64 results about "Mode-locking" patented technology

The invention relates to a sweep frequency optical frequency comb generation system and a generation method. Fourier mode locking is realized through a Fourier mode locking photoelectric oscillator system. The sweep frequency optical frequency comb generation system is a closed Fourier mode-locked laser loop which is composed of a first optical amplifier, an optical fiber isolator, a broadband filter, a polarization controller, a thin film lithium niobate optical chip, a signal generator, a dispersion compensation optical fiber and a first optical coupler; and a photoelectric oscillator loop is formed by a second optical coupler, a single-mode delay optical fiber, a second optical amplifier, a photoelectric detector, a narrow-band filter, a low-noise amplifier and an electric power divider. Time domain active mode locking and Fourier mode locking are carried out on the laser resonant cavity at the same time, synchronous modulation of multiple optical frequency comb modes is achieved, sweep frequency optical frequency comb signals with high repetition frequency, high modulation speed, high coherence length and high output power are generated, and tunable optical frequency comb and high-quality high-frequency microwave signal output can be provided at the same time.

The utility model provides an NPE mode-locking polarization-maintaining large-mode-field fiber laser with enhanced self-starting capability, and relates to the technical field of fiber lasers, the fiber laser comprises a pumping source and a laser oscillation cavity, the pumping source is connected with a gain fiber through a fiber beam combiner, and the laser oscillation cavity is connected with the gain fiber through a fiber beam combiner. The gain fiber is connected with a spatial light path of the laser oscillation cavity part through the photonic crystal fiber, a polarization beam splitter is arranged in the laser oscillation cavity, and a phase shifter is arranged between the polarization beam splitter and a spatial light path of the pumping source part and used for realizing nonlinear polarization rotation (NPE) mode locking; the polarization beam splitter is arranged at the position where two orthogonal polarization states transmitted in the optical fiber interfere, dual-port output of the laser is provided, vertical polarized light is output from a reflection port, horizontal polarized light is output from a transmission port, and the mode locking self-starting capacity and stability of the laser are improved.

The invention provides a femtosecond pulse width precision adjustment compensation device and method, and relates to the technical field of laser processing, the device comprises a mode locking seed source, a stretcher, an amplifier, a first compressor and a second compressor; the second compressor comprises a movable reflecting mirror, a climbing mirror, a grating and a grating base material; the movable reflecting mirror is configured to adjust the diffraction times of the femtosecond laser on the grating by changing the distance between the movable reflecting mirror and the grating base material; the grating base material is made of a nonlinear material and is used for generating a self-phase modulation effect under the action of femtosecond laser to realize spectrum broadening and pulse compression; precise adjustment compensation of the femtosecond pulse width is achieved by adjusting the diffraction times. The invention provides a technical scheme which not only can bear high-power and high-energy laser, but also can realize on-line precise adjustment and compensation of pulse width.

The invention discloses a near-infrared wide-spectrum pulse light source generator, belongs to the technical field of laser light source manufacturing, and aims to solve the problems of complex system structure and high cost due to the fact that a supercontinuum laser generates supercontinuum through multi-stage power amplification in the prior art. The device is composed of a first semiconductor pump laser, a first wavelength division multiplexer, a first gain optical fiber, a first filter, a first dispersion compensation optical fiber, a first high-nonlinearity optical fiber, a first isolator, an optical fiber coupler, a second semiconductor pump laser, a second wavelength division multiplexer, a second gain optical fiber, a second filter, a second dispersion compensation optical fiber, a second high-nonlinearity optical fiber and a second isolator. According to the invention, the characteristic of high mode-locked pulse energy of the Mmyshev oscillator is utilized, multi-stage power amplification is not needed, and the super-continuum spectrum can be directly generated, so that the system structure is simplified, and the cost is reduced; the laser light source can be applied to multiple fields of laser sensing, photoelectric countermeasure, remote sensing detection, optical imaging and the like.

