1624 results about "Wavelength-division multiplexing" patented technology

The invention relates to the technical field of optical fiber frequency transmission, in particular to a distributed optical fiber optical frequency transmission method and system.The distributed optical fiber optical frequency transmission system is composed of a sending end and a plurality of receiving ends which are connected through an optical fiber link. An optical signal transmission module of a sending end divides laser generated by a laser into reference light and modulated light, the modulated light is transmitted to a receiving end after being subjected to positive frequency shift and wavelength division multiplexing, and return light is received at the same time. The signal processing module performs beat frequency processing on the reference light and the return light to obtain a radio frequency signal, performs phase processing to obtain an instantaneous frequency value, and modulates and converts the instantaneous frequency value into an optical signal through the optical transmitter. And the optical modulator module at the receiving end demodulates the modulated optical signal to obtain an instantaneous frequency value, and drives the modulator at the receiving end by using the frequency value to obtain a final optical frequency signal. According to the system, distributed high-precision optical frequency transmission is realized.

The invention discloses an optical cable topology visualization monitoring analysis system and method, and relates to the technical field of optical cable monitoring. According to the optical cable topology visual monitoring analysis system and method, the complex dependency relationship between optical cable network equipment is accurately captured by using the graph neural network, and the wavelength division multiplexing, OTDR test and optical power measurement technologies are fused, so that online monitoring without interrupting service communication is realized, the real-time performance and efficiency of monitoring are improved, the positioning precision of optical cable broken fibers can be improved, and the optical cable topology visual monitoring analysis system and method are suitable for popularization and application. Through new and old OTDR curve comparison and big data analysis, optical fiber aging and degradation trends are pre-judged in advance, accurate active operation and maintenance are realized, the probability of optical cable fault occurrence is reduced, the reliability and stability of a network are improved, and by cooperating with visual display of a complex power grid optical cable map, the method has the advantages of high accuracy and high reliability. The topological structure and the geographic position of the optical cable are visually displayed by fusing multiple levels, clear visual information is provided for operation and maintenance personnel, and management and decision making are facilitated.

The invention relates to an all-fiber sub-hundred femtosecond laser based on an SESAM. The all-fiber sub-hundred femtosecond laser comprises the SESAM, a wavelength division multiplexer, a pumping source, a pumping protector, a gain fiber, a chirp fiber bragg grating, an isolator, a reflector, a compression unit and an autocorrelator. According to the invention, the chirp fiber bragg grating with the dispersion amount of 0.115 ps / nm is adopted to compensate positive dispersion in the cavity, so that mode-locked pulse with the spectral width of 23nm is realized. A transmission-type diffraction grating pair is adopted, the pulse width is compressed to 88fs, and the maximum spectral width 27nm is obtained under the dispersion of 0.00087 ps2 in a near-zero cavity. The condition that the optimal spectral bandwidth of the optimal seed source pulse based on the optical fiber chirped pulse amplification laser should be larger than 15 nm is met, and the compression pulse distortion of the amplifier is reduced. By adopting the linear cavity, the SESAM is adhered to the surface of the single-mode optical fiber patch cord for starting mode locking, so that an all-optical-fiber structure of the system is realized, and the single-mode optical fiber patch cord is suitable for industrial integrated application.

The invention discloses a transmit-receive isolation system, and relates to the technical field of laser communication, a circulator of the transmit-receive isolation system comprises a first port, a second port and a third port, the first port is provided with a transmit-receive antenna, a light path from the first port to the second port is unidirectionally conducted, and a light path from the third port to the first port is unidirectionally conducted; the transceiving antenna is arranged at the first port; the signal processing module comprises a receiving end and a transmitting end; the first isolator is arranged between the second port and the receiving end, is in optical fiber connection with the second port and the receiving end, and is used for transmitting a remote optical signal in a one-way manner; the second isolator is arranged between the third port and the transmitting end, is in optical fiber connection with the third port and the transmitting end, and is used for transmitting a local optical signal in a one-way manner; according to the technical scheme of the invention, the invention provides the transmit-receive isolation system which is not limited by spatial light path arrangement.

