Automatic gain optical fiber amplifier and gain method for optical power loss

Abstract

The application relates to the technical field of optical communication, and provides an automatic gain optical fiber amplifier and a gain method for optical power loss. The automatic gain optical fiber amplifier comprises a preamplifier, a transmission optical fiber, a preamplifier and a gain adjustment module. The initial optical signal is amplified through the preamplifier to obtain an amplified optical signal. The amplified optical signal carries ASE noise. The transmission optical fiber transmits the amplified optical signal to the preamplifier end. The gain adjustment module detects the optical power size of the ASE noise separated from the amplified optical signal to obtain an ASE optical power detection value. The target gain of the preamplifier is dynamically set according to the ASE optical power detection value and an ASE optical power setting value. The preamplifier compensates the amplified optical signal according to the target gain. In the case that the number of wavelengths cannot be determined, the preamplifier can dynamically compensate the optical fiber link loss introduced by the transmission optical fiber according to the target gain.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, and in particular to an automatic gain fiber amplifier and a gain method for optical power loss. Background Technology

[0002] In wavelength division multiplexing (WDM) optical transmission systems, fiber optic amplifiers are essential for compensating for insertion loss in optical devices and power loss in the optical link. Erbium-doped fiber amplifiers (EDBFAs) are the most common type of fiber optic amplifier. EDBFAs generally consist of a preamplifier placed at the fiber input to amplify the service optical signal to a certain input power, and a preamplifier placed at the fiber output to compensate for losses in the optical link.

[0003] Since multiple service beams are transmitted simultaneously in a wavelength division multiplexing (WDM) optical transmission system, and the number of service beams may change dynamically depending on the actual application, the erbium-doped fiber amplifiers in WDM optical transmission systems mostly adopt a constant gain operating mode that matches the fiber link loss. That is, the total input or total output power changes dynamically with the number of service beams, and the constant optical amplifier gain ensures that the power of a single channel remains basically unchanged.

[0004] The gain of a preamplifier is primarily used to compensate for fiber optic link loss. However, fiber optic link loss varies across different application scenarios and can even dynamically change depending on the external environment within the same scenario. Specifically, fiber optic link loss is affected by fiber length, port-to-port insertion loss along the fiber path, and the quality of repair points within the fiber. Furthermore, fiber aging or compression in the external environment also impacts link loss. In practical applications, the optical power detected by the preamplifier is related to both fiber loss and the number of wavelengths of the service light. If there are no other communication methods to transmit the transmitter's power, and the number of wavelengths cannot be determined, the preamplifier cannot automatically select an appropriate gain to match the fiber optic link loss based on its own power detection. Therefore, manual configuration or a network management system is often required to coordinate the power at both the fiber input and output ends, calculate link loss, and configure the preamplifier gain accordingly.

[0005] Therefore, overcoming the shortcomings of the existing technology is an urgent problem to be solved in this technical field. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an automatic gain fiber amplifier and a gain method for optical power loss, which solves the problem that when the number of wavelengths cannot be determined, the preamplifier cannot automatically select an appropriate gain to match the loss of the fiber optic link based on its own detection of optical power.

[0007] The present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an automatic gain fiber amplifier, comprising: a preamplifier, a transmission fiber, a preamplifier, and a gain adjustment module;

[0009] The output of the preamplifier is coupled to one input of the preamplifier via a transmission optical fiber, and is suitable for amplifying the initial optical signal to obtain an amplified optical signal. The amplified optical signal carries ASE noise, which is generated when the preamplifier is working.

[0010] The transmission optical fiber is suitable for transmitting amplified optical signals;

[0011] The input end of the gain adjustment module is coupled to the transmission optical fiber, and the output end of the gain adjustment module is coupled to another input end of the preamplifier. It is suitable for detecting the optical power of ASE noise separated from the amplified optical signal to obtain the ASE optical power detection value, and dynamically setting the target gain of the preamplifier according to the ASE optical power detection value and the ASE optical power setting value.

[0012] The preamplifier is adapted to compensate the amplified optical signal according to the target gain, so as to dynamically compensate for the link loss introduced by the transmission optical fiber.

[0013] Furthermore, the automatic gain fiber amplifier also includes a filter disposed between the preamplifier and the preamplifier, wherein:

[0014] The input end of the filter is coupled to the transmission optical fiber, and one output end of the filter is connected to the gain adjustment module. The amplified optical signal directly reaches the filter after passing through the transmission optical fiber. The filter is suitable for separating ASE noise within a preset wavelength range in the amplified optical signal and sending the ASE noise to the gain adjustment module.

[0015] The other output of the filter is coupled to the preamplifier, and is suitable for transmitting the separated amplified optical signal to the preamplifier.