The present invention discloses a multimode four-wave mixing (FWM) automatic mode-locking device and method. The device comprises: a host computer, an electric polarization controller, a spatiotemporal mode-locked laser, an oscilloscope, and a spectrometer. The host computer is connected to the spatiotemporal mode-locked laser; the electric polarization controller is located within the spatiotemporal mode-locked laser; the inputs of the oscilloscope and spectrometer are connected to the spatiotemporal mode-locked laser, and the outputs of the oscilloscope and spectrometer are connected to the host computer. The host computer is configured to output a voltage to control the electric polarization controller, acquire data from the oscilloscope and spectrometer, and execute a FWM automatic mode-locking algorithm. The electric polarization controller receives a voltage signal from the host computer, regulates the polarization state and fiber length of the spatiotemporal mode-locked laser, and changes the energy coupling between different transverse modes within the spatiotemporal mode-locked laser. The present invention achieves automatic mode-locking of FWM by automatically detecting the FWM phenomenon.

The invention provides a 2-micron all-fiber noise-like space-time mode-locked laser generation and control device and method. The 2-micron all-fiber noise-like space-time mode-locked laser generation and control device comprises a laser generation subsystem and a device regulation and control and image feedback subsystem. Wherein the laser generation subsystem is used for generating a laser pulse with a high-order transverse mode and realizing noise-like space-time mode locking; and the device regulation and image feedback subsystem is used for controlling the output power and temperature of a pumping source, regulating an electronic polarization controller, reading light spot image data through a CCD (Charge Coupled Device) camera to form a closed-loop feedback loop, and realizing state self-recognition and fault self-repair of space-time mode locking through a computer intelligent algorithm. The method has the advantages of being high in practicability, simple in equipment, easy to operate and the like, and stable output of the 2-micron noise-like space-time mode-locked laser is achieved only through a CCD image feedback means without other detection equipment such as an oscilloscope and a spectrograph.

The invention belongs to the technical field of optical fiber lasers, and discloses a multi-soliton-state adjustable optical fiber laser based on a time delay polarization multiplexing structure. The fiber laser comprises a laser pumping source, a wavelength division multiplexer, an erbium-doped gain fiber, a polarization independent isolator, a mode locking device based on a carbon nanotube saturable absorber, a polarization beam splitter, a polarization beam combiner and an output coupler which are sequentially connected through a single-mode fiber. A time delay polarization multiplexing structure of the optical fiber laser adopts a combination of a polarization beam splitter, a single-mode optical fiber and a polarization beam combiner, and the lengths of the single-mode optical fibers on two branches are obviously different. Therefore, traditional solitons conforming to independent mode locking of the long and short cavities can be output, and long-cavity or short-cavity-dominated master-slave soliton equally-spaced soliton beams and long-cavity and short-cavity periodic alternately-spaced pulse output can be generated. According to the invention, by introducing a time delay polarization multiplexing structure, the limitation of a traditional annular cavity is broken through, and a new solution is provided for the generation and dynamic regulation of multiple soliton states.

The invention discloses a 2-micron short-period laser amplifier based on a thulium-doped positive dispersion fluorotellurite optical fiber, which can solve the problem that a negative dispersion thulium-doped optical fiber is not suitable for performing gain management nonlinear amplification on a 2-micron pulse, and can obtain a pulse width lt. 50 fs, and single pulse energy gt; the femtosecond laser output device has the advantages of being full-fibrillated and compact in structure. The 2-micron femtosecond seed source is femtosecond pulse laser of a 2-micron wave band generated based on nonlinear amplification loop mirror mode locking; the chirped pulse amplifier is used for obtaining sub-picosecond 1.9 mu m femtosecond laser output with the average power greater than or equal to 1W; the optical fiber GMN amplifier is used for obtaining a few-period femtosecond pulse; the high-power optical fiber pulse compressor is a hollow-core optical fiber and is used for carrying out accurate dispersion compensation and high-quality pulse compression.

