19 results about "Nonlinear fiber" patented technology

A light source includes a mode-locked laser; a beam splitter that branches the femtosecond optical pulse train; a CW solid-state laser; a first beam combiner that outputs one side of the femtosecond optical pulse train on the same axis; a secondary nonlinear optical element that outputs a difference frequency generation and conversion optical pulse train from either a continuous wave or a femtosecond optical pulse train; an amplifier that amplifies the difference frequency generation and conversion optical pulse train; a polarization-maintaining all normal dispersion high nonlinear fiber that converts the other femtosecond optical pulse train into a supercontinuum optical pulse train; a first dispersion medium that converts the supercontinuum optical pulse train into a pulse width that is approximately the same as the difference frequency generation and conversion optical pulse train; and a second beam combiner that multiplexes and outputs the difference frequency generation and conversion optical pulse train and the supercontinuum optical pulse train.

A spectral domain optical coherence tomography (OCT) system utilizes an electrowetting prism having four isolated electrodes and configured to deflect a light beam according to an actuating control signal applied to the electrodes. The control signal causes the light beam to laterally scan over a sample. The light beam is produced by a broad bandwidth laser and light from the sample and a reference path is provided to a spectrometer for analysis. The light source may be an all-normal-dispersion fiber laser seeding a gain-managed nonlinear fiber amplifier. The electrowetting prism is capable of scanning up to ±6°. The system is low power and operates at kHz speed.

The application belongs to the technical field of ultra-short pulse laser, and particularly relates to a nonlinear fiber loop and full positive dispersion pump protection type 8-shaped cavity and a laser. The nonlinear fiber loop comprises a first circulator provided with three ports, a second circulator provided with three ports and a beam combiner. The first port of the first circulator is used to connect the third port of a coupler, the second port of the first circulator is connected with the third port of the second circulator, and the third port of the first circulator is connected with the output end of the beam combiner. The first port of the second circulator is used to connect the fourth port of the coupler through a first gain fiber, the second port of the second circulator is connected with the signal end of the beam combiner, and the first input end of the beam combiner is connected with a first pump light source.

The utility model relates to the field of ultrafast lasers, and provides a tunable low-repetition-frequency optical fiber optical frequency comb light source. Comprising an all-polarization-maintaining ultrafast fiber laser seed source, a fiber pre-amplification stage module, a fiber main amplification stage module, a grating pair dispersion matching module, a super-continuum spectrum generation module and an f-2f self-reference detection module which are sequentially arranged along a light path. The full polarization-maintaining ultrafast fiber laser seed source is used for outputting continuously tunable signal light with low repetition frequency; the optical fiber pre-amplification stage module and the optical fiber main amplification stage module are used for carrying out self-similarity amplification and power amplification on the input signal light in sequence; the grating pair dispersion matching module is used for performing dispersion matching on the amplified signal light; the super-continuum spectrum generation module is used for coupling the signal light subjected to dispersion matching into a high-nonlinearity optical fiber to generate a super-continuum spectrum light source; and the f-2f self-reference detection module is used for measuring the super-continuum spectrum light source to obtain a light frequency comb with low repetition frequency.

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 present invention discloses a high-repetition-rate all-fiber ultrashort pulse laser, comprising: a pump source, a wavelength division multiplexer, an erbium-doped fiber, and a highly nonlinear fiber are connected in sequence by optical fibers downstream of the optical path of the pump source; a coupler is connected by an optical fiber downstream of the optical path of the highly nonlinear fiber; a mode-locking device is connected by an optical fiber downstream of the optical path of the coupler; the light inlet of a circulator is connected by an optical fiber downstream of the optical path of the mode-locking device; the first light outlet of the circulator is connected by an optical fiber along the optical path direction to a first fiber Bragg grating; the optical path downstream of the first fiber Bragg grating is connected by an optical fiber to a second fiber Bragg grating; a grating wavelength tuning device is connected to the second fiber Bragg grating; and the second light outlet of the circulator is connected by an optical fiber along the optical path direction to the light inlet of the wavelength division multiplexer. By means of the wavelength adjustment device, the present invention realizes the change of the center wavelength interval between the two gratings, and further realizes a high-repetition-rate ultrashort pulse laser with adjustable repetition frequency.

