44 results about "Raman amplifiers" patented technology

The invention discloses an optical fiber signal transmission system and method based on quantum noise encryption, and relates to the technical field of optical fiber communication, and the system comprises a composite modulation transmitting module, a dispersion compensation relay module, a coherent receiving module and a digital signal processor. The composite modulation transmitting module comprises an electro-optical modulator and a quantum noise randomization encoder; the dispersion compensation relay module comprises an adjustable dispersion compensator and a Raman amplifier; the coherent receiving module comprises a local oscillator laser and a 90-degree optical mixer; a digital signal processor includes a clock recovery unit and a maximum likelihood sequence detector. All the modules are sequentially connected and cooperatively work. And the adjustable dispersion compensator dynamically applies reverse dispersion compensation calculated based on a dispersion coefficient and a transmission distance according to the dispersion amount monitored in real time. According to the invention, through technologies of quantum noise encryption, dynamic dispersion compensation, Raman amplification, coherent reception and the like, safe and efficient transmission with single-wave 400Gbps and 100km transmission bit error rate less than or equal to 1 * 10 <-12 > is realized.

The embodiment of the invention provides a gain regulation and control precision maintenance method for a programmable Raman amplifier. The method comprises the following steps: acquiring basic scene sample data and target scene sample data to form a source domain sample data set and a target domain sample data set; selecting a proper machine learning method as a basic learning algorithm according to the characteristics of the data in the data set; initializing weights occupied by a source domain sample and a target domain sample; fitting a prediction model by adopting a basic learning algorithm according to the weights of the source domain sample and the target domain sample; re-weighting the source domain sample and the target domain sample according to the total weighting error of the target domain sample so as to correct the difference between the distribution of the source domain sample and the distribution of the target domain sample; and obtaining a model after multiple iterations as a pumping prediction model of the programmable Raman amplifier. When the use scene of the programmable Raman amplifier changes and the accuracy of the regulation and control algorithm of the programmable Raman amplifier is reduced, by means of the method, maintenance of the gain regulation and control precision of the programmable Raman amplifier can be achieved by collecting a small amount of sample data, and the use scene of the programmable Raman amplifier is effectively expanded.

Embodiments of the present disclosure comprise an optical amplifier system, with the system comprising an erbium-doped fiber amplifier comprising a C band EDFA configured to generate C band light, and an L band EDFA configured to generate L Band light. A Raman amplifier comprising a fiber span may be pumped using a backward pump light.

The application discloses a self-adaptive Raman gain compensation system and method, and relates to the technical field of optical communication, wherein the self-adaptive Raman gain compensation system comprises: an optical fiber link; a Raman optical amplifier used for amplifying an input optical signal transmitted by the optical fiber link; a centralized optical amplifier used for amplifying an optical signal output by the Raman optical amplifier; and a compensation device used for acquiring and comparing partial optical powers of the input optical signal and the optical signal output by the centralized optical amplifier, and controlling the gain of the centralized optical amplifier based on a comparison result. The application can realize self-adaptive gain compensation when the gain of the Raman amplifier is insufficient.

Systems and methods for operating a passive optical network (PON) extender. The methods comprise: receiving, by the PON extender, a first optical signal from a remote node device of a passive optical network via a first optical link; amplifying the first optical signal using a Raman amplifier of the PON extender to obtain a first Raman amplified optical signal; amplifying the first Raman amplified optical signal using a first optical amplifier of the PON extender to obtain an amplified uplink signal (wherein the first optical amplifier is different than the Raman amplifier); and passing the amplified uplink signal to an optical line terminal via a second optical link (wherein the optical line terminal is disposed locally at a hub site along with the PON extender).

The application discloses a kind of optical frequency standard optical fiber precision transmission systems and methods of remote phase noise compensation, the system includes laser light source, optical fiber, first acoustooptic modulator, Raman amplifier, laser light source is used to simulate optical frequency standard signal, optical fiber is used to transmit optical frequency standard signal;First acoustooptic modulator is connected with laser light source by first optical fiber coupler, first optical isolator, for frequency shift to laser;Raman amplifier is connected with optical fiber, optical frequency standard signal enters optical fiber after first acoustooptic modulator, and the power of optical signal is amplified using Raman amplifier.The application obtains optical fiber phase noise signal by the light heterodyne detection of the phase-locked loop at the far end of optical fiber, and the working frequency of acoustooptic modulator is controlled by negative feedback to compensate optical fiber phase noise in real time, reduce the influence of phase noise on optical frequency standard signal frequency stability, solve the limitation of transmission end position of traditional method, and be applicable to the transmission of optical frequency standard of multiport output mode.

