94 results about "Pulse broadening" patented technology

The application provides a communication device, a base station and a communication system. The communication device comprises a power divider, a coupler group and a multiplexer connected in sequence. The power divider is connected with the coupler group through at least two first lines. The power divider can divide light into at least two light beams. Each light beam is transmitted to the coupler group through a first line. Transmission of any two light beams in the corresponding first line has a phase difference and a time difference. The coupler group couples and interferes the received at least two light beams, and outputs at least two coupled light beams. Each coupled light beam enters the multiplexer through a second line. Transmission of any two coupled light beams in the corresponding second line has a time difference. The multiplexer can orthogonally combine the received coupled light beams. The communication device can perform dispersion compensation on the light to suppress pulse broadening, thereby reducing the bit error rate of optical signal transmission and reducing the power loss of the optical signal.

The invention discloses a photon-assisted microwave signal time-frequency amplitude-phase measurement system and method, and the system is characterized in that a pulse light source outputs a light pulse which enters an input end dispersive medium to complete pulse broadening, and then the light pulse enters an electro-optical modulation module; meanwhile, the power divider receives the microwave signal and divides the microwave signal into two paths to be input into an upper sub-modulator and a lower sub-modulator of the electro-optical modulation module so as to modulate optical pulses; a modulated optical signal output by the electro-optical modulation module passes through an output end dispersive medium to complete a time convolution process, then the output optical signal is divided into two paths through the optical coupling module, the two paths sequentially pass through the polarization controller, the polarization beam splitter, the photoelectric detector, the analog-to-digital converter and the digital signal processor, position information and amplitude information of an electric pulse are collected, and the position information and the amplitude information of the electric pulse are obtained. And obtaining time, amplitude, frequency and phase information of the microwave signal. The time, frequency, amplitude and phase information of the microwave signals can be measured at the same time, complex back-end processing is not needed, and the processing speed is high.

The invention relates to the technical field of multi-beam laser radar'low, small and slow 'target detection, in particular to a multi-channel TDC signal processing board card and a multi-beam laser radar signal processing system. According to the multichannel TDC signal processing board card, a pulse broadening circuit, a delay chain signal sampling circuit, a coding circuit, a synchronous coarse counting circuit and a data integration generation circuit are constructed based on an FPGA (Field Programmable Gate Array); the pulse broadening circuit is used for adjusting a starting moment and an ending moment of an input pulse to obtain a pulse broadening signal; the delay chain signal sampling circuit comprises a delay chain and a D trigger array; the pulse broadening signal is interpolated and delayed by a delay chain and then a thermometer code is generated by a D trigger array; the coding circuit is used for coding thermometer codes output by the D trigger array; and the synchronous coarse counter is used for triggering the data integration generation circuit, so that the data integration generation circuit integrates and outputs the coded data output by the coding circuit. According to the invention, the problem of synchronous acquisition and identification of the transmitting signal and the echo signal in the multi-beam laser radar is solved, and the time detection and measurement precision is improved.

This application discloses an assembly and adjustment device for a pulse broadening unit, comprising: a visible light source device, a pulse broadening unit, a phase delay element, a linear polarizer, and a reticle; the pulse broadening unit includes a beam splitter and a mirror assembly; the output beam from the visible light source device is incident on the beam splitter; the beam splitter splits the received output beam into a first reflected beam and a transmitted beam; the first reflected beam, after passing through a reflective lens assembly, is incident on the exit surface of the beam splitter, and after being reflected by the exit surface, it illuminates the reticle together with the transmitted beam; the linear polarizer is disposed in the optical path from which the transmitted beam exits, and the angle between its transmission direction and the polarization direction of the transmitted beam transmitted from the beam splitter satisfies the following condition: eliminating part of the energy of the transmitted beam; the phase delay element is disposed in the optical path before the first reflected beam is incident on the exit surface of the beam splitter, and is used to rotate the polarization direction of the first reflected beam by the same angle.