The present application relates to a dual-comb laser, and in particular to a direction-polarization multiplexing single-cavity dual-comb laser, which solves the technical problems of the prior art that pulse components in different polarization directions are difficult to separate, leading to high difficulty in dual-polarization mode locking, harsh implementation conditions, or difficulty in adjusting the pulse repetition frequency difference, and the numerical value is small, or the mutual coherence of the output pulse sequence is low, and the signal-to-noise ratio is low. The present application adopts a full polarization maintaining optical fiber resonant cavity with a polarization beam splitter as a central node and a double-linked ring cavity structure composed of ring structure A and ring structure B. The laser transmitted in the counterclockwise direction in the ring structure A is cut off, and the laser transmitted in the clockwise direction is separated by the polarization beam splitter and transmitted in the opposite direction in the ring structure B, partially output, and partially returned to the ring structure A, thereby realizing cyclic oscillation.

The invention relates to the technical field of lasers, and discloses a self-starting 9-shaped cavity optical fiber laser with an adjustable feedback loop and a using method, the self-starting 9-shaped cavity optical fiber laser comprises a non-linear amplification annular mirror and a linear arm, and a third coupler is arranged between the non-linear amplification annular mirror and the linear arm; the nonlinear amplification loop mirror comprises a gain optical fiber, a polarization-maintaining wavelength division multiplexer and a phase shifter, the gain optical fiber, the polarization-maintaining wavelength division multiplexer and the phase shifter are sequentially connected in a closed mode, and the polarization-maintaining wavelength division multiplexer is connected with the pumping source; the feedback unit is arranged on the nonlinear amplification loop mirror, the two ends of the feedback unit are communicated with the gain optical fiber and the polarization-maintaining wavelength division multiplexer respectively, and light output by the rear end of the gain optical fiber is fed back to the gain optical fiber through the feedback unit to form a feedback loop. By constructing a closed-loop feedback loop, the noise energy in the cavity is enhanced, the mode locking threshold and the starting time are reduced, the gain fiber amplification gain is dynamically adjusted, the nonlinear phase shift accumulation is stably controlled, an external complex system is avoided, and the all-fiber low-cost efficient design is realized.

The application relates to a 9-shaped cavity laser with independently and continuously tunable wavelength and pulse width, which comprises a 9-shaped cavity oscillator and a laser parameter tuning and state monitoring feedback system. The 9-shaped cavity oscillator can realize self-starting fundamental mode locking through the introduction of a non-reciprocal device and the optimization of the positions of the devices in the 9-shaped cavity oscillator and the lengths of the optical fibers. The laser parameter tuning and state monitoring feedback system can continuously tune the wavelength and pulse width of the 9-shaped cavity oscillator, and can monitor the output state of the oscillator in real time to determine whether the oscillator is in a stable mode-locked state and control the angle of a half-wave plate and the current value of a laser diode by using a random collision recovery algorithm so that the 9-shaped cavity oscillator can always keep in a stable mode-locked state. The application can realize the independent and continuous tuning of the wavelength and pulse width of the 9-shaped cavity laser in a stable mode-locked state, and has a wide application prospect in the field of tunable lasers.

The application discloses a kind of high-power laser seed sources for multimodal medical imaging based on germanium saturable absorber, it is characterized in that, including first pump light source, second pump light source and laser resonator, the laser resonator is by first wave division multiplexer, second wave division multiplexer, erbium-doped optical fiber, polarization controller, polarization independent isolator, germanium saturable absorber, single-mode optical fiber, optical coupler sequentially connected, the first pump light source is connected with first wave division multiplexer, and second pump light source is connected with second wave division multiplexer.The germanium saturable absorber prepared in the application has good self-starting effect on pulse, the preparation method is simple, and the preparation cost is not high.And the stability of the obtained saturable absorber is good, and it can be used for passive mode locking for a long time.

