23 results about "Raman amplification" patented technology

This invention discloses a multi-wavelength Brillouin and Raman random fiber laser based on tunable broadband Raman pumping, comprising a 1.5μm Brillouin pump, a 1.45μm tunable broadband Raman pump, a wavelength division multiplexer (WDM) I, and a passive fiber. The 1.45μm tunable broadband Raman pump includes a wavelength-tunable cascaded random Raman fiber laser, a WDM II, and a single-mode fiber I. The wavelength-tunable cascaded random Raman fiber laser is injected into the single-mode fiber I through the WDM II. This multi-wavelength Brillouin and Raman random fiber laser based on tunable broadband Raman pumping provides a 1.45μm tunable broadband Raman pump source by back-Raman amplification of the broadband seed light. Working together with the 1.5μm Brillouin pump, it can achieve ultra-wideband multi-wavelength random fiber laser output. By simultaneously tuning the output wavelengths of the Brillouin pump and the Raman pump, wavelength tuning of the broadband multi-wavelength random fiber laser can be achieved.

To provide an optical transmission device, an optical transmission system, and an optical transmission method that suppress an OSNR penalty due to return light.SOLUTION: An optical transmission device disposed at a fiber end of a single-core optical fiber and used when signal light is bidirectionally transmitted through the optical fiber, the optical transmission device comprising an optical transmitter configured to transmit first signal light in one direction belonging to the signal light, an optical receiver configured to receive second signal light in a reverse direction belonging to the signal light, and a controller configured to guide the first signal light transmitted from the optical transmitter to the optical fiber, An optical circulator configured to guide the second signal light from the optical fiber to the optical receiver; and a light source configured to output, to the optical fiber, excitation light that Raman-amplifies the second signal light to second optical power higher than first optical power of the first signal light.SELECTED DRAWING: Figure 2

The present invention provides an optical transmission system that can satisfy the XT required by the modulation method even if there is a difference in inter-core loss in the MCF. The optical transmission system of the present invention includes: a multicore optical fiber having a plurality of core regions, in which the loss is different between at least two cores; a front excitation light source and a combining section for causing Raman amplification excitation light in the same direction as the signal light to be incident on each core of the multicore optical fiber; a rear excitation light source and a combining section for causing Raman amplification excitation light in the opposite direction to the signal light to be incident on each core of the multicore optical fiber; characterized in that the intensity ratio of the front excitation light and the rear excitation light (the ratio of the power of the excitation light is set to a prescribed value) is controlled to reduce the variation in inter-core crosstalk (XT).

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 invention relates to the technical field of power equipment on-line monitoring and fault diagnosis, and discloses a GIL temperature distribution detection device based on double optical comb coding BOTDA, which comprises a GIL temperature sensing optical fiber, a double optical comb signal generation assembly, an optical transmission and detection assembly and an intelligent control and calculation system. The sensing optical fiber is attached to the surface of the GIL through a suspension type loose tube structure, and stress cross sensitivity is eliminated. The double-optical-comb assembly generates a pumping and detection optical comb loaded with random phase codes, and the peak-to-average power ratio is reduced to suppress modulation instability. The transmission assembly is matched with distributed Raman amplification to realize long-distance bidirectional injection, and optical downsampling is realized by using an optical comb beat frequency effect. And the control system executes closed-loop gain adjustment according to a comparison result of the detection power and a nonlinear threshold value, and calculates the temperature through space-time mapping. According to the invention, the contradiction between the signal-to-noise ratio and the nonlinear effect in long-distance sensing is solved, and high-precision and rapid GIL whole-line temperature monitoring is realized.

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.

The application discloses a kind of based on external cavity stimulated raman amplification laser radar light source, including continuous laser, laser pulse modulation module, first optical amplifier, optical coupling isolation module, pump light source, pump combiner.The application increases pump light source and pump combiner, so that the pulsed light source of laser radar atmospheric detection and the laser output by pump light source are co-propagating in the same path in atmosphere, can further amplify pulsed light source, improve signal-to-noise ratio, extend laser radar detection distance.The laser light source of the application is used for laser radar atmospheric detection, when transmitting in atmosphere, beam is not constrained by optical fiber, nonlinearity in atmosphere is very weak, the power of pump light source can be very large (up to hundreds of watts), and the output signal light signal is not affected by the nonlinearity of optical fiber transmission.

This invention relates to the field of laser technology, and particularly to a Raman laser that outputs 9.2μm far-infrared laser light. It includes a laser pump beam splitting module, a first-order Raman laser generation module, a difference-frequency seed light preparation module, a laser beam combining and tuning module, a second-order Raman amplification module, and a laser collimation and separation module arranged sequentially along the optical path. The laser pump beam splitting module is used to achieve beam splitting and control of the 1064nm laser; the first-order Raman laser generation module is used to generate a 1.9μm first-order Raman laser from hydrogen; the difference-frequency seed light preparation module is used for difference-frequency preparation of the 9.2μm Raman seed light; the laser beam combining and tuning module is used for spatiotemporal overlap and beam combining of the pump light and the seed light; the second-order Raman amplification module is used for Raman amplification of the 9.2μm laser; and the laser collimation and separation module is used for collimation and separation of the target laser output. This invention utilizes a difference-frequency method to generate wavelength-matched far-infrared Raman seed light, and performs Raman amplification to ultimately obtain a 9.2μm far-infrared Raman laser with high pulse energy and high peak power.