The invention discloses a multi-core-particle optical matrix calculation framework, which is characterized in that a block matrix is adopted to decompose a large-scale optical matrix calculation chip into a plurality of small-scale optical matrix calculation core particles, and active and passive separation is adopted to decompose the optical matrix calculation chip into modulator array core particles, detector array core particles and optical matrix calculation core particles. Decomposing the M * N matrix A into m * n p * q matrixes Aij; an input N-dimensional vector X is decomposed into n-channel q-dimensional vectors Xj, and an output M-dimensional vector Y is decomposed into m p-dimensional vectors Yi. Input light passes through the n modulator array core particles to form n channel q-dimensional vectors, m * n q-dimensional vectors are formed after m beam splitting copying, the m * n q-dimensional vectors are input into the m * n optical matrix calculation core particles respectively and multiplied by Aij to obtain m * n p-dimensional vectors, m p-dimensional vectors are obtained after the light of the n channels passes through n channel multiplexing (wavelength division multiplexing, polarization multiplexing, mode multiplexing and the like and multi-dimensional multiplexing), and m * n p-dimensional vectors are obtained. And then detection is carried out, and large-scale matrix-vector multiplication calculation Y = AX is realized.

The invention discloses an optical interconnection system on an optical chip and the optical chip, relates to the technical field of communication, and aims to solve the technical problem of low system data capacity in the wavelength division multiplexing technology in the prior art. The system comprises a micro-ring modulation device, a polarization combiner and a demultiplexer, the output end of the micro-ring modulation device is connected with the input end of the polarization combiner; the input end of the demultiplexer is connected with the output end of the polarization combiner; the micro-ring modulation device is used for performing signal modulation on TE0 polarized light and TM0 polarized light in the light source; the polarization combiner is used for combining the TE0 polarized light and the TM0 polarized light output by the micro-ring modulation device and outputting combined light; and the demultiplexer is used for decomposing the combined light into signals corresponding to a plurality of wavelengths. By combining the polarization multiplexing technology and the wavelength division multiplexing technology, the number of multiplexing channels of the optical interconnection system is multiplied, and the data capacity of the optical interconnection system is improved.

The invention provides a stimulated Brillouin spectrum analysis device and method.The device comprises an optical circulator, a stimulated Brillouin medium, a probe light source, a double-sideband IQ modulator, an optical isolator, a dense wavelength division multiplexer, an up-down frequency conversion detector and a data acquisition board card, and light to be detected is injected into the stimulated Brillouin medium through the optical circulator; probe light enters a stimulated Brillouin medium after being modulated by a double-sideband IQ modulator, the modulated probe light and to-be-detected light generate characteristic frequency signals distributed on the two sides of the probe light frequency based on the stimulated Brillouin effect, stimulated Brillouin complex gain is calculated by demodulating light signals collected by an up-down frequency conversion detector, and the stimulated Brillouin complex gain is obtained. And the to-be-measured light information is obtained through inversion. By means of the scheme, high-resolution spectral analysis without scanning can be achieved, dependence on Brillouin frequency deviation in the optical fiber is eliminated, and the real-time performance of stimulated Brillouin spectral analysis is improved.

The invention discloses a wavelength division multiplexing-based all-fiber mirror image frequency sweeping interference distance measuring device and method, and relates to the technical field of absolute distance measurement. The objective of the invention is to solve the technical problems in the prior art that frequency spectrum aliasing, frequency sweep nonlinearity, Doppler effect and dispersion mismatch occur in frequency sweep interference measurement, and the measurement precision, the measurement efficiency and the reliability of an all-fiber mirror image frequency sweep interference ranging system cannot be ensured. According to the technical scheme provided by the invention, the wavelength division multiplexing-based all-fiber mirror image frequency sweeping interference distance measuring device comprises a laser unit used for outputting frequency sweeping light; the measurement interferometer light path is used for generating a measurement signal according to the sweep frequency light; the auxiliary interferometer light path is used for generating an auxiliary signal according to the sweep frequency light; the gas chamber calibration light path is used for carrying out auxiliary interferometer light path calibration according to the sweep frequency light; and the data acquisition and processing module is used for obtaining a distance measurement result according to the measurement signal, the auxiliary signal and the calibration signal. The method is applied to the work of all-fiber mirror image frequency sweeping interference distance measurement.