The invention provides a covalent organic framework material with saturated absorption property as well as a preparation method and application of the covalent organic framework material. The covalent organic framework material (COF) is synthesized at room temperature by utilizing an interface synthesis method, so that the influence of high-temperature and high-pressure harsh conditions and a high-temperature hot solvent in a traditional method on the environment is avoided, and the concept of green chemistry is embodied. According to the invention, by constructing a COF structure, the reversion of the properties of copper tetraamino phthalocyanine (CuTaPc) RSA-SA is realized. According to the invention, the COF material is introduced into the resonant cavity as a saturable absorber for the first time to realize passive mode locking of 1 [mu] m and 1.5 [mu] m, and near-infrared ultrashort pulse laser is generated, which proves that the obtained material can be used as a new saturable absorber material suitable for ultrafast and ultra-narrow fiber lasers.

The application provides a frequency stabilized laser device and a quantum communication system, and relates to the technical field of lasers.The frequency stabilized laser device comprises: a first distributed feedback laser for generating a first laser; a second distributed feedback laser for generating a second laser; an inner closed loop for cavity mode locking of the first distributed feedback laser and the second distributed feedback laser respectively, so as to suppress noise and cavity length disturbance and complete short-term stable regulation; and an outer closed loop for beat frequency processing of the first laser and the second laser according to a reference frequency, so that the frequencies of the first laser and the second laser remain stable, the long-term thermal drift of the first distributed feedback laser and the second distributed feedback laser is suppressed, and short-term and long-term stability is unified.The application can solve the technical problems that the existing laser cannot simultaneously realize short-term low noise and long-term low drift, the stable cavity effect is poor, and frequency difference monitoring is difficult, and realizes the unification of short-term stability and long-term stability of the laser signal.

The invention discloses a high-precision correlation ranging system based on chaotic laser, and the system is characterized in that a transmitting end employs a VCSEL coherent array module, converts chaotic continuous light into pulse light and excites correlation mode locking through current pulse and orthogonal polarized light injection (OPIOI) modulation, and combines a photonic crystal coupler (hexagonal close arrangement, orthogonal polarized light injection, orthogonal polarized light injection, orthogonal polarized light injection, orthogonal polarized light injection, orthogonal polarized light injection, orthogonal polarized light injection, orthogonal polarized light injection, orthogonal polarized light injection and orthogonal polarized light injection); the crystal lattice is 220nm / hole is 66nm), so that high-power and broadband TDS-free chaotic pulse synthesis is realized; a receiving end converts signals through a Geiger mode APD, an FPGA stores echoes in a BRAM in a segmented mode, cyclic shift XNOR operation and multi-segment cross-correlation accumulation are executed, time delay peak positioning is optimized in combination with a convolutional neural network, and finally a ranging value (the precision is superior to 1 micron) is output. The system has the advantages of anti-interference characteristic of chaotic laser and high resolution of pulse distance measurement, and supports USB serial port communication and real-time display of an upper computer. According to the invention, the problem of distance ambiguity of distance measurement by a phase method is solved, and meanwhile, the precision defect of a pulse method in dynamic target measurement is overcome.

The application provides a laser and a mode locking method based on a discrete echo wall microcavity, and relates to the technical field of lasers.The laser provided by the application comprises a pumping source, a resonant cavity packaging module and a feedback control module;the resonant cavity packaging module comprises a polarization maintaining fiber group, a phase modulator and an echo wall mode resonant cavity which are packaged in a shell;the polarization maintaining fiber group is coupled to the echo wall mode resonant cavity at a fixed distance;and the feedback control module is used for mode locking the resonant cavity packaging module.The laser and the mode locking method provided by the application design corresponding structures based on a discrete echo wall microcavity, solve the problem of precise coupling between an external cavity module and a laser chip, make the laser easy to assemble and deploy by realizing modular design, provide an adaptive compensation algorithm to enhance the locking effect, and provide a mode selection function for laser users to better support research in the fields of communication and calculation.