A wavelength converter includes: a first multiplexer that combines input signal light with wavelength-conversion excitation light; a second multiplexer that combines the signal light with Raman excitation light; a first nonlinear optical medium that generates wavelength-converted light of the signal light, based on a nonlinear optical effect; and a second nonlinear optical medium that amplifies wavelength-converted light of the signal light output from the first nonlinear optical medium. A wavelength of the Raman excitation light being a wavelength within an amplification band that allows Raman amplification of wavelength-converted light.

This invention provides a U-band high-energy square-wave pulsed Raman light source module. It first achieves initial stable amplification of the seed light through forward pumping with a 100-watt pump source, followed by high-energy main amplification through reverse pumping with a kilowatt-level pump source. Both stages of Raman amplification utilize highly nonlinear optical fibers as the gain medium to significantly enhance the stimulated Raman scattering effect, efficiently converting pump light energy into signal light and improving overall Raman gain and energy conversion efficiency. Simultaneously, it balances the stability of the amplification process with the integrity of the pulse waveform, thereby achieving a smooth, step-by-step amplification of the U-band pulsed seed light. Ultimately, it stably outputs high-energy U-band square-wave pulsed light with a single pulse energy ≥5μJ and a pulse width of 80–120ns, significantly improving the light source's output performance and better meeting the application requirements of long-distance fiber optic communication expansion and atmospheric methane remote sensing.

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.

This invention belongs to the field of optical fiber testing and sensing technology, specifically relating to a method for identifying faults and disturbances in few-mode optical fibers using Raman-enhanced time-domain reflectometry (TDDR). The method includes: signal transmission based on pulse coding and mode-selective excitation; signal-to-noise ratio enhancement based on distributed Raman amplification; mode demultiplexing and mode field detection; coded demodulation and reconstruction using a multi-mode few-mode optical TDDR; multi-dimensional fault identification based on mode-dependent loss and coupling characteristics; and multi-mode differential and high-precision positioning based on digital signal processing. This invention targets high-capacity communication and distributed sensing systems using few-mode fibers. It solves the problem of detecting weak inter-mode scattering signals by coordinating pulse coding gain and distributed Raman optical gain. Subsequently, it utilizes the unique mode-dependent loss and inter-mode energy transfer characteristics of few-mode fibers for joint decision-making, providing highly sensitive, multi-dimensional optical fiber link health monitoring capabilities. This method has great potential and application prospects in the operation and maintenance of next-generation space-multiplexed optical networks.

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.

An optical transmission apparatus is disposed at an end of a single-core optical fiber and is used when signal light is transmitted bidirectionally by the optical fiber. The optical transmission apparatus includes an optical transmitter that transmits a first signal light in one direction belonging to the signal light, an optical receiver that receives a second signal light in an opposite direction belonging to the signal light, an optical circulator that guides the first signal light transmitted from the optical transmitter to the optical fiber and guides the second signal light from the optical fiber to the optical receiver, and a light source that outputs, to the optical fiber, pump light for Raman-amplifying the second signal light to a second optical power higher than a first optical power of the first signal light.

An object of the present invention is to provide an optical transmission system capable of satisfying XT required by a modulation system even if there is an inter-core loss difference in an MCF.An optical transmission system of the present invention includes a multi-core optical fiber having a plurality of core regions and having different losses between at least two cores, a forward excitation light source and a multiplexing unit for allowing Raman amplification excitation light to be incident on each core of the multi-core optical fiber in the same direction as signal light, and a backward excitation light source and a multiplexing unit for allowing Raman amplification excitation light to be incident on each core of the multi-core optical fiber in a direction opposite to the signal light, wherein an intensity ratio of the forward excitation light to the backward excitation light is controlled (a ratio of power of excitation light is set to a predetermined value) such that crosstalk (XT) fluctuation between cores is reduced.

The application discloses a kind of big energy stimulated raman laser based on batten structure, belong to laser technology and nonlinear optics field.The laser includes pump source, shaping optical system, batten laser crystal, Q device, resonant cavity and amplification structure.The laser uses batten gain medium and raman crystal, realizes high-efficiency 1 μm pulse laser output by partial end face pumping and polarization double-pass amplification technology;Further utilize external cavity raman resonant cavity to generate stable stimulated raman seed light, and pass through multi-mirror regulation light path, so that seed light and pump light are in batten raman amplification crystal space synchronization, realize high-efficiency stimulated raman amplification.The application effectively solves the problem of poor heat dissipation and significant thermal effect of traditional rod structure, has the advantages of high heat dissipation efficiency, good beam quality, large output energy, strong stability, is suitable for atmospheric laser radar detection, photoelectric countermeasure, spectrum detection, medical treatment and industrial processing and other fields.