A Raman amplifier includes: a Raman amplification optical fiber configured to Raman amplify incoherent light in which relative intensity noise (RIN) is suppressed while transmitting the incoherent light; and a pumping light source configured to supply pumping light to the Raman amplification optical fiber, in which a corner frequency fc [Hz] at which the suppression of the RIN starts in the Raman-amplified incoherent light is estimated by using the following Equation (1): fc=1 / (D·Δλ·L) (1), in which a full width at half maximum of a wavelength spectrum of the incoherent light is Δλ [nm], a length of the Raman amplification optical fiber is L [km], and an absolute value of chromatic dispersion of the Raman amplification optical fiber at a center wavelength of the incoherent light is D [ps / nm / km].

The invention discloses an O-band Raman amplifier gain optimization design method based on a tree species optimization algorithm. The method comprises the following steps: randomly selecting a plurality of groups of pumping parameters as initial tree species; calculating a Raman amplifier gain value of the initial tree species, taking the Raman amplifier gain value as a fitness value of an optimization algorithm, and performing gain adjustment on the initial tree species to obtain dominant tree species; randomly generating multiple groups of first tree species and second tree species near the dominant tree species, and combining the first tree species and the second tree species as second-generation tree species; calculating a second-generation fitness value of the second-generation tree species, and performing iterative optimization on the second-generation fitness value for a plurality of times according to the steps to obtain an optimal fitness value; and outputting the corresponding optimal tree species according to the optimal fitness value. According to the invention, the problem of multi-objective optimization of pumping parameters is solved, and the transmission distance of O-band signals is effectively improved.

A light source includes a seed light source and a booster amplifier. The seed light source outputs incoherent seed light having a predetermined bandwidth. The booster amplifier serves as a semiconductor optical amplifier that optically amplifies the seed light entered through a first end facet and outputs the amplified light through a second end facet. The booster amplifier has nL being set, which is the product of a refractive index n and a chip length L, so that relative intensity noise (RIN) and ripple are simultaneously suppressed in the amplified light.

A Raman amplifier includes a first light source that outputs a primary pumping light, which propagates in a same direction as a propagation direction of a signal light, to an optical transmission line for Raman amplification, a second light source that outputs a secondary pumping light, which pumps and amplifies the primary pumping light and propagates in the same direction as the propagation direction, to the optical transmission line, and a control unit that controls a gain for the signal light by adjusting power of the secondary pumping light.

Systems and methods include receiving inputs comprising a Raman gain target for a Raman amplifier, fiber parameters, and fiber characteristics, each for an optical span; analyzing the inputs with a deep neural network (DNN) having a plurality of layers; providing a plurality of outputs from the DNN; and utilizing the plurality of outputs for a link budget calculation on the optical span. The Raman amplifier includes a plurality of pumps each at a fixed wavelength.

The invention provides a Raman amplifier reflected light processing method and system based on weak etching optical fibers, and relates to the technical field of passive optical networks. The method comprises the steps that pump light parameters and surface roughness parameters of weak etching optical fibers are obtained, the pump light parameters comprise pump light power, a prediction reflection domain is generated through a Rayleigh back scattering model, and the prediction reflection domain comprises predicted reflection spectrum peak displacement and a diffusion area; constructing a multi-layer spectrum grid module for the prediction reflection domain, generating a spectrum coordinate unit, and mapping the prediction reflection domain into a coordinate unit mark; and based on the coordinate unit marks, performing non-overlapping comparison of the overall size of the reflected light and the marks to generate an overall verification result, and when there is no fitting conflict, outputting a final reflected light intensity distribution. The dynamic suppression of the reflected light induced noise is realized under the condition of not depending on additional hardware components, and the system has the advantages of system flexibility and cost efficiency.