The present invention discloses a femtosecond disk laser combining active and passive mode locking, belonging to the field of disk lasers. The femtosecond disk laser comprises: a pump source, a pump cavity, a disk laser crystal, and a resonant cavity. The pump source emits pump laser light, which is reflected multiple times in the pump cavity and passes through the disk laser crystal multiple times to generate oscillating laser light. The resonant cavity comprises a first branch and a second branch. The first branch comprises a dispersion mirror group, a hard aperture, and an output mirror arranged in sequence along the optical path. The second branch comprises a first concave mirror, a second concave mirror, a first high-reflection mirror, a third concave mirror, an acousto-optic modulator, and a second high-reflection mirror arranged in sequence along the optical path. The acousto-optic modulator is located at the focus of the third concave mirror and modulates periodic loss during active mode locking and initiates passive mode locking. The oscillating laser light generates a femtosecond laser pulse sequence after passing through the acousto-optic modulator. The pulse sequence is then reflected back to the disk laser crystal along the original path, enters the first branch, and is output through the output mirror.

The invention discloses a repetition frequency tunable high-order collision mode-locked laser and an optical frequency comb, and the laser comprises a laser resonant cavity, the two ends of the laser resonant cavity are respectively provided with a high reflection coating end face and a low reflection coating end face, a saturable absorber SA region and a gain Gain region, the total length ratio of SA to Gain is 1: A, the resonant cavity is divided into (1 + A) large sections, each large section is divided into B small sections, and (1 + A) * B unit sections are arranged, the adjacent unit sections are electrically isolated and can be combined into an SA or Gain region through electrical connection; sA is composed of continuous B unit sections, Gain is composed of the remaining unit sections, and collision mode locking of different orders and repetition frequency tuning are achieved by changing the position of the SA. By changing the connection mode of the resonant cavity and combining with the conical ridge width structure, the high-power pulse light source with tunable repetition frequency is realized under the fixed resonant cavity, the system complexity and cost are reduced, the pulse stability and peak power are improved, and a scheme is provided for low-cost and miniaturized application.

The polarization multiplexing double-frequency comb laser with online polarization and mode locking belongs to the field of double-frequency comb lasers. The problems of large preparation difficulty of double-frequency comb optical system, instability of double-frequency comb output light source and uncontrollable power loss are solved. The passive mode locking is realized through the mode locker, and the circulating oscillation of the set direction of the resonant cavity is realized through the direction control component (polarization insensitive isolator or ring). Since the mode locker and the online polarizer are prepared by the side polished fiber, the preparation difficulty is small, the power loss is controllable, and the online polarizer is introduced to replace the traditional unstable polarization control. The online polarizer introduced makes the double-frequency comb more stable output. The present application is mainly used for generating stable double-frequency comb light.

The invention provides an intelligent control method and device for a high-power optical fiber femtosecond laser, and belongs to the technical field of optical fiber femtosecond lasers. Comprising mode locking control and temperature control, specifically, the intelligent mode locking system is controlled to perform mode locking operation according to a feedback signal of the repetition frequency detection system, the intelligent temperature control system is controlled to perform graded temperature adjustment according to a feedback signal of the temperature sampling unit, and the intelligent temperature control system is controlled to adjust temperature setting to assist in mode relocking when mode locking fails. The high-power fiber femtosecond laser control system can adapt to complex external environment changes, and fast and effective control over the high-power fiber femtosecond laser is achieved.

The present application provides a mode-locked pulse light generating filter that simply realizes self-starting mode locking, and a laser device that generates a picosecond, femtosecond pulse laser by being provided with the filter, the laser device being provided with an amplification section that amplifies light within a resonator and outputs the light, and a mode-locked pulse light generating filter that has a first filter section that selectively outputs a first wavelength component that is a wavelength component of an oscillation band within the resonator, and a second filter section that selectively outputs a second wavelength component that is a wavelength component different from the oscillation band.