An optical signal amplification apparatus includes a power detection module, a pump control module, and a Raman amplification module. The power detection module is configured to detect power of each of a plurality of G wavelength channels in each of a plurality of N spatial dimensions, and send power configuration information to the pump control module. The pump control module is configured to output N channels of pump light, where each channel of pump light includes M pieces of split pump light of different wavelengths, and a proportion of each piece of split pump light in pump light of a corresponding wavelength is determined based on the power configuration information. The Raman amplification module is configured to perform Raman amplification on a space division multiplexed signal in all of the N spatial dimensions by using the N channels of pump light.

To appropriately control a gain of Raman amplification in each of a case where light is transmitted in all wavelength bands and a case where light is transmitted only in a part of wavelength bands among predetermined wavelength bands.SOLUTION: When the signal unit does not receive the optical signal of the first band among the plurality of bands, the control unit 14 controls the excitation light source 111 to output the excitation light having a power smaller than that when the optical signal of the first band is received or to stop the output of the excitation light. The excitation light source 111 is controlled so as to output the excitation light of power smaller than the power of the excitation light outputted when the optical signal of the first band is received, and the excitation light source 112 is controlled so as to output the excitation light of power larger than the power of the excitation light outputted when the optical signal of the first band is received.SELECTED DRAWING: Figure 2

An apparatus, system, and method for distributed Raman amplification of a multi-core fiber (MCF) are disclosed. An 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 apparatus also includes a coupler to couple the at least one combined depolarized optical light into the MCF. The combined depolarization optical Raman amplifies an optical signal in the MCF.

A Raman amplification system includes a backward-pumped Raman amplifier provided on an output side of a transmission line and a forward-pumped Raman amplifier provided on an input side of the transmission line, and amplifies a plurality of signal bands by using the backward-pumped Raman amplifier and the forward-pumped Raman amplifier. The backward-pumped Raman amplifier includes a power detector that detects power of at least a part of a signal band on a longest wavelength side among a plurality of signal bands. The forward-pumped Raman amplifier includes a second pumping light source that outputs second pumping light of a specific wavelength for amplifying a second signal band from a shorter wavelength side with highest efficiency among the plurality of signal bands and a second controller that controls the power of the second pumping light source based on a result obtained from the power detector.

The invention relates to an unmanned aerial vehicle image transmission system and method based on an optical fiber transmission architecture and private zero-delay coding, and the system comprises an image collection module, a private low-delay coding module and a light transmitting module which are disposed on an unmanned aerial vehicle, and a light receiving module, a decoding module and a display control interface which are disposed at a ground end. And the photoelectric composite mooring cable is integrated with the single-mode optical fiber and the power supply conductor. And the coding module sequentially executes blocking, lifting wavelet transform, adaptive quantization and parallel non-context adaptive binary arithmetic coding to generate a code stream suitable for optical fiber direct transmission, and the code stream is converted into an optical signal through the SFP + optical module to be transmitted in a single-mode optical fiber. Under the near-zero coding time delay (lt, 1ms), the code rate is reduced by about 70% compared with that of a bare code stream, and bandwidth is reserved for FEC, link monitoring and redundancy; and a long-distance link can be realized in combination with distributed Raman amplification, and cooperative work with mooring power supply and optical / wireless backup is realized.

The invention discloses a forward Raman nonlinear suppression amplification method for OAM optical communication, and relates to the technical field of nonlinear optics, OAM composite signals are separated into multiple groups of intrinsic signals according to spiral phase characteristics and radial distribution characteristics, corresponding gain coefficients are adjusted through an order gain algorithm according to cooperative attenuation characteristics of orders and moduli of an OAM mode, and the OAM optical communication is realized. Pre-amplification is carried out on each group of intrinsic signals; collecting and calculating the dispersion amount of each group of amplified intrinsic signals, mapping orders and moduli according to a modulation type time sequence model to generate a control vector, taking the control vector as a modulation constraint, deducing a predicted dispersion amount, and superposing the predicted dispersion amount with an actual dispersion amount to carry out dispersion pre-compensation; the method comprises the following steps: determining the number of pumping wavelengths, collecting transmission loss, calculating target Raman gain, distributing injection point power and pause duration to realize distributed Raman amplification, inhibiting FWM clutter by using random phase modulation, and sending the FWM clutter to a receiving end for processing and demodulation to realize stable long-distance OAM optical communication.

To provide a light source, a light source device, a light source driving method, a Raman amplifier, and a Raman amplification system using the same, in which RIN and ripple are suppressed at the same time.SOLUTION: A light source includes a seed light source that outputs incoherent seed light having a predetermined band, and a booster amplifier which is a semiconductor optical amplifier that optically amplifies the seed light input from the first facet and outputs the amplified light from the second facet, and in the booster amplifier, nL which is the product of the refractive index n and the tip length L is set such that the relative intensity noise (RIN) and ripple are simultaneously suppressed in the amplified light.SELECTED DRAWING: Figure 1