[0016] Furthermore, the gain adjustment module is also used to calculate the difference between the ASE optical power detection value and the ASE optical power setting value, and use it as the link loss value of the amplified optical signal in the transmission optical fiber;

[0017] The gain adjustment module is also used to set the gain based on the link loss value according to different gain compensation requirements; when it is necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set to be the same as the link loss value; when it is not necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set within a predetermined range of the link loss value.

[0018] Furthermore, the automatic gain fiber amplifier further includes a filter disposed after the preamplifier, wherein:

[0019] The input terminal of the filter is coupled to the output terminal of the preamplifier, and one output terminal of the filter is connected to the gain adjustment module. The amplified optical signal is compensated by the preamplifier and then reaches the filter. The filter is suitable for separating ASE noise within a preset wavelength range in the compensated amplified optical signal and sending the ASE noise to the gain adjustment module.

[0020] Furthermore, the gain adjustment module adjusts the target gain until the ASE optical power detection value detected by the gain adjustment module is equal to the ASE optical power setting value.

[0021] Furthermore, the automatic gain fiber amplifier further includes: a first MCU controller, a first transceiver unit, a second MCU controller, a second transceiver unit, a filler optical signal generator, a local optical signal generator, and a multiplexing device, wherein:

[0022] The local optical signal generator is connected to the multiplexing device and is suitable for sending local service signals to the multiplexing device;

[0023] The filling optical signal generator is connected to the multiplexing device and is adapted to send a filling signal to the multiplexing device;

[0024] The multiplexing device is used to acquire network service signals, as well as one of local service signals and filler signals, and couple the acquired signals into a total service optical signal.

[0025] The first MCU controller is connected to the fill light signal generator and the local service signal generator. When the local service signal is dropped, the first MCU controller controls the fill light signal to send a fill signal to replace the local service signal.

[0026] The first transceiver unit and the second transceiver unit communicate to send a notification message that the local service signal has been dropped to the second MCU controller;

[0027] The second MCU controller is connected to the gain adjustment module and is adapted to control the gain adjustment module to set the gain according to the notification information, so that the preamplifier avoids the optical amplification of the filling signal and modulates the amplified light in the preamplifier to perform gain compensation for the effective optical signal.

[0028] In a second aspect, the present invention provides a method for increasing optical power loss, applied to an automatic gain fiber amplifier as described in the first aspect, comprising:

[0029] The preamplifier amplifies the initial optical signal to obtain an amplified optical signal, wherein the amplified optical signal carries ASE noise, which is generated when the preamplifier is working.

[0030] The gain adjustment module detects the optical power of the ASE noise separated from the amplified optical signal to obtain the ASE optical power detection value.

[0031] The target gain of the preamplifier is dynamically set based on the ASE optical power detection value and the ASE optical power setting value.

[0032] The preamplifier compensates the amplified optical signal according to the target gain to dynamically compensate for the link loss introduced by the transmission optical fiber.

[0033] Furthermore, the gain method also includes:

[0034] The filter receives the amplified optical signal from the transmission optical fiber, separates ASE noise within a preset wavelength range from the amplified optical signal, and sends the ASE noise to the gain adjustment module; or,

[0035] The filter receives the amplified optical signal after compensation by the preamplifier, separates the ASE noise within a preset wavelength range from the compensated amplified optical signal, and sends the ASE noise to the gain adjustment module.

[0036] Furthermore, the step of dynamically setting the target gain of the preamplifier based on the ASE optical power detection value and the ASE optical power setting value specifically involves:

[0037] Calculate the difference between the ASE optical power detection value and the ASE optical power setting value, and use it as the link loss value of the amplified optical signal in the transmission optical fiber;

[0038] Based on different gain compensation requirements, the link loss value is used as a benchmark for gain setting;

[0039] When it is necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set to be the same as the link loss value; when it is not necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set within a predetermined range of the link loss value.

[0040] Furthermore, when the amplified optical signal reaches the filter after preamplifier gain compensation, the dynamic setting of the target gain of the preamplifier based on the ASE optical power detection value and the ASE optical power setting value specifically involves:

[0041] Adjust the target gain until the ASE optical power detection value detected by the gain adjustment module is equal to the ASE optical power setting value.

[0042] Furthermore, the gain method also includes: performing multiplexing loss compensation on the initial optical signal through the preamplifier.

[0043] Furthermore, the gain method also includes:

[0044] When the local service signal is offline, the first MCU controller controls the fill optical signal generator to send a fill signal to the multiplexing device to replace the local service signal;

[0045] The first transceiver unit and the second transceiver unit communicate to send a notification message that the local service signal has been dropped to the second MCU controller;

[0046] The second MCU controller controls the gain adjustment module to set the gain according to the notification information; so that the preamplifier avoids the optical amplification of the fill signal and modulates the amplified light in the preamplifier to perform gain compensation for the effective optical signal;

[0047] Once the local service signal is restored, the preamplifier resumes gain compensation for the entire amplified optical signal.