A laser device includes an oscillator outputting pulse laser light; an amplifier amplifying the pulse laser light; an optical pulse stretcher extending a pulse width of the pulse laser light; a beam divergence angle adjuster including an upstream lens arranged on an optical path of the pulse laser light, a downstream lens arranged downstream of the upstream lens, and an optical path length changing mechanism for changing an inter-lens optical path length between the upstream lens and the downstream lens; and a processor controlling the beam divergence angle adjuster and obtaining a repetition frequency or a duty of the pulse laser light, and to change, when the repetition frequency or the duty changes by a preset threshold or more, the inter-lens optical path length so that the beam divergence angle of the extended pulse laser light becomes small in accordance with the repetition frequency or the duty after the change.

The application discloses a kind of photonic auxiliary microwave signal time-frequency amplitude phase measurement system and method, pulse light source output light pulse in the system enters input end dispersion medium and completes pulse broadening, then enters electro-optic modulation module, simultaneously power divider receives microwave signal and it is divided two-way input electro-optic modulation module in upper and lower sub-modulator to modulate light pulse;The modulated light signal output by the electro-optic modulation module passes through output end dispersion medium, completes time convolution process, after this, output light signal will pass through optical coupling module and be divided into two paths, in turn pass through polarization controller, polarization beam splitter, photodetector, analog-digital converter, digital signal processor, the position information and amplitude information of electric pulse are collected, and the time, amplitude, frequency and phase information of microwave signal are obtained.The application can simultaneously measure the time, frequency, amplitude, phase information of microwave signal, and does not need complex post-processing, and processing speed is fast.

The application discloses a time-to-digital converter based on pulse stretching. The time-to-digital converter structure combines frequency multiplication delay locked loop, pulse stretching circuit and calibration circuit, guarantees high resolution, effectively increases the range of the time-to-digital converter, and can reduce the influence of PVT. The calibration circuit has simple structure, low calibration cost, and is suitable for the calibration of the pulse stretching circuit. In addition, the calibration algorithm for the static phase error of the frequency multiplication delay locked loop only needs to increase a 1bit counter, the additional circuit cost is very small, and the influence of the static phase error of the frequency multiplication delay locked loop can be overcome.

The invention relates to the technical field of microscopic imaging, and particularly provides a stimulated Raman scattering microscopic imaging system capable of simultaneously scanning double Raman frequency shift spectrums, which comprises a laser light source driving and modulating unit and a signal detecting and data processing unit, the laser light source driving and modulating unit comprises a dual-channel laser synchronous excitation module, a light beam polarization regulation and power distribution module, a pulse broadening and spectrum focusing module, a dual-channel dual-phase modulation module, a common-path different-time dual-frequency difference module and a laser scanning and telecentric focusing module; and the signal detection and data processing unit comprises a dual-channel orthogonal demodulation module and a scanning driving and signal synchronous acquisition module. Compared with the prior art, the dual-Raman frequency shift spectrum scanning stimulated Raman microimaging device has the advantages that dual-Raman frequency shift spectrum scanning stimulated Raman microimaging with higher acquisition speed, high resolution and wide spectrum coverage range is realized, and the problem of long time consumption for acquiring the complete spectrum of the to-be-tested sample by the traditional single-frequency resonance spectrum scanning stimulated Raman microimaging is solved.

This laser device is provided with: a laser oscillator which includes an optical resonator and a pair of electrodes for generating discharge by applying a voltage to a laser gas, and which outputs a first pulsed laser light; a first optical pulse stretcher that transmits a portion of the first pulse laser light, surrounds the other portion of the first pulse laser light by one circle, and outputs a first transmitted light and a first one-circle surrounding light, which have a first shift amount and spatially overlap a portion of the first transmitted light and the first one-circle surrounding light, thereby outputting a second pulse laser light in which the pulse time width of the first pulse laser light has been expanded; and a second optical pulse stretcher that transmits a part of the second pulse laser light, surrounds the other part of the second pulse laser light by one circle, and outputs second transmitted light and second one-circle surrounding light that have a second offset amount different from the first offset amount and spatially overlap a part of the second transmitted light and a part of the second one-circle surrounding light. As a result, a third pulse laser beam having an extended pulse time width of the second pulse laser beam is output.