Coherent wavelength division multiplexing is provided using frequency comb sources for both the transmitter and the local oscillator (LO) in the receiver. The local oscillator is made phase coherent with the received multifrequency optical signal using two analog control loops. One of the control loops locks an optical frequency of the local oscillator to an optical frequency of the received frequency comb. The other control loop locks a microwave frequency of the local oscillator (i. e. LO the comb spacing) to the comb spacing of the received frequency comb. As a result, coherent detection is enabled in all channels with just two analog control loops. Control signals for the two loops can be derived from two of the received channels individually (asymmetric carrier recovery), or they can be derived from sum and difference signals from two of the received channels (symmetric carrier recovery).

The invention discloses a communication optical cable line fault rapid positioning system, which comprises optical time domain reflectometers and a remote monitoring center, and is characterized in that two optical time domain reflectometers with different optical pulse wavelengths are respectively connected to two ends of a communication optical cable line through wavelength division multiplexers on corresponding sides; the optical time domain reflectometer analyzes a reflected light signal received by the optical time domain reflectometer through a built-in intelligent algorithm, quickly calculates the position of a fault point and judges the type of the fault; the intelligent algorithm comprises a loss positioning algorithm, a reflection peak identification algorithm and a microbend loss analysis algorithm; the loss positioning algorithm is used for detecting the position of a fault point and distinguishing an optical fiber breakpoint and a loss type fault; the reflection peak recognition algorithm is used for detecting a fault point position; the microbend loss analysis algorithm is used for detecting and distinguishing microbend loss and other types of loss; the system has the advantages of being stable in detection system, good in detection effect, rapid in fault positioning and more accurate in detection result, and automatic detection, remote detection and remote monitoring and management of optical cable faults can be conveniently achieved.

A stream of photons from an optical source at a source wavelength are converted into entangled photon pairs via a spontaneous parametric down-conversion process. This produces time-synchronized signal and idler photon pairs which share a nominal wavelength, twice the source wavelength, a common polarization. The signal and idler individually have wavelengths that are equally offset above and below their nominal wavelength. The photons segregated into two paths based on wavelength via a wavelength division multiplexer. A phase modulator in the signal path alters the phase of the signal photon, while the idler photon's phase remains unchanged. By applying a modulation signal to the phase modulator, a quantum message is encoded on the photon pair. A multi-channel wavelength division multiplexer may be used to support multiple channels, each carrying signal-idler pairs conveying a quantum encoded message.

The invention discloses a high-tolerance synchronous dual-band pulse laser, and relates to the field of lasers, and the laser comprises a first resonant cavity and a second resonant cavity; the first resonant cavity comprises a first pumping source and an optical annular cavity formed by sequentially connecting a first wavelength division multiplexer, a first thulium-doped optical fiber, a first optical coupler, a first isolator, a second wavelength division multiplexer, a high-nonlinearity saturable absorber, a third wavelength division multiplexer and a first polarization controller; the second resonant cavity comprises a second pumping source and an optical annular cavity which is formed by sequentially connecting a fifth wavelength division multiplexer, a second erbium-doped fiber, a second optical coupler, a second wavelength division multiplexer, a high-nonlinearity saturable absorber, a third wavelength division multiplexer, an electric control adjustable delay line, a fourth wavelength division multiplexer, a second polarization controller and a second isolator, and the fifth wavelength division multiplexer, the second erbium-doped fiber, the second optical coupler, the high-nonlinearity saturable absorber, the third wavelength division multiplexer, the electric control adjustable delay line, the fourth wavelength division multiplexer, the second polarization controller and the second isolator; and the first optical coupler and the second optical coupler respectively output synchronization pulses in the wave bands of 2 microns and 1.5 microns. The device is compact in structure, low in manufacturing cost, convenient to operate and capable of covering the mid-infrared band of 2 microns.