[0048] In this invention, the initial optical signal is amplified by the preamplifier to obtain an amplified optical signal. The amplified optical signal carries ASE noise. The transmission optical fiber transmits the amplified optical signal to the preamplifier. The gain adjustment module detects the optical power of the ASE noise separated from the amplified optical signal to obtain an ASE optical power detection value. Based on the ASE optical power detection value and the ASE optical power setting value, the target gain of the preamplifier is dynamically set. The preamplifier compensates for the amplified optical signal according to the target gain, so that when the number of wavelengths cannot be determined, the preamplifier can dynamically compensate for the fiber link loss introduced by the transmission optical fiber according to the target gain. Attached Figure Description

[0049] 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.

[0050] Figure 1 This is a schematic diagram of the structure of an automatic gain fiber amplifier provided in an embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of the structure of an automatic gain fiber amplifier (filter preamp) provided in an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of the optical signal spectrum in the automatic gain fiber amplifier provided in an embodiment of the present invention;

[0053] Figure 4 This is a schematic diagram of another automatic gain fiber amplifier (with post-filter) provided in an embodiment of the present invention;

[0054] Figure 5 This is a schematic diagram of the structure of a wavelength division multiplexing system provided in an embodiment of the present invention;

[0055] Figure 6 This is a schematic diagram of another wavelength division multiplexing system provided in an embodiment of the present invention;

[0056] Figure 7 This is a schematic diagram of another structure of an automatic gain fiber amplifier provided in an embodiment of the present invention;

[0057] Figure 8 This is a flowchart illustrating the gain method for reducing optical power loss provided in an embodiment of the present invention;

[0058] Figure 9 This is another flowchart illustrating the gain method for optical power loss provided in an embodiment of the present invention. Detailed Implementation

[0059] 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.

[0060] 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.

[0061] 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.

[0062] Example 1:

[0063] Embodiment 1 of the present invention provides an automatic gain fiber amplifier, such as Figure 1As shown, it includes: a preamplifier, a transmission optical fiber, a preamplifier, and a gain adjustment module.

[0064] The output of the preamplifier is coupled to one input of the preamplifier via a transmission optical fiber, and is suitable for amplifying the initial optical signal to obtain an amplified optical signal. The amplified optical signal carries ASE noise (Amplifier Spontaneous Emission Noise), which is generated when the preamplifier is working.

[0065] The initial optical signal is formed by the coupling of multiple optical signals required for transmission. This process generates multiplexing loss, necessitating a preamplifier to amplify the initial optical signal and compensate for this loss. The preamplifier is a broadband fixed-gain optical preamplifier used to amplify the initial optical signal according to a predetermined gain value to obtain the amplified optical signal. During the compensation process, the preamplifier generates ASE noise, which is incorporated into the amplified optical signal along with the total optical signal.

[0066] In the automatic gain fiber amplifier, as the number of service lights increases, the optical power of the initial optical signal increases linearly proportionally, and the optical power of the amplified optical signal output by the preamplifier also increases linearly proportionally. However, the ASE optical power does not change significantly within a certain wavelength range. In the C-band, especially within a longer wavelength range, the ASE optical power is not sensitive to the optical power of the service light input to the automatic gain fiber amplifier. Therefore, the ASE noise optical power within a certain wavelength range is basically related to the preamplifier gain, and has a weak relationship with the number and power of service lights.

[0067] The transmission optical fiber is suitable for transmitting amplified optical signals. The input of the gain adjustment module is coupled to the transmission optical fiber, and the output of the gain adjustment module is coupled to another input of the preamplifier. This module is used to detect the optical power of ASE noise separated from the amplified optical signal to obtain an ASE optical power detection value, and to dynamically set the target gain of the preamplifier based on the ASE optical power detection value and the ASE optical power setpoint. The preamplifier is used to compensate the amplified optical signal according to the target gain to dynamically compensate for the link loss introduced by the transmission optical fiber.

[0068] The gain adjustment module includes a photodetector and a calculation module. The photodetector is used to detect the optical power of ASE noise to obtain the detected ASE optical power value. The calculation module is used to calculate the target gain based on the detected ASE optical power value and the set ASE optical power value.

[0069] The amplified optical signal incurs link loss during transmission through the transmission optical fiber. Therefore, it needs to be compensated for by a preamplifier, which is a broadband variable gain optical preamplifier used for dynamic compensation. Due to variations in the number of service optical signals, the power of the amplified optical signal changes. Furthermore, the link loss generated during transmission within the transmission optical fiber varies depending on factors such as the fiber's length, quality, aging, and external environment. When the link loss generated during transmission is uncertain, the preamplifier dynamically compensates for the amplified optical signal to increase its power to a predetermined value. This ensures that when the compensated amplified optical signal is decoupled into multiple service optical signals, all of these signals meet the detection range requirements of the service receiver.

