basically the same, except that the OSC port receives light from the external fixed wavelength OSC channel. The received OSC signal is first split by the coupler (118), and then the small end enters the coupler (120) to be split into multiple optical paths. Before entering the PD, the split optical paths are all filtered by different wavelength narrowband filters, such as narrowband filter (121), narrowband filter (122), narrowband filter (123)... and then enter the photodetector (115-5), photodetector (115-6)... photodetector (115-n).

[0120] Figures 10-12 It shows Figure 2 and Figure 9The naming convention for the ports of a three-port WDM device is as follows: For the three-port WDM201, the common port is 201-1, the reflection port is 201-2, and the transmission port is 201-3. For a bandpass three-port WDM, if the wavelength range is between wavelength 2 and wavelength 3, that wavelength is a transmission port; the range between wavelength 1 and wavelength 2, or between wavelength 3 and wavelength 3, is a forbidden range; wavelengths shorter than wavelength 2 or longer than wavelength 3 are reflection ports. For high-pass and low-pass three-port WDMs, wavelengths shorter than 5 are either reflection or transmission ports; wavelengths between 5 and 6 are a forbidden range; wavelengths longer than 6 are either transmission or reflection ports. Figure 2 and Figure 9 Each WDM in the system can be selected as a bandpass three-port device or a high-pass / low-pass device, and can be designed according to the specific wavelength.

[0121] In this example, the gain of the low-gain ultra-wideband C++L++ Raman amplifier is 14dB, and the gain of the high-gain ultra-wideband C++L++ Raman amplifier is 25dB. This method primarily achieves precise gain control of the ultra-wideband Raman amplifier by proportionally equating the incoming OSC channel power to the power of the longest wavelength pump laser. Figure 13 The gain spectrum of the low-gain amplifier controlled by this method is shown, demonstrating the effect of 5mW external OSC optical power on the gain of a 14dB ultrawideband Raman amplifier. Figure 14 The gain spectrum of the high-gain Raman amplifier controlled by this method is shown, demonstrating the effect of 5mW external OSC optical power on the gain of the 25dB ultra-wideband Raman amplifier. The figure shows that the gain control effect achieved by the power equivalence method is quite ideal, and both methods can achieve the best gain flatness.

[0122] Example 5:

[0123] like Figure 15 The diagram shown is a schematic representation of the architecture of an ultra-wideband Raman amplifier control device for eliminating the influence of OSC signals on gain according to an embodiment of the present invention. The ultra-wideband Raman amplifier control device for eliminating the influence of OSC signals on gain in this embodiment includes one or more processors 21 and a memory 22. Figure 15 Take a processor 21 as an example.

[0124] Processor 21 and memory 22 can be connected via a bus or other means. Figure 15 Taking the example of a connection between China and Israel via a bus.

[0125] The memory 22, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs and non-volatile computer-executable programs, such as the ultra-wideband Raman amplifier control method for eliminating the influence of OSC signals on gain in Embodiment 1. The processor 21 executes the ultra-wideband Raman amplifier control method for eliminating the influence of OSC signals on gain by running the non-volatile software programs and instructions stored in the memory 22.

[0126] Memory 22 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 22 may optionally include memory remotely located relative to processor 21, which can be connected to processor 21 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0127] The program instructions / modules are stored in the memory 22. When executed by one or more processors 21, they perform the ultra-wideband Raman amplifier control method for eliminating the influence of the OSC signal on the gain described in Embodiment 1 above. For example, they perform the above-described... Figure 6 and Figure 8 The steps shown.

[0128] It is worth noting that the information interaction and execution process between the modules and units in the above-mentioned device and system are based on the same concept as the processing method embodiment of the present invention. For details, please refer to the description in the method embodiment of the present invention, and will not be repeated here.

[0129] Those skilled in the art will understand that all or part of the steps in the various methods of the embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, etc.