The present invention discloses an L-band extended hybrid fiber amplifier, which belongs to the technical field of broadband fiber amplifiers. The system includes a first amplifying module and a second amplifying module; the first amplifying module is used to amplify the signal power of a conventional signal band; the second amplifying module is provided with an erbium-doped fiber, which is used to eliminate the backward ASE generated by the first amplifying module and amplify the signal power of an extended wavelength band. The present invention connects a section of highly-absorbent thulium-doped fiber to the front end of the first amplifying module including an erbium-doped fiber and a wavelength division multiplexer, and utilizes its absorption and emission characteristics in the C+L band to eliminate the backward 1.5μmASE generated in the system, thereby improving the L-band extended band amplification performance. The system of the present invention has a simple structure, high cost-effectiveness, and high efficiency, and at the same time meets the urgent demand for communication capacity of the current optical fiber communication system.

A visible-light communication and illumination array includes a substrate and plural surface-emitting superluminescent diodes, SLDs, distributed across the substrate. A first set of SLDs of the plural SLDs generates a first light beam having substantially a first wavelength, a second set of SLDs of the plural SLDs generates a second light beam having substantially a second wavelength, and a third set of SLDs of the plural SLDs generates a third light beam having substantially a third wavelength. The array further includes a controller configured to encode at least one of the first light beam, the second light beam and the third light beam to transmit information. A combination of the first light beam, the second light beam and the third light beam produces white light.

The invention provides a super lens, a super lens structure parameter determination method, device and equipment, optical imaging equipment, a storage medium and a program product. The super lens comprises a plurality of areas. Any region comprises a plurality of nano fins; wherein at least part of the area is used for focusing incident light with different wavelengths. The super lens is divided into a plurality of areas, and each area can form a super lens for focusing incident light with different wavelengths, so that wavelength division multiplexing is realized, and compared with a conventional geometrical optical lens for realizing wavelength division multiplexing, the super lens disclosed by the invention has the advantages of small volume and high integration level.

The invention discloses a wavelength demodulation system for wavelength division multiplexing based on a microring resonator, comprising a microring resonator chip, a modulation signal generating circuit, a photoelectric signal conversion circuit and a frequency mixing filter circuit; the modulation signal generating circuit generates a sinusoidal oscillation modulation signal with a DC bias, and transmits it to the microring resonator chip and the frequency mixing filter circuit; the microring resonator chip converts input optical signals of different wavelengths into optical signals related to the wavelength, and transmits them to the photoelectric signal conversion circuit; the photoelectric signal conversion circuit converts the optical signal output by the microring resonator chip into an electrical signal, and transmits it to the frequency mixing filter circuit after amplification, and the frequency mixing filter circuit realizes the mixing and filtering of the sinusoidal oscillation modulation signal transmitted by the modulation signal generating circuit and the converted electrical signal, and outputs the demodulated voltage signal. The demodulation system disclosed by the invention can demodulate the sensor reflection signal based on a wide-spectrum light source, has low cost and small size, and can realize large-scale multiplexing.

A system architecture is described that allows mapping of different RF-wave directions (e.g., Angles of Arrival or “AoA-s”) to different optical-carrier wavelengths. Such mapping enables the transmission of all information captured by a phased array, including spatial information of the incoming RF waves, using a single optical fiber.