[0070] Since the ASE optical power is basically related to the gain of the preamplifier, the ASE optical power at the preamplifier can be obtained based on the gain setting of the preamplifier; that is, the ASE optical power at the preamplifier is the set ASE optical power value. Furthermore, the relationship between the ASE optical power and the service light is weak within a certain wavelength range. However, when passing through the transmission fiber, the ASE noise in the amplified optical signal and the link loss experienced by the total service light are consistent. Therefore, it is possible to measure the optical power of the portion of ASE noise with a weaker relationship to the service light at the preamplifier end, using this as the ASE optical power detection value. A target gain can be set using the ASE optical power detection value and the ASE optical power set value. The preamplifier then dynamically compensates for the link loss introduced by the transmission fiber based on the target gain.

[0071] In this invention, the initial optical signal is amplified by the preamplifier to obtain an amplified optical signal. The amplified optical signal carries ASE noise. The transmission optical fiber transmits the amplified optical signal to the preamplifier. The gain adjustment module detects the optical power of the ASE noise separated from the amplified optical signal to obtain an ASE optical power detection value. Based on the ASE optical power detection value and the ASE optical power setting value, the target gain of the preamplifier is dynamically set. The preamplifier compensates for the amplified optical signal according to the target gain, so that when the number of wavelengths cannot be determined, the preamplifier can dynamically compensate for the fiber link loss introduced by the transmission optical fiber according to the target gain.

[0072] In order to separate the ASE noise that was not amplified by the preamplifier, combined with Figure 2The automatic gain fiber amplifier further includes a filter disposed between the preamplifier and the preamplifier.

[0073] The input end of the filter is coupled to the transmission optical fiber, and one output end of the filter is connected to the gain adjustment module. The amplified optical signal directly reaches the filter after passing through the transmission optical fiber. The filter is suitable for separating ASE noise within a preset wavelength range in the amplified optical signal and sending the ASE noise to the gain adjustment module. The other output end of the filter is coupled to the preamplifier and is suitable for transmitting the separated amplified optical signal to the preamplifier.

[0074] The filter is a bandpass filter, suitable for separating the portion of ASE noise within a preset wavelength range from the amplified optical signal. The separated amplified optical signal includes the total traffic light and the unequal ASE noise. The separated ASE noise is less affected by the optical power of the total traffic light due to its wavelength, and is primarily affected only by the preamplifier.

[0075] The ASE noise within the preset wavelength range refers to the portion of ASE noise that is outside the total service optical wavelength range but within the amplified optical signal wavelength range. Combined with... Figure 3 The spectrum of the amplified optical signal is as follows: Figure 3 The spectrum before filtering is shown in the diagram. The spectrum of the amplified optical signal after some ASE noise has been separated by the filter is shown in the diagram. Figure 3 The filtered spectrum is shown in the schematic diagram. The spectrum of ASE noise within the preset wavelength range is as follows: Figure 3 The spectral diagram of ASE noise within a preset wavelength range is shown in the figure. The total service optical spectrum is in Figure 3 The portion of the spectrum represented by the three arrows indicates the ASE noise spectrum outside the total service optical spectrum. Figure 3 The spectrum is represented by the area between the three arrows and the portion outside the three arrows.

[0076] In this embodiment, the gain adjustment module is also used to calculate the difference between the ASE optical power detection value and the ASE optical power setting value, and use it as the link loss value of the amplified optical signal in the transmission optical fiber.

[0077] The gain adjustment module is also used to set the gain based on the link loss value according to different gain compensation requirements; when it is necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set to be the same as the link loss value; when it is not necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set within a predetermined range of the link loss value.

[0078] Wherein, the ASE optical power setting value is P0, the ASE optical power detection value is P1, the target gain is G, and the link loss value is L0 = P1 - P0; when it is necessary to fully compensate for the link loss of the amplified optical signal, the target gain G = L0 is set, that is, the target gain is set to the link loss value; when it is not necessary to fully compensate for the link loss of the amplified optical signal, a gain difference ΔP is set, and the target gain G = L0 ± ΔP is set, that is, the target gain is set within a predetermined range of the link loss value.

[0079] For example, if the link loss is 10dB and full compensation is required, the preamplifier gain is 10dB so that the optical power of the amplified optical signal output by the preamplifier is the same as that of the amplified optical signal output by the preamplifier. If incomplete compensation is required, the preamplifier gain can be 8dB so that the optical power of the amplified optical signal output by the preamplifier is 2dB less than that of the amplified optical signal output by the preamplifier.

[0080] In order to separate the ASE noise amplified by the preamplifier, combined with Figure 4 The automatic gain fiber amplifier further includes a filter, which is positioned after the preamplifier. Distinguished from... Figure 2 In this embodiment, the filter is placed after the preamplifier, that is, the ASE noise will pass through the preamplifier, and the ASE noise detection value is the value after compensation by the preamplifier.