[0130] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An ultrawideband Raman amplifier that eliminates the influence of OSC signals on gain, characterized in that, include: n pump lasers connected sequentially through multiple multiplexers constitute an ultra-wideband pump optical signal source; each pump laser emits pump laser light in the band it covers. The OSC signal receiving port couples the OSC detection optical signal it acquires with the pump optical signals of the n pump lasers through the first multiplexer. The coupled pump optical signal is then coupled to the data transmission optical path through the second multiplexer to complete the pump amplification of the data optical signal and the channel monitoring of the transmission optical path by the OSC detection optical signal. Before being coupled with the pump signals of the n pump lasers, the OSC detection optical signal is coupled with a first beam splitter. The intensity of the detected OSC detection optical signal is transmitted to the control unit through a first detector on the output side of the first beam splitter. The control unit then adjusts the optical power of one or more of the n pump lasers under its control based on the intensity of the OSC detection optical signal, using the frequency band of the OSC detection optical signal.

2. The ultra-wideband Raman amplifier for eliminating the influence of OSC signal on gain according to claim 1, characterized in that, n pump lasers connected sequentially through multiple combiners constitute an ultrawideband pump source, specifically including: Each pump laser has its own pump branch optical path, as well as a common pump main optical path; Each pump branch optical path couples its pump optical signal to the main pump optical path through a general multiplexer, so that the integrated pump optical signal can be transmitted to the transmission optical path through the second multiplexer connected to the main pump optical path; or, each pump branch optical path couples its pump light to the main pump optical path through its own multiplexer in a serial or parallel coupling manner.

3. The ultra-wideband Raman amplifier for eliminating the influence of OSC signal on gain according to claim 1, characterized in that, The OSC signal receiving port couples its acquired detection optical signal with the pump optical signals of the n pump lasers through a first multiplexer, specifically including: Obtain the center wavelength of the corresponding OSC signal, and determine one or two target pump lasers among the n pump lasers whose corresponding pump light signal is closest to the center wavelength of the OSC signal based on the center wavelength of the OSC signal; A first multiplexer is provided in the pump optical path of one or two target pump lasers, and the OSC signal receiving port is coupled to one of the input ports of the first multiplexer; wherein, the other input port of the first multiplexer is coupled to the pump optical path of the corresponding target pump laser.

4. A control method for an ultra-wideband Raman amplifier that eliminates the influence of OSC signals on gain, characterized in that, The method of using an ultrawideband Raman amplifier for eliminating the influence of OSC signal on gain as described in any one of claims 1-3 includes: The control unit adjusts the operating power of the n pump lasers according to the light intensity of the amplified data light signal to be achieved by the transmission optical path; After the operating power of the n pump lasers is adjusted, the OSC detection optical signal is input; When the control unit obtains the OSC detection optical signal power from the first detector, it triggers the adjustment of the optical power of one or more of the n pump lasers under its control that are in the same or similar frequency band as the OSC detection optical signal, so that the amplification intensity of the corresponding data optical signal remains consistent.

5. The control method for eliminating the influence of OSC signal on gain of an ultrawideband Raman amplifier according to claim 4, characterized in that, When adjusting the optical power of one or more pump lasers among the n pump lasers under its control that have the same or similar frequency band as the OSC detection optical signal, it is confirmed that the pump laser being calibrated and adjusted is the pump laser with the longest wavelength among the n pump lasers. The specific method includes: The power of the longest wavelength pump laser is denoted as P. pump-final The wavelength is denoted as λ. pump-final The power of the optical signal detected by the OSC is denoted as P. osc-1 P osc-2 ...P osc-n The wavelength of the optical signal detected by OSC is denoted as λ. osc , including: λ osc-1、 λ osc-2 ……λ osc-n , n≥1; set the proportionality coefficient of the OSC detection optical signal power to be equivalent to the longest wavelength pump power, denoted as K. effective The wavelength of the optical signal detected by the OSC is Δλ = λ, which is the wavelength interval between the longest wavelength pump laser and the wavelength of the optical signal detected by the OSC. pump-final -λ osc ; The equivalent coefficients can be linearly fitted to the wavelength interval, expressed as: K effective =k×Δλ+b; In practical Raman amplifier gain control, the pump power required for the longest wavelength is denoted as P. pump-final-contolling Then P pump-final-contolling = K effective-1 ×P osc-1 +K effective-2 ×P osc-2 +……+K effective-n ×P osc-n In real-time conditions, if the corresponding OSC detects optical signal λ osc-i If the wavelength does not exist, then the parameter P in the corresponding formula... osc-i The value is 0, and i is a parameter value between 1 and n.