The utility model discloses an on-chip integrated wavelength division multiplexer and a photon integrated circuit chip, the wavelength division multiplexer comprises a polarization compatible flat-topped wavelength division multiplexing structure, the flat-topped wavelength division multiplexing structure is provided with a first input waveguide group, a second input waveguide group and an output waveguide, the flat-topped wavelength division multiplexing structure performs odd-even grouping on the configured central wavelengths of the first input waveguide group and the second input waveguide group, and optical signals in different groups are respectively input into the wavelength division multiplexer in different polarization states; and on the basis of a single polarization compatible flat-topped wavelength division multiplexing structure, two groups of multi-path optical signals with different wavelengths in different polarization states are multiplexed into one path of multi-wavelength-polarization multiplexing light, so that signal crosstalk between adjacent channels is reduced, the structural complexity and size of the wavelength division multiplexer are simplified, and the integration level of a photon integrated circuit chip is improved.

The invention belongs to the technical field of quantum information, and particularly relates to a quantum entanglement and classical signal common-fiber transmission device based on a hollow-core optical fiber. According to the device, the characteristics of low loss and weak non-linear effect of the hollow-core optical fiber are utilized, the quantum entanglement two-photon pair and the classical optical signal are transmitted in the hollow-core optical fiber in a co-fiber mode through the wavelength division multiplexing technology and the polarization optimization strategy, the system can tolerate the classical signal with the higher communication rate, and the lower quantum signal bit error rate is allowed. The quantum entanglement and classical signal common-fiber transmission device designed through the method can be widely applied to the fields of quantum key distribution, quantum teleportation, quantum clock synchronization, distributed quantum calculation and the like compatible with a classical optical fiber communication system.

The invention discloses a power cable monitoring system and method based on single-core optical fiber multi-parameter sensing. The monitoring system comprises a laser, a first optical fiber coupler, an acousto-optic modulation unit, an optical fiber circulator, a distributed sensing optical fiber, a power cable, a wavelength division multiplexer, a second optical fiber coupler and a data acquisition monitoring unit. When the power cable to be detected is subjected to temperature change and vibration change, the temperature value of the power cable can be obtained by demodulating Raman scattering light data in backscattering light of the distributed sensing optical fiber, and Rayleigh scattering light in the backscattering light and local laser are subjected to interference frequency mixing to obtain a beat frequency signal; and the beat frequency signal is demodulated to obtain a vibration signal of the power cable. Based on the Raman scattering effect and the Rayleigh scattering effect, the temperature and vibration signals of the power cable can be detected at the same time only through one single-core optical fiber, and the method has the advantages of being high in signal-to-noise ratio, low in cost, easy and convenient to operate and the like.

The invention relates to the technical field of optical fiber transmission, and discloses a bidirectional optical fiber transmission system. Comprising a first wavelength division multiplexing / demultiplexing device, a second wavelength division multiplexing / demultiplexing device, a first power amplifier, a second power amplifier, a first preamplifier, a second preamplifier, a first optical fiber switching module, a second optical fiber switching module, a first filter, a second filter, a third filter and a fourth filter. The first optical fiber switching module and the second optical fiber switching module are provided with a first optical fiber or a second optical fiber for transmitting optical signals; according to the technical scheme, automatic switching to the standby optical fiber link is supported when the single optical fiber link fails or the performance is reduced, shunting and combining of wave band signals are achieved through the filter, and the stability and the anti-interference capability of transmission signals are ensured.

The invention provides a high-speed large-capacity intermediate infrared laser communication method and system based on an integrated waveguide, and is mainly used for solving the problems that when an existing space laser communication system adopts intermediate infrared band transmission, a frequency conversion scheme based on a block material is poor in phase matching, large in size, low in conversion efficiency, low in cost and the like. And the actual requirements of high-speed and large-capacity communication are difficult to meet. According to the high-speed large-capacity mid-infrared laser communication method based on the integrated waveguide, the first integrated waveguide is adopted to realize conversion from a near-infrared band to a mid-infrared band frequency comb, the wavelength division multiplexing technology is combined to maximize the channel capacity, and then the second integrated waveguide is adopted to restore a near-infrared band optical signal. The problems of insufficient capacity, generation of attenuation and loss, low rate and the like when near-infrared band optical signals are transmitted in an atmospheric channel are avoided, space laser communication with the rate of Tbps magnitude is realized, an optical field can be restrained in a micro-nano waveguide structure to the greatest extent, and the frequency conversion efficiency is improved.