[0081] The input terminal of the filter is coupled to the output terminal of the preamplifier, and one output terminal of the filter is connected to the gain adjustment module. The amplified optical signal is compensated by the preamplifier and then reaches the filter. The filter is suitable for separating ASE noise within a preset wavelength range in the compensated amplified optical signal and sending the ASE noise to the gain adjustment module.

[0082] In this process, after the amplified optical signal is compensated by the preamplifier, the ASE noise and the total service light contained in the amplified optical signal are also compensated by the gain of the preamplifier. At this time, the filter separates the ASE noise that is not within the wavelength range of the total service light from the amplified optical signal and sends this part of the ASE noise to the gain adjustment module. The gain adjustment module configures the target gain based on this part of the ASE noise.

[0083] In this embodiment, after receiving ASE noise, the gain adjustment module obtains the ASE optical power detection value based on the ASE noise. The gain adjustment module adjusts the target gain based on the ASE optical power detection value until the ASE optical power detection value detected by the gain adjustment module is equal to the ASE optical power setting value.

[0084] Specifically, such as Figure 3 As shown, in the spectrum of the amplified optical signal, a portion of the ASE noise wavelength is outside the total service optical wavelength range. At this time, after this portion of ASE noise is amplified by the preamplifier, it passes through the filter and is detected by the gain adjustment module. The detected ASE optical power detection value is recorded as P3, and the ASE optical power setting value is recorded as P2. Then, the target gain needs to be gradually adjusted so that the ASE optical power setting value is equal to the ASE optical power detection value, P3 = P2, so that the optical power of the compensated amplified optical signal is within the detection range required by the service receiver.

[0085] In this embodiment, the automatic gain fiber amplifier further includes a multiplexing device and a demultiplexing device, and the automatic gain fiber amplifier is installed in a wavelength division multiplexing system. The input terminal of the preamplifier is coupled to the multiplexing device, and is suitable for receiving the combined total service optical signal and performing preset gain compensation on the optical signal; the multiplexing device is suitable for coupling multiple service optical signals into the total service optical signal. Figure 5 In the illustrated scheme, the output of the preamplifier is coupled to the wavelength division device, which is suitable for gain compensation of the amplified optical signal and sending the compensated optical signal to the wavelength division device. The wavelength division device is suitable for dividing the total service optical signal. Figure 6 In the scheme shown, the output of the filter is coupled to the multiplexing device, and the filter is also used to send the gain-compensated optical signal to the multiplexing device.

[0086] To reduce the output power of the preamplifier for the corresponding dropped optical band and improve the gain compensation effect for the effective optical signal when some service optical signals are dropped, the automatic gain fiber amplifier is combined with... Figure 7 The automatic gain fiber amplifier further includes: a first MCU controller, a first transceiver unit, a second MCU controller, a second transceiver unit, a filler optical signal generator, and a local optical signal generator.

[0087] The local optical signal generator is connected to the multiplexing device and is adapted to send local service signals to the multiplexing device; the filling optical signal generator is connected to the multiplexing device and is adapted to send filling signals to the multiplexing device; the multiplexing device is used to acquire network service signals, as well as one of the local service signals and the filling signals, and couple the acquired signals into a total service optical signal.

[0088] The first MCU controller is connected to the fill light signal generator and the local service signal generator. When the local service signal is dropped, the first MCU controller controls the fill light signal to send a fill signal to replace the local service signal.

[0089] Specifically, when the local optical signal is not disconnected, the multiplexing device couples the network service signal and the local service signal into a total service optical signal. When the local optical signal is disconnected, the multiplexing device couples the network service signal and the filler signal into a total service optical signal. The filler signal serves to occupy the channel of the local optical signal when the local optical signal is disconnected, preventing the channel from being occupied after the local optical signal is disconnected, which would require channel reallocation when the local optical signal recovers, thus affecting the transmission efficiency of the optical signal.

[0090] The first transceiver unit and the second transceiver unit communicate to send a notification message of a local service signal drop to the second MCU controller; the second MCU controller is connected to the gain adjustment module and is adapted to control the gain adjustment module to set the gain according to the notification message, so that the preamplifier avoids the optical amplification of the filler signal and modulates the amplified light in the preamplifier to perform gain compensation for the effective optical signal.

[0091] When the local optical signal drops, the second MCU controller obtains notification information about the dropped local optical signal from the first transceiver unit through the second transceiver unit. The second MCU controller then controls the gain adjustment module to set the gain, adjusting the settings of the preamplifier. Ultimately, the preamplifier performs gain compensation for the effective optical signal in the amplified optical signal, ensuring that the preamplifier does not process the filler signal in the amplified optical signal. This is significant because it concentrates the output power of the preamplifier on the effective optical signal in the amplified signal, without losing additional output power in the filler signal, thus improving the power utilization and gain compensation effect of the preamplifier.