The application discloses a ytterbium-doped fiber mode-locked laser, which comprises a first pump source, a first regenerator, a second pump source and a second regenerator. The first regenerator comprises a first ytterbium-doped fiber and a pulse stretching device, and the second regenerator comprises an isolator, a pulse compression device, a spectrum stretching fiber and a band-pass filter. The design of the staggered band-pass filter is realized through the two regenerators, and the spectrum is widened due to the self-phase modulation effect; in addition, the energy input of the first pump source and the second pump source can realize the mode-locked pulse output. The application reduces the peak power by pulse stretching to reduce the nonlinear effect, realizes the generation of high-energy output pulses in the fiber mode-locked laser, and the interval between the pulse stretching device and the central wavelength of the band-pass filter can effectively prevent the noise and continuous component from oscillating, and improve the pulse quality.

The application provides a high-power multicolor terahertz radiation generation device based on beat laser accumulation, which comprises an injector, an electron beam modulation system and a radiation system arranged in sequence; and a femtosecond laser system comprising a femtosecond laser, a first light splitting plate and a first mirror arranged in sequence and parallel to the electron beam transmission axis, the first light splitting plate splits the femtosecond Gaussian laser pulses from the femtosecond laser into first and second path femtosecond Gaussian lasers, the first light splitting plate, a pulse broadening system and the injector are arranged in sequence, and the first mirror, a laser accumulation system and the electron beam modulation system are arranged in sequence; the laser accumulation system generates beat accumulation laser with multiple terahertz cycles after receiving the second path femtosecond Gaussian laser. The device of the application can realize the center frequency of the multicolor terahertz radiation being adjustable, the number of the multicolor being variable, the frequency and time interval being controllable, the layout being simple, the tunability being strong and the flexibility being relatively high.

Apparatus for and method of aligning optical components such as beam splitters in an optical pulse stretcher in which a landing spot of a beam which has traversed a portion of the optical beam splitter and a coincident landing spot of a beam split from a retroreflected input beam are made to align on a target spot. Also disclosed is an apparatus and method for aligning the retroreflector to facilitate proper beam alignment. A fluorescent material may be used to render a beam landing spot visible.

The application relates to an underwater laser pulse time domain expansion measurement system and method, wherein the measurement system comprises a receiving lens for directly aiming at a pulse laser to be measured and receiving a laser beam output by the pulse laser to be measured; a laser processing unit connected with the receiving lens in an optical path to perform collimation, attenuation and light filtering processing on the laser beam; a high-speed photoelectric detector connected with the laser processing unit in an optical path, used for collecting the processed laser beam and converting the laser pulse electrical signal W1; a data acquisition board electrically connected with the high-speed photoelectric detector, used for collecting the laser pulse electrical signal W1 and sending the laser pulse electrical signal W1 to an analysis processing unit; and the analysis processing unit receives the laser pulse electrical signal W1, calculates the pulse width of the laser pulse electrical signal W1, and calculates the time domain expansion of the laser beam according to a pulse expansion calculation method. The application realizes direct measurement of the time domain expansion of an underwater laser pulse, and improves the measurement accuracy.

The invention provides a femtosecond laser pulse compression system with a compact structure and an adjustable pulse width, and relates to the technical field of femtosecond lasers, the system sequentially comprises a seed source, a pulse stretcher, an amplification chain and a pulse compression device along a light path, the pulse compression device comprises a polarization beam splitting unit, an electro-optical polarization modulation unit, a single compression grating and a light path turn-back unit; wherein the polarization beam splitting unit, the electro-optical polarization modulation unit, the single compression grating and the light path turn-back unit jointly form a multi-channel folding compression light path; a voltage signal with a specific time sequence is applied to the electro-optical polarization modulation unit, and the polarization state of a light beam is dynamically switched, so that the light beam is selectively controlled to complete back-and-forth transmission of a preset number of times in a multi-channel folding compression light path in different polarization states, and the compression ratio of laser pulses and the width of output pulses are continuously adjusted. On the premise that large-spread-width matching is guaranteed, the system is extremely compact, and the pulse width is continuously and flexibly adjusted in an electric control mode.

The application provides a method and device for intra-channel and inter-channel nonlinear joint compensation of a WDM system based on an improved LDBP and electronic equipment, and belongs to the technical field of optical fiber communication. The method compensates dispersion by using a linear filter in the time domain, the corresponding network structure is designed as one-dimensional convolution, and the pulse broadening effect is combined in the overlap reservation method, the physical model of nonlinear compensation is improved by considering the interference of intra-channel dispersion pulse broadening and the walk-off effect between channels, and the purpose of intra-channel and inter-channel nonlinear joint compensation is achieved. The application fully utilizes the random interaction between inherent dispersion and nonlinearity in the optical fiber communication system to compensate the phase shift caused by the nonlinear effect, can effectively equalize the nonlinear distortion of the signal under the condition of controlling the calculation complexity and reducing the implementation cost, and is expected to play a better role in the long-distance transmission of the large-capacity WDM system.