The utility model belongs to the technical field of lasers, and discloses a 9-shaped hybrid mode-locked fiber laser, which comprises a pumping source, a 2 * 2 polarization-maintaining fiber coupler, a nonlinear amplification loop mirror loop connected with a first side of the polarization-maintaining fiber coupler, and a chirp fiber Bragg grating connected with a second side of the polarization-maintaining fiber coupler, the polarization maintaining optical fiber coupler is located at the connecting position of the nonlinear amplification annular mirror loop and a linear arm of the laser resonant cavity and used for coupling laser of the nonlinear amplification annular mirror loop to the linear arm, and after being reflected by the chirp fiber bragg grating, the laser is output to the nonlinear amplification annular mirror loop through the chirp fiber bragg grating. And then the laser on the linear arm is split into two beams of light which are transmitted clockwise and anticlockwise in a loop of the nonlinear amplification annular mirror. According to the utility model, two passive mode locking technologies are combined, rapid and stable mode locking can be realized, the operation state is slightly influenced by the environment, the signal-to-noise ratio of output laser pulses can be improved, and ultra-short pulses with narrower pulse width can be realized.

The invention belongs to the field of solid-state lasers, and particularly discloses a Kerr lens mode-locked self-starting-based solid-state laser which comprises a laser generating unit used for generating laser and a mode-locked regulation and control unit arranged on a laser emergent light path. And the mode-locked regulation and control unit comprises a half-wave plate, a polaroid and a target reflector which are sequentially arranged along a preset light path, and is used for regulating and controlling the light intensity of the laser reflected back to the laser generation unit in a polarization state regulation mode and triggering the mode-locked state of the Kerr lens in a light disturbance mode. According to the invention, the Kerr lens mode locking state can be effectively triggered, a traditional mechanical disturbance mode is abandoned, all-optical active triggering is realized, and the operation convenience and long-term operation stability of the laser are greatly improved; in addition, a user can adjust the laser system to an optimal mode-locking trigger state, and the success rate and repeatability of mode-locking self-starting of the Kerr lens are remarkably improved.

The present invention discloses a method and device for automatic mode-locking control and detection of an optical frequency comb. First, the optimal mode-locking state of the optical frequency comb is manually calibrated, and the power value range of the optical frequency comb output spectrum is recorded as standard data; a microcontroller controls and gradually increases the pump current of the pump source, and at the same time, the output light of the optical frequency comb oscillator is divided into three paths, the first path is used for mode-locking detection, the second path is input to an optical power meter, and the third path is used as measurement light for subsequent measurement; the first path of light is converted into an electrical signal, the electrical signal is amplified, mixed with a reference frequency to obtain an error signal, the error signal is filtered and converted into a voltage signal, and the microcontroller is used to detect the error signal. The microcontroller samples the voltage signal to determine whether mode locking is achieved. If mode locking has not been achieved, the pump current continues to increase. Mode locking is achieved when the microcontroller calculates the cumulative sum of the absolute deviations of two adjacent sampling results among multiple sampling results and finds that the sum is less than a set threshold. At this point, the microcontroller triggers serial communication with the optical power meter, reads the real-time power of the optical power meter, and determines whether the current power is within the power value range based on standard data. If so, optimal mode-locked pulse laser output is achieved. If not, the pump current needs to be reduced until the power value measured by the optical power meter meets the calibrated optimal mode-locked power value range. This invention can achieve automatic mode locking of the optical frequency comb and effective detection of the post-mode locking state, ensuring that the optical frequency comb oscillator has good spectral characteristics and signal light quality during actual output.