The utility model discloses a high-order transverse mode controllable space-time mode locking all-fiber laser, which relates to the field of fiber lasers and comprises an annular laser system and a feedback system. The ring laser system comprises a laser diode pumping source, a wavelength division multiplexer, a gain fiber, a high-order transverse mode generation module, a multi-mode output coupler, a saturable absorber, a polarization controller, an isolator and an out-of-cavity coupler. The feedback control system comprises an image acquisition module, an image processing module and a feedback control circuit. Space-time mode locking is achieved based on the all-fiber saturable absorber, and the device has the advantages of being simple in structure, small in environmental influence, good in stability and the like. By inserting the multi-core multimode optical fiber and the conical multimode optical fiber into the all-fiber mode-locked laser, excitation of a high-order transverse mode and screening of the high-order transverse mode are effectively achieved. By externally connecting a feedback control system, the high-order transverse mode output by the laser is selected, and the space-time mode-locked all-fiber laser with controllable output high-order transverse mode is effectively realized.

An electro-optic receiver includes a bus optical waveguide and a plurality of wavelength division multiplexing (WDM) receiver slices positioned along the bus optical waveguide. Each of the plurality of WDM receiver slices includes a WDM element optically coupled to the bus optical waveguide, a photodetector, and a receiver circuit. The photodetector is optically connected to the WDM element by both a first optical connection and a second optical connection. The WDM element conveys a first component of input light through the first optical connection to the photodetector, and a second component of input light through the second optical connection to the photodetector, where first and second components of input light travel in opposite directions through the bus optical waveguide. The receiver circuit generates an electrical data signal from photocurrents received from the photodetector.

The invention belongs to the technical field of optical fiber sensing, and discloses a high-speed Fabry-Perot signal demodulation method and system based on a sparse spectrum. The method comprises the following steps: selecting a cavity length range of a Fabry-Perot cavity, and generating a cavity length sequence; repeating simulation to obtain reflection spectrums of the Fabry-Perot cavity under all cavity lengths in the cavity length sequence; adding noise to the reflection spectrum to obtain an analog acquisition spectrum; selecting a channel according to the output wavelength of the wavelength division multiplexer, obtaining a sparse spectrum, and constructing a data set; training the neural network model through the data of the data set; after training is completed, a reflection signal of the Fabry-Perot cavity is obtained through a wavelength division multiplexer and a photoelectric detector array and converted into a sparse spectrum; and inputting the obtained sparse spectrum into the neural network model to obtain the cavity length of the optical fiber Fabry-Perot sensor and realize Fabry-Perot signal demodulation. The demodulation rate and the monitoring efficiency of the optical fiber Fabry-Perot sensor are improved, and an efficient and reliable remote monitoring solution is provided for multiple fields.

The invention provides a wavelength division multiplexing / demultiplexing system based on micro-ring structure and phase change material modulation and a preparation method thereof, and belongs to the field of optical coupling devices. The wavelength division multiplexing / demultiplexing system comprises a substrate and a buried oxide layer which are stacked, and n (n is a positive integer greater than or equal to 2) micro-ring units and an upper cladding which are positioned on the upper surface of the buried oxide layer. And the upper cladding covers the n micro-ring units and is in contact with the buried oxide layer. Each micro-ring unit comprises a straight-through waveguide and at least one micro-ring waveguide. And the n micro-ring units are connected into a whole through the straight waveguide. The micro-ring waveguide includes a first ring waveguide and a second ring waveguide over the first ring waveguide. The second annular waveguide is made of a phase change material, and a fourth distance exists between the second annular waveguide and the first annular waveguide. The micro-ring waveguides are arranged at intervals along the extension direction of the straight waveguide. A first distance exists between the straight-through waveguide and the micro-ring waveguide. The wavelength division multiplexing / demultiplexing system has the properties of low energy consumption, low loss, non-volatility and the like.