The invention belongs to the technical field of semiconductors, and particularly relates to an APD chip with an isolation groove and a preparation method of the APD chip. The APD chip provided by the invention comprises a first insulating layer arranged on the upper surface of a cap layer except a photosensitive region; the isolation groove at least simultaneously penetrates through the first insulating layer, the non-photosensitive area of the cap layer, the charge layer and the absorption layer, and the isolation groove surrounds the periphery of the photosensitive area. The isolation groove is arranged around the periphery of the photosensitive area, and the depth of the isolation groove is controlled, so that when light irradiates the passivation area, the APD chip of the detector does not generate a signal or the signal is very small due to the isolation effect of the isolation groove, and laser radar pulse broadening can be effectively inhibited. Therefore, the cost is reduced, and the problem of pulse broadening of the laser radar is solved.

A pulse stretcher includes a beam splitter splitting pulse laser light into two beams of pulse laser light, first concave mirrors arranged side by side in a predetermined direction, and second concave mirrors arranged side by side in the predetermined direction as having the same number as the first concave mirrors and facing the first concave mirrors, respectively. One beam of pulse laser light split by the beam splitter travels to one first concave mirror among the first concave mirrors and is reflected alternately by the first concave mirrors and the second concave mirrors 12 times or more as even number times to return to the beam splitter. A number of overlapping of the one beam at each of concentration points where at least part of the one beam of pulse laser light overlaps at beam waists of the one beam is two.

An optical pulse stretcher for stretching the pulse width of pulsed laser light, the optical pulse stretcher comprising: a polarizer that separates a component of incident pulsed laser light that has a specific polarization direction; delay optics including a plurality of mirrors for propagating the pulsed laser light that has been reflected by or transmitted through the polarizer; and a first Faraday rotator that includes a first magnet and a first Faraday material, is disposed on the optical path of the delay optics, and rotates the polarization direction of the pulsed laser light.

This invention discloses a device for real-time analysis of multidimensional information of spatiotemporally mode-locked pulses using an all-fiber structure, belonging to the field of ultrafast optics technology. It includes an all-fiber spatiotemporally mode-locked laser platform, a raw pulse beam profile measurement module, an optical circulator, a sub-pulse beam profile measurement module, and a dispersive Fourier transform and real-time spectral information detection module. Based on the generalized multimode nonlinear Schrödinger equation, this invention constructs a theoretical model of the spatiotemporally mode-locked laser, explores the multidimensional parameter coupling mechanism during spatiotemporal mode-locking, clarifies the mapping relationship between modes and frequencies, and provides a theoretical basis and method for high-precision mode differentiation and multidimensional real-time information extraction. This invention aims to rationally design the parameters of each fiber grating according to the spectral width and temporal interval of the spatiotemporally mode-locked pulse, reflecting more sub-pulses while ensuring that the pulse temporal domains do not overlap, achieving high-precision spatial mode resolution, and maximizing pulse broadening to obtain high-resolution real-time spectral information.

The present invention belongs to the field of laser ranging, and specifically relates to an absolute distance measurement method and device based on optical frequency comb chirped pulse interferometry. The method comprises: using an optical frequency comb to generate and split pulsed lasers; using one of the beams as signal light to generate reference light and measurement light, with a time delay between the two corresponding to the absolute distance to be measured; widening the other beam as local oscillator light, which interferes with the reference light and measurement light, respectively, to generate two interference pulses; widening the two interference pulses, and using a high-speed photodetector and a high-speed oscilloscope to collect information about the widened two interference pulses in real time; wherein the pulse width of the local oscillator light satisfies that the reference light and measurement light can interfere with the local oscillator light at any position; and subtracting the spectral phases of the two sets of chirped pulse interference fringe information to calculate the absolute distance to be measured. The present invention can achieve rapid absolute distance measurement along the entire path without blind spots.