6. The control method for eliminating the influence of OSC signal on gain of an ultrawideband Raman amplifier according to claim 4, characterized in that, The control unit, based on the desired light intensity of the amplified data optical signal to be achieved by the transmission optical path, specifically includes: By establishing the relationship between out-of-band ASE and gain, the relationship is as follows: Out-of-band ASE = K × Gain + b + pointloss; the gain is controlled by controlling the power of the out-of-band ASE; where K is the linear relationship constant between the two, b is the influencing parameter, and pointloss is the connection loss between the pump laser and the fiber.

7. A control method for an ultra-wideband Raman amplifier that eliminates the influence of OSC signals on gain, characterized in that, Methods include n pump lasers connected sequentially through multiple multiplexers constitute an ultra-wideband pump optical signal source; each pump laser emits pump laser light in the band it covers. The OSC signal receiving port couples the OSC detection optical signal it acquires with the pump optical signals of the n pump lasers through the first multiplexer. The coupled pump optical signal is then coupled to the transmission optical path through the second multiplexer to complete the pump amplification of the data optical signal and the channel monitoring of the transmission optical path by the OSC detection optical signal. The control unit controls the corresponding n pump lasers to be in a stopped state, thereby multiplexing the pump total power detection photodetector located on the pump main optical path to complete the detection of the OSC detection light signal intensity; The control unit adjusts the optical power of one or more of the n pump lasers under its control, based on the intensity of the OSC-detected optical signal, to be consistent with or close to the frequency band of the OSC-detected optical signal.

8. The control method for eliminating the influence of OSC signal on gain of an ultrawideband Raman amplifier according to claim 7, characterized in that, The control unit controls the corresponding n pump lasers to be in a stopped state, specifically including: Before the n pump lasers are ready to start and enter the working state, the control unit collects the output of the total pump power detection photodetector in real time. If a valid detection result is obtained, it is recorded as the power intensity of the OSC detection optical signal. If no valid detection result is obtained, a request signal is sent to the OSC detection optical signal transmitter so that the optical power detection of the OSC detection optical signal can be completed before the n pump lasers are started and put into operation.

9. The control method for eliminating the influence of OSC signal on gain of an ultrawideband Raman amplifier according to claim 7, characterized in that, When adjusting the optical power of one or more pump lasers among the n pump lasers under its control that have the same or similar frequency band as the OSC detection optical signal, it is confirmed that the pump laser being calibrated and adjusted is the pump laser with the longest wavelength among the n pump lasers. The specific method includes: The power of the longest wavelength pump laser is denoted as P. pump-final The wavelength is denoted as λ. pump-final The power of the optical signal detected by the OSC is denoted as P. osc-1 P osc-2 ...P osc-n The wavelength of the optical signal detected by OSC is denoted as λ. osc , including: λ osc-1、 λ osc-2 ……λ osc-n , n≥1; set the proportionality coefficient of the OSC detection optical signal power to be equivalent to the longest wavelength pump power, denoted as K. effective The wavelength of the optical signal detected by the OSC is Δλ = λ, which is the wavelength interval between the longest wavelength pump laser and the wavelength of the optical signal detected by the OSC. pump-final -λ osc ; The equivalent coefficients can be linearly fitted to the wavelength interval, expressed as: K effective =k×Δλ+b; In practical Raman amplifier gain control, the pump power required for the longest wavelength is denoted as P. pump-final-contolling Then P pump-final-contolling = K effective-1 ×P osc-1 +K effective-2 ×P osc-2 +……+K effective-n ×P osc-n In real-time conditions, if the corresponding OSC detects optical signal λ osc-i If the wavelength does not exist, then the parameter P in the corresponding formula... osc-i The value is 0, and i is a parameter value between 1 and n.

10. The control method for eliminating the influence of OSC signal on gain of an ultrawideband Raman amplifier according to claim 7, characterized in that, The control unit, based on the desired light intensity of the amplified data optical signal to be achieved by the transmission optical path, specifically includes: By establishing the relationship between out-of-band ASE and gain, the relationship is as follows: Out-of-band ASE = K × Gain + b + pointloss; the gain is controlled by controlling the power of the out-of-band ASE; where K is the linear relationship constant between the two, b is the influencing parameter, and pointloss is the connection loss between the pump laser and the fiber.

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