Systems and methods for clamping Raman gains are provided. According to one implementation, a method includes a step of limiting a gain of a Raman amplifier after maintenance or repair of a fiber span, where the Raman amplifier is configured to amplify optical signals propagating over the fiber span. The method also includes a step of obtaining local power measurements. Based on the local power measurements, the method includes a step of increasing the gain of the Raman amplifier. Furthermore, according to another implementation, an optical amplifier assembly may include a Raman amplifier configured to amplify optical signals propagating over a fiber span and a control device configured to limit a gain of the Raman amplifier after maintenance or repair of the fiber span.

A resonating optical amplifier includes a laser pump cavity defined by a first mirror and a second mirror with a laser pump gain medium configured within a first portion of the laser pump cavity and a Raman amplifier within a second portion of the laser pump cavity. A circulating pump-laser light is introduced to the laser pump gain medium forming a pump signal that is configured to bi-directionally propagate along a beam path within the laser pump cavity. The Raman amplifier is positioned in line with the beam path of the pump signal and operable to impart gain on a seed pulse. The seed pulse and the pump signal are co-aligned and linearly polarized.

The embodiment of the invention provides a Raman amplifier gain adjustment method which comprises the following steps: adjusting DRA-P pumping configuration according to a first preset adjustment target, and determining a third preset adjustment target of a preset virtual intermediate point position according to amplifier performance parameters of a receiving end and a second preset adjustment target of a receiving end OSNR, and adjusting the transmitting terminal configuration of the transmitting terminal according to a third preset adjustment target, detecting the actual OSNR of the receiving terminal, and when the actual OSNR does not meet a second preset adjustment target, circularly and finely tuning the DRA-P pumping configuration and / or the transmitting terminal configuration until the actual OSNR meets the second preset adjustment target. According to the embodiment of the invention, segmented decoupling is carried out on the C + L system, and the gain of the amplifier is adjusted and optimized according to the sequence of the receiving end, the transmitting end and the whole, so that the problem that in the prior art, the stimulated Raman scattering effect exists between the pumping wavelengths of the Raman amplifier in the C + L system and between the service light of the C wave band and the service light of the L wave band can be solved; and the overall optical signal-to-noise ratio performance of the C + L system is influenced.

The present invention relates to a reverse design method and system for a backward multi-pumped Raman fiber amplifier, belonging to the field of Raman fiber amplifiers. An improved particle swarm optimization algorithm is first used to optimize the pump light parameter configuration. A neural network algorithm is then used to learn the nonlinear mapping relationship between output gain and pump light parameters to reversely design the Raman fiber amplifier. By determining the target output gain and generating matching pump light parameters, this method replaces the traditional method of numerically solving the Raman coupled wave differential equation. By combining the improved particle swarm optimization algorithm with the neural network, the accuracy of the neural network model is improved, resulting in a Raman fiber amplifier designed for C+L band signal light amplification. This improves computational efficiency and enhances the output gain and output gain flatness of the Raman amplifier.

This application provides a method and system for ultra-long-distance fiber optic frequency transmission. The method includes: establishing a first objective function, which is used to calculate the first Allan variance of the bidirectional gain unit when adjusting its configuration; establishing a second objective function, which is used to calculate the second Allan variance at both ends of the fiber optic link when adjusting the gain power distribution at both ends of the distributed Raman amplifier; calculating the total Allan variance of the fiber optic link based on the first and second Allan variances; and recording the configuration of the bidirectional gain unit and the gain power values ​​of the distributed Raman amplifier at both ends as a static parameter configuration combination when the total gain power of the bidirectional gain unit and the distributed Raman amplifier is greater than the loss of the fiber optic link and the total Allan variance is minimized. This solves the problems of difficult deployment and limited reliability in long-distance fiber optic transmission.

The invention relates to the technical field of optical fiber communication, and provides a third-order Raman amplification method, system and device. The pumping unit of the third-order Raman amplifier outputs the pumping light, and the signal emission unit outputs the signal light; the signal light passes through the transmission unit and then is combined with the pump light to obtain an output signal; the signal receiving unit collects signal power and OSNR data of the output signal and takes the signal power and the OSNR data as experimental reference data; training a PINN model by using system parameters to obtain an intermediate model; performing forward simulation and / or reverse parameter identification by using the intermediate model to obtain an output result; and comparing the output result with experimental reference data, when an error exceeds a preset threshold value, re-training the PINN model until a new error is less than or equal to the preset threshold value to obtain a target model, and completing forward simulation and / or reverse parameter identification by using the target model and the third-order Raman amplifier. The problems that an existing third-order Raman amplifier uses a traditional modeling method and is low in precision and poor in efficiency are solved.