The invention discloses a melt electric writing nonlinear fiber printing accuracy evaluation method and system based on pixel superposition, and relates to the technical field of textile methods. The method comprises the following steps: image preprocessing: cutting, aligning and zooming an actual printing fiber pattern image to enable the actual printing fiber pattern image to be consistent with a starting point, a direction and a resolution of a target pattern image; smoothing the image, binarizing the image, and finally removing stray points; coincident pixel point calculation: after the printed fiber pattern is obtained, increasing the pixel width of the target pattern, and performing coincident pixel point calculation on the target pattern and the printed fiber pattern in the increasing process; and printing error calculation: calculating a printing error E by analyzing the change of the number of overlapped pixel points along with the increase of the width, and quantitatively reflecting the deviation between the printed fiber pattern and the target pattern. The method and system can evaluate the printing accuracy of nonlinear fibers.

The utility model discloses an ultraviolet optical fiber optical parametric oscillator based on tunable picosecond green light. The ultraviolet optical fiber optical parametric oscillator comprises a high-power wavelength and repetition frequency adjustable 1 [mu] m laser system, a high-power second harmonic generation device and an optical fiber optical parametric oscillator, the high-power wavelength and repetition frequency adjustable 1 [mu] m laser system comprises a mode-locked fiber laser, a pulse stretcher, an adjustable fiber filter, a fiber pre-amplifier, a fiber collimator and a solid amplifier. According to the utility model, the wavelength of ultraviolet laser can be flexibly adjusted; through a narrow-band filtering technology, the generation efficiency of the ultraviolet laser is improved; an optical parametric oscillator based on a nonlinear optical fiber is designed, a more compact resonant cavity structure is realized, the influence of a heat effect on system efficiency and stability is inhibited, and ultraviolet laser with an excellent light spot mode can be output; the dispersion parameter of the nonlinear optical fiber can be regulated and controlled, so that the phase matching condition of four-wave mixing is optimized, and the efficiency and wavelength tuning range of ultraviolet laser are further improved.

The invention discloses a tunable femtosecond soliton fiber laser, which belongs to the technical field of solid lasers and comprises a pumping source, a wavelength division multiplexer, a first focusing lens, a periodically poled nonlinear crystal, a second focusing lens, a positive dispersion high nonlinear fiber and an output coupler which are connected in sequence, and one output port of the output coupler is connected with the wavelength division multiplexer. According to the invention, only two focusing lenses are adopted to form the cavity, and the length ratio of the cavity is small; the two lenses are matched with the positive-dispersion high-nonlinearity optical fiber, during wavelength tuning, the focusing lens does not need to be translated continuously, intracavity dispersion management is achieved directly by adjusting the length of the optical fiber, then chirp-free pulses are output, 1.7-2.3 [mu] m tunable femtosecond soliton source output with high stability and high integration is achieved, the problem of a near-infrared femtosecond seed source can be solved, and the near-infrared femtosecond soliton source can be used as a near-infrared femtosecond soliton source. And the problem of expensive and complex system design caused by careful control of intra-cavity dispersion and cavity length required by stable operation of the femtosecond OPO can be solved.

The invention provides a code conversion system and method based on a coherent light orthogonal frequency division multiplexing system, and the system comprises a first low-loss band-pass filter which is used for processing an electric signal obtained after 16QAM signal conversion and then transmitting the processed electric signal to a pump laser CW1; the second low-loss band-pass filter is used for processing the electric signal converted from the QPSK signal and then sending the processed electric signal to the pump laser CW1; the pump laser CW1 is used for loading the output of the first low-loss band-pass filter and the output of the second low-loss band-pass filter to the optical laser; the first high-order nonlinear optical fiber HNLF1 is used for coupling the output of the optical laser and the output of the pump laser CW2; the second high-order nonlinear optical fiber HNLF2 is used for coupling the output of the first high-order nonlinear optical fiber and the output of the pump laser CW3; and the OFDM demodulator is used for demodulating and outputting the output of the second high-order nonlinear optical fiber.