[0092] When the local optical signal is recovered, the preamplifier is reset to compensate the overall gain of the amplified optical signal.

[0093] In the above extended implementation method, the dropped signal can be a local service signal or one or more network service signals. For the latter, the corresponding filler optical signal can also be generated locally. The subsequent solution is similar to the above extended implementation method, and will not be elaborated further here.

[0094] Example 2:

[0095] This invention provides a gain method for reducing optical power loss, applied to the automatic gain fiber amplifier as described in Embodiment 1, combined with... Figure 8 The gain method includes:

[0096] Step 101: The preamplifier amplifies the initial optical signal to obtain an amplified optical signal, wherein the amplified optical signal carries ASE noise, which is generated when the preamplifier is working.

[0097] The initial optical signal is formed by the coupling of multiple optical signals required for transmission. This process generates multiplexing loss, necessitating a preamplifier to amplify the initial optical signal and compensate for this loss. The preamplifier is a broadband fixed-gain optical preamplifier used to amplify the initial optical signal according to a predetermined gain value to obtain the amplified optical signal. During the compensation process, the preamplifier generates ASE noise, which is incorporated into the amplified optical signal along with the total optical signal.

[0098] Step 102: The gain adjustment module detects the optical power of the ASE noise separated from the amplified optical signal to obtain the ASE optical power detection value.

[0099] As the number of service optical signals increases, the optical power of the initial optical signal increases linearly and proportionally, as does the optical power of the amplified optical signal output by the preamplifier. However, the ASE optical power does not change significantly within a certain wavelength range. In the C-band, especially within a longer wavelength range, the ASE optical power is not sensitive to the optical power of the service optical signal input to the automatic gain fiber amplifier. Therefore, the ASE noise optical power within a certain wavelength range is basically related to the preamplifier gain, and has a weak relationship with the number and power of service optical signals.

[0100] Step 103: Dynamically set the target gain of the preamplifier based on the ASE optical power detection value and the ASE optical power setting value.

[0101] Since the ASE optical power is basically related to the gain of the preamplifier, the ASE optical power at the preamplifier can be obtained based on the gain setting of the preamplifier; that is, the ASE optical power at the preamplifier is the set ASE optical power value. Furthermore, the relationship between the ASE optical power and the service light is weak within a certain wavelength range. However, when passing through the transmission fiber, the ASE noise in the amplified optical signal and the link loss experienced by the total service light are consistent. Therefore, it is possible to measure the optical power of the portion of ASE noise with a weaker relationship to the service light at the preamplifier end as the ASE optical power detection value. A target gain can be set using the ASE optical power detection value and the ASE optical power set value. The preamplifier then dynamically compensates for the link loss introduced by the transmission fiber based on the target gain.

[0102] Step 104: The preamplifier compensates the amplified optical signal according to the target gain to dynamically compensate for the link loss introduced by the transmission optical fiber.

[0103] The amplified optical signal incurs link loss during transmission through the optical fiber, necessitating gain compensation. The preamplifier is a broadband variable gain optical preamplifier used for dynamic compensation of the amplified optical signal. Due to variations in the number of service optical signals, the power of the amplified optical signal changes, and the link loss generated during transmission within the optical fiber is not uniform. Therefore, given the uncertainty of the link loss, the preamplifier dynamically compensates for the amplified optical signal to increase its optical power to a predetermined value. This ensures that when the compensated amplified optical signal is decoupled into multiple service optical signals, all of these signals meet the detection range requirements of the service receiver.

[0104] In this embodiment, the gain method further includes: a filter receiving the amplified optical signal from the transmission optical fiber, separating ASE noise within a preset wavelength range from the amplified optical signal, and sending the ASE noise to the gain adjustment module; or, a filter receiving the amplified optical signal after compensation by the preamplifier, separating ASE noise within a preset wavelength range from the compensated amplified optical signal, and sending the ASE noise to the gain adjustment module.

[0105] The ASE noise within the preset wavelength range refers to the portion of ASE noise that is outside the total service optical wavelength range but within the amplified optical signal wavelength range.

[0106] When the filter is located between the preamplifier and the preamplifier, and the amplified optical signal directly reaches the filter through the transmission optical fiber, step 103 specifically includes:

[0107] The difference between the ASE optical power detection value and the ASE optical power setting value is calculated and used as the link loss value of the amplified optical signal in the transmission optical fiber. Based on different gain compensation requirements, the link loss value is used as a reference for gain setting. Wherein, the optical power setting value is P0, the ASE optical power detection value is P1, and the target gain is G, then the optical fiber link loss value L0 = P1 - P0.