The present invention discloses a Raman amplification system, which comprises: a pump source, which emits a Raman amplification signal with a wavelength of λ P The pump light is split into two beams by the spectrometer: one beam is used as the pump light of the Raman amplifier, which passes through the time delay device and the amplifier, and after the beam aperture adjustment and collimation of the first telescope device, passes through the first dichroic mirror at 45 degrees, and enters the Raman amplifier composed of the first Raman crystal, the first plane mirror, and the second plane mirror; the other beam is reflected by the third plane mirror and injected into the Raman oscillator to generate a wavelength of λ S The Stokes light of the Raman oscillator is composed of a fourth plane reflector, a second Raman crystal, and a concave reflector; the wavelength is λ S The Stokes light is adjusted and collimated by the second telescope device, reflected by the 45° second dichroic mirror and the first dichroic mirror, and then enters the Raman amplifier.

The application provides a kind of distributed optical fiber sensing system and signal processing method, belong to optical fiber sensing technical field.The distributed optical fiber sensing system light signal generating device, acoustooptic modulator, first erbium-doped fiber amplifier, circulator, first Raman amplifier, erbium-doped fiber, sensing optical fiber, coupler, photoelectric balance detector, signal acquisition device and data processing module.The application is amplified to the light signal that enters sensing optical fiber before light signal enters sensing optical fiber by first erbium-doped fiber amplifier and first Raman amplifier, so as to improve the transmission distance of light signal in sensing optical fiber, then the transmission distance of light signal is further improved by the erbium-doped fiber added in sensing optical fiber, so that sensing optical fiber can produce backscattering light signal carrying vibration signal at a farther distance, and the backscattering light signal intensity map is obtained after the backscattering light signal is processed, so that long-distance signal monitoring is realized.

A device, system, and method for distributed Raman amplification of a multi-core fiber (MCF) is disclosed. The optical amplifier device includes a plurality of single mode optical pumps configured to supply one or more wavelengths to a depolarizer and a mode multiplexer configured to receive the one or more wavelengths from the depolarizer to output at least one combined depolarized optical light comprising the one or more wavelengths. The device also includes a coupler to couple the at least one combined depolarized optical light into MCF. The combined depolarized optical light Raman amplifies an optical signal in the MCF.

The present application relates to the technical field of optical communication, and particularly relates to a fiber splice loss calculation method and device, communication equipment and a storage medium. The fiber splice loss calculation method is applied to an optical communication system, the optical communication system comprises transmission optical fibers and a Raman amplifier connected with each other; the method comprises the following steps: setting a target gain, driving the optical communication system to work according to the target gain, obtaining an initial splice loss, an initial gain and an initial total pump power; continuously monitoring real-time gain and real-time total pump power of the optical communication system, obtaining a splice loss real-time change amount based on the real-time gain, the real-time total pump power, the initial gain and the initial splice loss; and adding the splice loss real-time change amount to the initial splice loss to obtain real-time splice loss. The present application can ensure the stability and reliability of signal light transmission.

This invention provides a dynamic multi-band optical network transmission capacity optimization method based on GSNR sensing. The method constructs a nonlinear mapping model between the GSNR characteristics of the input signal and the GSNR characteristics of the output signal, using Raman amplifier pump configuration parameters. This model senses the GSNR characteristics of the input signal in real time and predicts changes in the GSNR distribution of the output signal, thus accurately predicting the GSNR distribution under dynamic input scenarios. By combining intelligent optimization algorithms to dynamically adjust the pump configuration parameters of the Raman amplifier, real-time sensing and precise control of the transmission system's GSNR are achieved, thereby improving the average GSNR and flatness of the channel in the optical network and significantly increasing transmission capacity. This method improves the transmission capacity of dynamic multi-band optical networks, effectively solves the adaptability problem of traditional methods in dynamic scenarios, and significantly improves the performance and stability of optical networks.