A laser apparatus includes an oscillator configured to output a pulse laser beam, a random phase plate disposed in an optical path of the pulse laser beam, and an optical pulse stretcher disposed in the optical path of the pulse laser beam that has passed through the random phase plate and configured to stretch a pulse time width of the pulse laser beam by transmitting part of the pulse laser beam, making the other part circulate at least once through a delay optical path, and outputting transmitted light and circulating light.

The present invention discloses a multi-channel depth sounding waveform decomposition method and system combined with morphological priors, the method comprising: collecting multiple groups of waveform data of shallow water channels and deep water channels; calculating the eigenvalues ​​of each group of waveform data and constructing an eigenvector matrix; standardizing the eigenvalues ​​of each dimension in the eigenvector matrix to obtain standardized data; considering a Gaussian kernel function, substituting the standardized data into a support vector machine algorithm to train a classification model, and selecting a pulse broadening coefficient z according to the classification model; based on the pulse broadening coefficient z, using a Gaussian kernel function to fit the water surface and water bottom; fitting the water surface and water bottom according to the Gaussian kernel function to obtain the echo position of the Gaussian function and calculate the water depth. The advantages of the present invention are: improving the efficiency, accuracy and stability of water depth measurement.

The invention discloses a preparation method of a small pulse broadening drift tube for ultrafast diagnosis and the pulse broadening drift tube thereof. The method comprises the following steps: 1) brazing a front shell and a rear shell, and carrying out indium filling, indium melting and indium turning operation on the front shell; 2) performing spot welding to obtain a first grid mesh assembly, a second grid mesh assembly and a third grid mesh assembly; 3) preparing a substrate, a conductive film layer and a sealing film layer, and assembling to obtain a cathode input window; (4) sealing the metal anode flange, the frit ring and the optical fiber panel at high temperature, and plating a metal layer on the small surface of the optical fiber panel to prepare an anode assembly; (5) the first grid mesh assembly and the second grid mesh assembly are assembled on the front shell to obtain the front shell provided with the front assembly; and 6) preparing a cathode input window and a cathode at the rear end, degassing at high temperature, electronically brushing and sealing indium at high vacuum degree to obtain the small pulse broadening drift tube which can meet the requirements of the technical fields of nuclear detection, high-energy physics and the like on ultrafast diagnosis equipment.

A mid-infrared laser generation system based on dispersion-managed soliton bunch pulses. The system can achieve high-power, high-efficiency and high-proportion mid-infrared laser output, and has the advantages of an all-fiber configuration, a compact structure and a high power proportion in a longer-wavelength region of a mid-infrared spectrum. A pulsed fiber laser device generates a nanosecond pulse laser in a 1.5-micron band. A fiber pulse stretcher is made of a single-mode silica fiber, splits nanosecond pulses into a plurality of ultrafast soliton pulses by means of a nonlinear effect, and performs spectral energy conversion from 1.5 microns to 2.4 microns. A fiber laser amplifier further increases the output power of a stretched pulse laser and extends a spectrum to a 2.7-micron band, and also increases pulse energy beyond a 2.3-micron band. A fiber mode field adapter efficiently couples into a nonlinear fiber pulses generated in the fiber laser amplifier. The nonlinear fiber extends a laser to a mid-infrared 3-5-micron band, thereby achieving high-power, high-efficiency and high-proportion mid-infrared laser output.

The application discloses a LOS state detection circuit for an SFP optical module, which comprises an input inversion module, a signal conditioning and pulse expansion module and a threshold comparison and decision module connected in sequence. The input inversion module comprises a receiving original port link state indication signal, which is used for logical inversion of the original signal and enhancement of driving capacity. The signal conditioning module converts the data pulse stream output by a PHY chip into a smooth direct current voltage by using peak holding and RC expansion technology. The threshold comparison module intelligently judges whether the voltage represents valid signal activity through a hysteresis comparator, and finally outputs a hardware LOS signal which strictly conforms to the SFP MSA standard and is highly stable. The application realizes reliable optical signal loss detection in a full hardware mode, solves the problems of unstable output and easy misjudgment of a traditional scheme, and has the advantages of low cost, small area, fast response and high reliability, and is particularly suitable for integrated SFP optical module design.