[0108] When it is necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set to be the same as the link loss value; when it is not necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set within a predetermined range of the link loss value.

[0109] Specifically, when it is necessary to fully compensate for the link loss of the amplified optical signal, the target gain G = L0 = P1 - P0 is set, that is, the target gain is set to the fiber link loss value; when it is not necessary to fully compensate for the link loss of the amplified optical signal, a gain difference ΔP is set, and the target gain G = L0 ± ΔP = P1 - P0 ± ΔP is set, that is, the target gain is set within a predetermined range of the link loss value.

[0110] When the filter is located after the preamplifier, and the amplified optical signal reaches the filter after gain compensation by the preamplifier, step 103 specifically includes: adjusting the target gain until the ASE optical power detection value detected by the gain adjustment module is equal to the ASE optical power setting value.

[0111] In this case, a portion of the ASE noise has a wavelength outside the total service optical wavelength range. At this time, the optical power of this portion of ASE noise after being amplified by the preamplifier is the ASE optical power set value, which is denoted as P2. The ASE optical power detection value of this portion of ASE noise detected by the gain adjustment module is P3. Then, the target gain is adjusted to maintain the ASE optical power set value equal to the ASE optical power detection value, P3 = P2, so that the optical power of the compensated amplified optical signal is within the detection range requirement of the service receiver.

[0112] In this embodiment, the gain method further includes: compensating for the multiplexing loss of the initial optical signal using the preamplifier. When multiple service optical signals are coupled together in the multiplexing device to form the initial optical signal, multiplexing loss occurs. Therefore, the preamplifier is needed to amplify the initial optical signal to compensate for the multiplexing loss.

[0113] In order to effectively utilize the output power of the preamplifier, combined with Figure 9 The gain method further includes:

[0114] Step 201: When the local service signal is offline, the first MCU controller controls the fill optical signal generator to send a fill signal to the multiplexing device to replace the local service signal.

[0115] The filler optical signal replaces the dropped local service signal, and the multiplexing device couples the network service signal and the filler signal into the total service optical signal.

[0116] Step 202: The first transceiver unit and the second transceiver unit communicate to send a notification message that the local service signal has been dropped to the second MCU controller.

[0117] The first MCU controller and the second MCU controller communicate through the first transceiver unit and the second transceiver unit, so that the second MCU controller can obtain information about the local service signal being dropped.

[0118] Step 203: The second MCU controller controls the gain adjustment module to set the gain according to the notification information; so that the preamplifier avoids the optical amplification of the fill signal and modulates the amplified light in the preamplifier to perform gain compensation for the effective optical signal.

[0119] In this preamplifier, under the corresponding gain setting, the effective signal in the amplified optical signal is gain compensated, while the band of the filler signal is not processed. This concentrates the output power of the preamplifier on the effective optical signal in the amplified signal, without losing additional output power in the filler signal, thereby improving the power utilization and gain compensation effect of the preamplifier.

[0120] Step 204: After the local service signal is restored, the preamplifier restores the overall gain compensation for the amplified optical signal.

[0121] When the local optical signal is recovered, the preamplifier is reset to compensate the overall gain of the amplified optical signal.

[0122] The specific implementation of the automatic gain fiber amplifier is detailed in Embodiment 1, and will not be repeated here.

[0123] The above description is merely 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 automatic gain fiber amplifier, characterized in that, include: Preamplifier, transmission fiber, preamplifier and gain adjustment module; The output of the preamplifier is coupled to one input of the preamplifier via a transmission optical fiber, and is suitable for amplifying the initial optical signal to obtain an amplified optical signal. The amplified optical signal carries ASE noise, which is generated when the preamplifier is working. The transmission optical fiber is suitable for transmitting amplified optical signals; The input end of the gain adjustment module is coupled to the transmission optical fiber, and the output end of the gain adjustment module is coupled to another input end of the preamplifier. It is suitable for detecting the optical power of ASE noise separated from the amplified optical signal to obtain the ASE optical power detection value, and dynamically setting the target gain of the preamplifier according to the ASE optical power detection value and the ASE optical power setting value. The preamplifier is adapted to compensate the amplified optical signal according to the target gain, so as to dynamically compensate for the link loss introduced by the transmission optical fiber; The automatic gain fiber amplifier further includes: a first MCU controller, a first transceiver unit, a second MCU controller, a second transceiver unit, a filler optical signal generator, a local optical signal generator, and a multiplexing device. The local optical signal generator is connected to the multiplexing device and is used to send local service signals to the multiplexing device. The filler optical signal generator is connected to the multiplexing device and is used to send filler signals to the multiplexing device. The multiplexing device is used to acquire one of the network service signals, the local service signals, and the filler signals, and couple the acquired signals into a total service optical signal. The first MCU controller is connected to the filler optical signal generator and the local service signal generator. When the local service signal is dropped, the first MCU controller is used to control the filler optical signal generator to send a filler signal to replace the local service signal. The first transceiver unit and the second transceiver unit communicate to send a notification message of the local service signal being dropped to the second MCU controller. The second MCU controller is connected to the gain adjustment module and is used to control the gain adjustment module to set the gain according to the notification message, so that the preamplifier avoids optical amplification of the filler signal and modulates the amplified light in the preamplifier to perform gain compensation for the effective optical signal.