The application discloses a real-time monitoring method and a sensing system for a catenary cable state based on distributed optical fiber sensing, and the Mach-Zehnder interference and phi-OTDR fusion type distributed optical fiber sensing system comprises a first light source, a second light source, a Mach-Zehnder interferometer, a phi-OTDR and a data acquisition and processing module; Raman amplifiers are arranged at both ends of the Mach-Zehnder interferometer, so that the sensing distance is prolonged; the optical fiber sensing system extracts the phase-modulated interference light signal and the back Rayleigh scattering light signal corresponding to the fault event when the fault event occurs; then, the extracted back Rayleigh scattering light signal is processed to obtain the intensity change information of the fault event, and the position of the fault event is demodulated; finally, the two-dimensional optical signal is sent into a pre-trained Swin Transformer network model to extract the time domain feature, the frequency domain feature and the spatial domain feature, and the type of the fault event is identified through a classifier.

According to an aspect of an embodiment, a hybrid optical amplifier may include an erbium doped fiber amplifier (EDFA) that includes multiple EDFA stages. The hybrid optical amplifier may also include a Raman amplifier inserted between two of the EDFA stages.

Embodiments of the present disclosure include an optical amplifier system that includes an erbium-doped fiber amplifier that includes a C-band EDFA configured to generate C-band light, and an L-band EDFA configured to generate L-band light. Raman amplifiers including fiber segments that may be pumped using reverse pump light.

Provided in the embodiments of the present disclosure is a method for adjusting the gain of a Raman amplifier. The method comprises: on the basis of a first preset adjustment target, adjusting a DRA-P pumping configuration (S202); on the basis of an amplifier performance parameter of a receiving end and a second preset adjustment target for the OSNR of the receiving end, determining a third preset adjustment target at a preset virtual midpoint position (S204); on the basis of the third preset adjustment target, adjusting a transmitting end configuration of a transmitting end (S206); and measuring an actual OSNR of the receiving end, and when the actual OSNR does not meet the second preset adjustment target, performing cyclical fine tuning on the DRA-P pumping configuration and / or the transmitting end configuration until the actual OSNR meets the second preset adjustment target (S208).

The application discloses a kind of gain adaptive 400G Raman amplifier control methods supporting remote adjustment, specifically relates to optical fiber communication and optical transmission network operation and maintenance control field, the method is generated target gain curve parameter set by remote control end, acquisition pump telemetry and 400G transmission quality index, stable feedback quantity is formed after sliding window preprocessing, abnormal point elimination replacement and filtering;Actual gain curve is calculated by collecting input / output power spectrum, construct the error vector of inclination error, ripple error and segmented differential error, link drift parameter is estimated on-line and based on step constraint sample updates pump response relationship;Parameter set and error vector are input into meta-learning pump inverse mapping model fine-tuning, output pump power, after upper and lower limit and step / rate constraint optimization, closed-loop regulation is issued;When transmission quality deterioration triggers safety threshold, it is rolled back to safe configuration and frozen update until recovery.

A method for computing a set of optimal amplification parameters for a span of a multi-span optical fiber network. Each span has an associated optical transmission fiber connected to associated amplifiers. The associated amplifiers include a forward Raman amplifier and at least one discrete amplifier. Gain and output power of the at least one discrete amplifier is respectively controlled independently. The method includes the steps of providing an analytical form of the signal power evolution along the corresponding span; computing a linear noise from amplifier noise figures and a non-linear noise generated in the corresponding span based on information about the span and the analytical form of the signal power evolution and using the computed linear noise and non-linear noise to compute the impact on the span performance; and computing a set of optimal amplification parameters for the corresponding span based on the impact on the span performance.

The present invention relates to the technical field of communications, and provides a Raman amplifier gain control method and a Raman optical fiber amplifier. The method comprises: inputting pump light of a corresponding wavelength into an optical fiber, and measuring out-of-band ASE power of the optical fiber in each preset frequency band; determining an actual gain coefficient of each preset frequency band on the basis of the out-of-band ASE power of each preset frequency band; matching the actual gain coefficient of each preset frequency band with a preset Raman gain coefficient of each preset frequency band, using an optical fiber corresponding to an actual gain coefficient having the highest similarity obtained by means of matching as a first optical fiber, and using an adjustment parameter of the first optical fiber to perform gain control of a Raman amplifier. The present invention, by means of deriving a Raman gain coefficient in reverse by using the out-of-band ASE power, can measure the Raman gain coefficient during the working process of the Raman amplifier, resolving the problem of it being difficult for a distributed amplifier to acquire a gain coefficient of optical fiber.