The invention belongs to the field of laser emission devices, and provides a system and a method for adjusting and compensating high-order dispersion through broadening-compression coordination, and the method comprises the steps: calculating second-order dispersion and third-order dispersion introduced by a pulse amplifier; the introduced third-order dispersion is adjusted by changing the grating incidence angle in the pulse stretcher, so that the introduced third-order dispersion is counteracted with the total third-order dispersion of the system; according to the second-order dispersion change generated after the angle of the pulse stretcher is adjusted, a second-order dispersion value required to be provided by the pulse compressor is calculated, and the effective distance of the grating pair is adjusted for accurate compensation; and the angle of the pulse stretcher is corrected again according to the third-order dispersion feedback adjusted by the pulse compressor, and the steps are repeated until the total second-order dispersion and the third-order dispersion of the system approach to zero, so that near-transformation limit compression is realized. By adjusting the grating incident angle of the stretcher and the grating effective distance of the compressor, synchronous compensation of second-order and third-order dispersion in the ultrafast laser system is realized, and pulse output close to the transformation limit is obtained.

The application belongs to the field of laser emitting devices, and provides a system and method for compensating high-order dispersion through cooperative adjustment of stretching and compression, calculating second-order dispersion and third-order dispersion introduced by a pulse amplifier; adjusting the introduced third-order dispersion by changing the grating incident angle in a pulse stretcher, so that the third-order dispersion is offset with the total third-order dispersion of the system; calculating the second-order dispersion value required to be provided by the pulse compressor according to the second-order dispersion change generated after the angle adjustment of the pulse stretcher, and accurately compensating by adjusting the effective distance of the grating pair; feeding back the third-order dispersion of the pulse compressor after adjustment to correct the angle of the pulse stretcher again, and repeating the above steps until the total second-order dispersion and third-order dispersion of the system tend to be zero, so as to realize near transform limit compression. The application adjusts the grating incident angle of the stretcher and the effective distance of the grating of the compressor, so that the second-order dispersion and third-order dispersion in the ultrafast laser system are simultaneously compensated, and near transform limit pulse output is obtained.

The invention discloses a device for improving time uniformity of a framing camera based on curve pulses. The device comprises a cathode, an anode, a drift region, an MCP framing camera and a fluorescent screen which are arranged in sequence, the output end of a curve pulse generation circuit is connected with the initial end of the cathode, and the anode is grounded. The curve pulse generation circuit is composed of an IGBT driving module, a transformer coupling voltage reduction isolation module and a second-order Butterworth high-pass filtering module, and can generate curve pulses with non-linear change of the rising slope and apply the curve pulses to the cathode. Compared with the prior art, the single-path curve pulse is adopted to replace a traditional multi-pulse superposition scheme, the time uniformity of the pulse broadening framing camera is remarkably improved, and meanwhile the system structure is simplified.

The present application provides a kind of wideband pulse light source device with excellent performance, which solves the problem of SC light with seed light wavelength region remaining at high intensity. The light from the pulse laser source (1) is made to generate nonlinear effect by the nonlinear element (2) to generate supercontinuum light, and the light of the oscillation wavelength of the residual pulse laser source (1) is attenuated when being split by the dichroic mirror (32). The split light is pulse stretched by the optical fiber (41), and is multiplexed by the multiplexing element (33) to irradiate the object (S). The light transmitted through the object (S) is received by the light receiver (6), and the output signal thereof is converted into a spectrum by the operation unit (7).

This invention discloses a multi-stage cascaded laser frequency doubling device, belonging to the field of laser frequency doubling technology. It includes a front-end frequency doubling module and at least one cascaded frequency doubling module arranged sequentially along the optical path. The cascaded frequency doubling module includes a second-harmonic crystal, a third-harmonic crystal, a beam splitter, a delay adjustment device, and a beam combiner. The front-end frequency doubling module, beam splitter, second-harmonic crystal, beam combiner, and third-harmonic crystal are connected sequentially. By extending the multi-stage continuous cascaded crystal architecture, the long crystal is split into a sequence of thin frequency doubling crystals, suppressing time drift and pulse broadening. Each stage is equipped with a multi-band fully transparent film system to reduce dispersion. Furthermore, a beam splitting and beam combining bypass and dynamic time delay compensation are designed to achieve precise spatiotemporal beam combining of ultraviolet light, enabling femtosecond lasers to possess both high efficiency, low broadening, and excellent pulse quality.