2. The automatic gain fiber amplifier according to claim 1, characterized in that, The automatic gain fiber amplifier further includes a filter, which is disposed between the preamplifier and the preamplifier, wherein: The input end of the filter is coupled to the transmission optical fiber, and one output end of the filter is connected to the gain adjustment module. The amplified optical signal directly reaches the filter after passing through the transmission optical fiber. The filter is suitable for separating ASE noise within a preset wavelength range in the amplified optical signal and sending the ASE noise to the gain adjustment module. The other output of the filter is coupled to the preamplifier, and is suitable for transmitting the separated amplified optical signal to the preamplifier.

3. The automatic gain fiber amplifier according to claim 2, characterized in that, The gain adjustment module is also used to calculate the difference between the ASE optical power detection value and the ASE optical power setting value, and use it as the link loss value of the amplified optical signal in the transmission optical fiber; The gain adjustment module is also used to set the gain based on the link loss value according to different gain compensation requirements; when it is necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set to be the same as the link loss value; when it is not necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set within a predetermined range of the link loss value.

4. The automatic gain fiber amplifier according to claim 1, characterized in that, The automatic gain fiber amplifier further includes a filter, which is disposed after the preamplifier, wherein: The input terminal of the filter is coupled to the output terminal of the preamplifier, and one output terminal of the filter is connected to the gain adjustment module. The amplified optical signal is compensated by the preamplifier and then reaches the filter. The filter is suitable for separating ASE noise within a preset wavelength range in the compensated amplified optical signal and sending the ASE noise to the gain adjustment module. The gain adjustment module adjusts the target gain until the ASE optical power detection value detected by the gain adjustment module is equal to the ASE optical power setting value.

5. A gain method for optical power loss, applied to an automatic gain fiber amplifier as described in any one of claims 1 to 4, characterized in that, include: The preamplifier amplifies the initial optical signal to obtain an amplified optical signal, wherein the amplified optical signal carries ASE noise, which is generated when the preamplifier is working. The gain adjustment module detects the optical power of the ASE noise separated from the amplified optical signal to obtain the ASE optical power detection value. The target gain of the preamplifier is dynamically set based on the ASE optical power detection value and the ASE optical power setting value. The preamplifier compensates the amplified optical signal according to the target gain to dynamically compensate for the link loss introduced by the transmission optical fiber.

6. The gain method for optical power loss according to claim 5, characterized in that, The gain method further includes: The filter receives the amplified optical signal from the transmission optical fiber, separates ASE noise within a preset wavelength range from the amplified optical signal, and sends the ASE noise to the gain adjustment module; or, The filter receives the amplified optical signal after compensation by the preamplifier, separates the ASE noise within a preset wavelength range from the compensated amplified optical signal, and sends the ASE noise to the gain adjustment module.

7. The gain method for optical power loss according to claim 6, characterized in that, The specific steps for dynamically setting the target gain of the preamplifier based on the ASE optical power detection value and the ASE optical power setting value are as follows: Calculate the difference between the ASE optical power detection value and the ASE optical power setting value, and use it as the link loss value of the amplified optical signal in the transmission optical fiber; Based on different gain compensation requirements, the link loss value is used as a benchmark for gain setting; When it is necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set to be the same as the link loss value; when it is not necessary to fully compensate for the link loss of the amplified optical signal, the target gain is set within a predetermined range of the link loss value.

8. The gain method for optical power loss according to claim 6, characterized in that, When the amplified optical signal reaches the filter after preamplifier gain compensation, the specific steps of dynamically setting the target gain of the preamplifier based on the ASE optical power detection value and the ASE optical power setting value are as follows: Adjust the target gain until the ASE optical power detection value detected by the gain adjustment module is equal to the ASE optical power setting value.

9. The gain method for optical power loss according to claim 5, characterized in that, The gain method further includes: When the local service signal is lost, the first MCU controller controls the fill optical signal generator to send a fill signal to the multiplexing device to replace the local service signal; The first transceiver unit and the second transceiver unit communicate to send a notification message that the local service signal has been dropped to the second MCU controller. The second MCU controller controls the gain adjustment module to set the gain according to the notification information, so that the preamplifier avoids the optical amplification of the filler signal and modulates the amplified light in the preamplifier to perform gain compensation for the effective optical signal; Once the local service signal is restored, the preamplifier resumes gain compensation for the entire amplified optical signal.

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