An optical-resolution photoacoustic microscopy (OR-PAM) system for visualizing water content deep in biological tissue uses an all-fiber 1930-nm hybrid optical parametrically-oscillating emitter. The emitter includes a tunable laser source whose output is amplified by a first erbium-doped fiber amplifier (EDFA). The output of the first amplifier is modulated with a Mach-Zehnder amplitude modulator that receives an RF signal with a nanosecond pulse width and a multiple kilohertz repetition rate. A second EDFA further amplifies the signal and passes it to a fiber circulator that in turn delivers it to a 1950 / 1550 mm fiber wavelength-division-multiplexing coupler WDM. The coupler introduces the signal to a cavity that includes a spool of highly nonlinear fiber and a Thulium-doped fiber amplifier TDFA. From the TDFA the signal reaches a 50 / 50 fiber coupler that sends part to a second output TDFA and guides part back to the cavity through a port of the WDM.

A kind of multi-threshold phase encoding-based all-optical quantization system belongs to all-optical analog-digital conversion field.It includes high repetition frequency femtosecond pulse light source,1×M optical splitter,phase-shifted optical quantization module, soliton self-frequency shift module and multi-threshold encoding module;The phase-shifted optical quantization module is M-path electro-optic modulator;The soliton self-frequency shift module includes first M-path high nonlinear fiber,M-path single-mode fiber and second M-path high nonlinear fiber;The multi-threshold encoding module includes M wavelength division multiplexer,M×N optical delay line array,M×N photodetector array and encoding module.The present application uses multi-threshold encoding module of phase encoding,realizes simultaneous judgment of multiple threshold points on power transmission curve of M electro-optic modulators, solves code type repetition problem of all-optical quantization system,realizes more effective quantization states with less channel number,improves quantization precision.Meanwhile,quantization bit number of the present application is improved to log2(2MN).

This invention discloses a wide-tunable single-passband microwave photonic filter and its construction method. The filter includes a light source device for generating a supercontinuum light source, comprising a generator, an RF power amplifier, a DFB laser, a first erbium-doped fiber amplifier, a first variable optical attenuator, and a highly nonlinear fiber connected in sequence. An optical filter for selecting a certain width of supercontinuum light source is connected between the light source device and a MZI structure for spectral segmentation of the supercontinuum light source. The MZI structure is connected to a photodetector via a single-mode fiber and a second erbium-doped fiber amplifier. The photodetector is connected to the MZI structure via a vector network analyzer. This application features a simple structure, low cost, and the constructed complex coefficient filter eliminates the fundamental frequency response.

The application discloses a single-seed-source-based all-fiber flat ultraviolet-mid-infrared supercontinuum laser, which comprises a seed laser, two-stage ytterbium-erbium-doped fiber amplifiers, a high-nonlinear fiber NL-1550, a large-mode-field ytterbium-erbium-doped fiber amplifier, a large-mode-field ytterbium-doped fiber amplifier, a photonic crystal fiber and a passive fluorine-doped fiber which are connected in sequence; wherein the seed laser outputs seed pulse laser of 1.55 mu m, and finally outputs supercontinuum laser with a spectral range of 370-4500 nm, covering ultraviolet-mid-infrared bands. The application adopts an all-fiber structure, has high stability and portability, reduces the loss in the process of light transmission and the system complexity, realizes double-wavelength pumping through a seed source, and realizes super-flat spectral output covering ultraviolet to mid-infrared through a multi-stage amplification structure and a multi-stage nonlinear medium structure.

A kind of mid-infrared laser generation system based on dispersion control soliton group pulse, can obtain high-power, high-efficiency, high-occupancy mid-infrared laser output, has the advantages of all-fiber, compact structure, high power occupancy in mid-infrared rear spectrum. The pulsed fiber laser generates nanosecond pulsed laser at 1.5 microns wavelength; the fiber pulse stretcher is a single-mode quartz optical fiber, which splits the nanosecond pulse into multiple ultrafast soliton pulses through nonlinear effect, and performs spectral energy conversion from 1.5 microns to 2.4 microns; the fiber laser amplifier further improves the output power of the stretched pulse laser and expands the spectrum to 2.7 microns wavelength, while improving the pulse energy after 2.3 microns wavelength; the fiber mode field adapter efficiently couples the pulse generated in the fiber laser amplifier into the nonlinear fiber; the nonlinear fiber expands the laser to the mid-infrared 3-5 microns wavelength, and obtains high-power, high-efficiency, high-occupancy mid-infrared laser output.