The invention relates to a 3 [mu] m SOI process integration method for an on-chip beam forming and wavelength division multiplexing system. The method comprises the steps of silicon waveguide etching, PN ion implantation, germanium-silicon epitaxy, germanium-silicon waveguide etching, metal layer growth and the like. In order to solve the problem that the silicon PN doping annealing temperature is higher than the germanium-silicon PN doping annealing temperature, the germanium-silicon epitaxial etching postposition technological process is developed, and the non-selective epitaxy and reverse etching modes are used, so that the problem that a wafer is uneven after silicon etching doping is solved. The method has extremely high application value in large-scale silicon photon integration application, and can be used for manufacturing complex active photon chips integrated with modulators, detectors and the like.

The invention belongs to the technical field of optical communication, and particularly relates to a high-stability photo-generated millimeter wave system based on a phase-locked loop, which comprises a first laser, a second laser, an acousto-optic frequency shifter, a dense wavelength division multiplexer, an inner loop feedback control loop and an outer loop signal output branch, the inner loop feedback control loop comprises a phase modulator, an optical filter, a photoelectric detector, a frequency division arithmetic unit, a phase frequency detector, a loop filter, a voltage-controlled oscillator and a first power amplifier which are sequentially connected in series, and the output of the first power amplifier is connected with an acousto-optic frequency shifter; the inner loop feedback control loop further comprises a cesium atomic clock, a microwave source and a second power amplifier; wherein the cesium atomic clock is connected with the microwave source and the phase frequency detector, and the output of the microwave source is connected with the phase modulator after passing through the second power amplifier.

The invention discloses a laser radar range resolution improving device and method based on wavelength division multiplexing, and belongs to the field of laser radar system design and data processing.According to the wavelength division multiplexing principle, multi-wavelength laser signals are emitted, processed and output through a signal modulation module after wavelength division multiplexing, and then a plurality of linear frequency modulation signals are output; in a direct acquisition mode, heterodyne receiving is carried out on the demultiplexed signal, an imaging result of an equivalent large modulation bandwidth signal can be obtained through signal processing, and the method can be used for a laser radar system for high-precision distance measurement. Compared with a traditional single-wavelength laser radar structure, the limitation of the modulation bandwidth of an electro-optical modulator can be broken through, and the emission signal bandwidth is multiplied, so that the range resolution of the laser radar is greatly improved, and the imaging quality of a target object is better; meanwhile, the sampling rate requirement of each channel in a direct sampling mode can be reduced, and the problem that a high-bandwidth signal cannot be collected due to an AD rate bottleneck existing in a direct sampling condition is solved.

A DFB linear polarization single-frequency fiber laser based on the polarization traction effect comprises a polarization-maintaining single-axis fiber isolator, the input end of the polarization-maintaining single-axis fiber isolator is connected with the signal end of a polarization-maintaining wavelength division multiplexer, and the pumping end of the polarization-maintaining wavelength division multiplexer is connected with the output end of a single-mode pumping light source. A common end of the polarization-maintaining wavelength division multiplexer is connected with one end of the polarization-maintaining fiber bragg grating, the other end of the polarization-maintaining fiber bragg grating is connected with an output end of the phase-shift fiber bragg grating through the PZT phase modulator, and the phase-shift fiber bragg grating is inscribed on a gain fiber to form a DFB fiber laser resonant cavity and fixedly packaged in an automatic temperature control heat sink. The DFB fiber laser resonant cavity is connected with the input end of the photoelectric detector, and the photoelectric detector converts an idle end laser signal of the DFB fiber laser resonant cavity into an electric signal. The linear polarization single-frequency laser source with excellent performance, high linear polarization degree and high stability can be provided for the fields of fiber-optic gyroscopes, nonlinear frequency conversion, coherent polarization beam combination and the like.