The invention discloses a high-power and high-coherence 1645nm femtosecond fiber laser based on nonlinear gain modulation, the output wavelength is adjustable, the whole U wave band (1620-1680nm) can be covered, and a system comprises an erbium-doped mode-locked laser, an optical circulator, a fiber bragg grating, an erbium-doped fiber amplifier, a single-frequency laser, a coupler, a nonlinear fiber, an optical splitter and a pulse compressor. An ultrafast pulse generated by the mode-locked laser is filtered and amplified by the fiber bragg grating, the ultrafast pulse and 1645nm single-frequency laser are injected into the nonlinear fiber, nonlinear gain modulation is performed on the single-frequency laser, so that the time domain of the single-frequency laser is shaped into the ultrafast pulse, and femtosecond pulse output can be realized after compression. The tuning single-frequency laser can realize continuous tuning of an output spectrum, and covers the whole U wave band. The U-band femtosecond pulse generating device generates U-band femtosecond pulses with the power of the magnitude of several watts, and fills the gap of erbium and thulium ion emission spectra. The high-coherence and high-power U-band femtosecond light source is suitable for a plurality of fields such as atmospheric remote sensing, imaging, communication, radar and the like.

According to the optical frequency comb generation method with the designable spectrum envelope based on machine learning, interpolation is carried out on collected optical frequency comb spectrum data, so that more accurate peak value envelope and valley value envelope data of the optical frequency comb spectrum are extracted. The peak envelope serves as an input data set of a machine learning system, the valley envelope serves as an output data set of the machine learning system, the machine learning system is trained, and the corresponding valley envelope can be predicted through the peak envelope. According to the method, machine learning is applied to reconstruction from a frequency spectrum envelope to a complete optical frequency comb and determination of various modulation parameters of an initial optical frequency comb. And finally, performing specific modulation on the initial optical frequency comb and inputting the modulated initial optical frequency comb into a nonlinear optical fiber, and by utilizing the spectrum broadening characteristic of the nonlinear optical fiber, the obtained spectrum envelope type does not depend on a fixed mathematical function model, but supports multiple forms of envelope definition modes, including definition based on a control point interpolation mode.

This invention discloses a broadband fiber laser nonlinear amplification device and its operating method. The device includes a front-end light source, a first isolator, a nonlinear fiber laser amplification stage, a second isolator, a broadband fiber laser amplification stage, and a compressor connected in sequence. The isolator ensures unidirectional transmission between amplifiers. The picosecond or femtosecond light source at the front end passes through the nonlinear fiber laser amplification, and under the action of strong nonlinearity, the spectrum is broadened to a bandwidth of tens or even hundreds of nanometers. This process gives the pulse linear chirp in the time domain and breaks through the active gain bandwidth limit in the frequency domain, with a chirped pulse width of only tens of femtoseconds. The broadband fiber laser amplification stage utilizes large mode area fiber, which can achieve pulse energy amplification while maintaining the broadband spectrum and linear chirp of the laser. After passing through the compressor composed of grating pairs or prism pairs, the pulse width can still be compressed to tens of femtoseconds.

A supercontinuum source including a pump light source arranged to emit pump light and a nonlinear fiber having a core arranged to receive the pump light. The supercontinuum includes infrared wavelengths generated in the nonlinear fiber from the pump light. The nonlinear fiber has a dispersion profile including a zero dispersion wavelength, a positive peak value at a peak wavelength longer than the zero dispersion wavelength, a minimum value of dispersion at a minimum wavelength longer than the peak wavelength. The pump light is arranged to include substantial energy at one or more preferred pump wavelengths which are 10 nm longer than the zero dispersion wavelength or more. Also, a supercontinuum pump source including a nonlinear fiber having a core including a fluoride glass and having a core diameter smaller than 7 μm, where the fiber has a numerical aperture of more than 0.26.