The invention relates to the technical field of semiconductor laser devices, in particular to a high-power-density distributed feedback type laser chip and a preparation process thereof. According to the technical scheme, the chip comprises a chip body, the chip body comprises a back electrode, a substrate, a lower waveguide layer, a lower limiting layer, an active layer, an upper limiting layer, an upper waveguide layer, a highly-doped layer and a front electrode which are sequentially stacked from bottom to top, and graphene layers are arranged on the sides, close to the active layer, of the lower limiting layer and the upper limiting layer. According to the invention, the graphene heat conduction layer and the conical bulge and micropore array are introduced between the active layer and the limiting layer, so that heat is directly and quickly dredged, thermal resistance and interface strain are reduced, heat accumulation is relieved from the source, and the reliability of the chip is improved; the artificial micro-nano grating formed by the conical structure and the DFB built-in grating cooperatively enhance longitudinal mode feedback, and improve the side mode rejection ratio and the light field limiting factor. Meanwhile, mode locking and 1 microsecond-level wavelength tuning are achieved through array type current injection, and the light spot and coupling efficiency is improved in cooperation with a unit-level micro lens.

The invention relates to a laser, in particular to a wavelength-tunable mode-locked laser, which comprises a self-made phase shifter, the self-made phase shifter is connected to a wavelength division multiplexer through a collimator and a polarization-maintaining erbium-doped fiber, the wavelength division multiplexer is connected to a pumping source, the wavelength division multiplexer is connected to a beam splitting end of a third polarization beam splitter through a polarization-maintaining single-mode fiber and the collimator, and the third polarization beam splitter is connected to a beam splitting end of a fourth polarization beam splitter through a polarization-maintaining erbium-doped fiber. The self-made phase shifter is connected with the optical fiber coupler through the collimator and the polarization-maintaining single-mode optical fiber, the optical fiber coupler is connected with the other beam splitting end of the third polarization beam splitter through the polarization-maintaining single-mode optical fiber and the collimator, and the beam combining end of the third polarization beam splitter is connected with the adjustable filter through the single-mode optical fiber. The adjustable filter is connected with the 90-degree Faraday rotating reflector through the single-mode fiber; according to the technical scheme provided by the invention, the defect that high-precision wavelength-tunable stable mode locking is difficult to carry out on the laser in the 1550 nm waveband in the prior art can be effectively overcome.

The invention discloses a high repetition frequency wide spectrum all-fiber femtosecond oscillator with a full polarization-maintaining structure, which comprises an LD semiconductor pump laser, a polarization-maintaining wavelength division multiplexer of a DEWDM composite fiber, a PS phase delay polarization-maintaining rotating mirror, an OC polarization-maintaining fiber coupler and an AM polarization-maintaining holophote, the polarization-maintaining wavelength division multiplexer of the DEWDM composite optical fiber comprises a first polarization-maintaining single-mode optical fiber, a dispersion compensation optical fiber, a wavelength division multiplexer and a high-gain erbium-doped optical fiber. The phase delay rotating mirror is added, the mode locking self-starting characteristic is improved, the dispersion compensation optical fiber is added, dispersion management in the cavity is achieved, and narrower pulse width and wider spectrum can be obtained.

The embodiment of the invention provides a femtosecond laser beauty instrument system based on a full polarization-maintaining linear cavity seed source and a use method, and belongs to the technical field of laser equipment. The system comprises a full polarization-maintaining linear cavity femtosecond laser seed source module, a femtosecond laser amplification module, a laser transmission module, a treatment head module, an energy monitoring and feedback module and an intelligent control module. The seed source module is used for executing self-starting mode locking output by adopting a non-reciprocal mode locking mechanism; the amplification module is used for performing optical fiber amplification and pulse width compression on the femtosecond laser; the laser transmission module is used for transmitting the amplified femtosecond laser through a polarization maintaining optical fiber; the treatment head module is used for focusing the femtosecond laser transmitted to the treatment end to skin tissue; the energy monitoring and feedback module is used for detecting the fluctuation range of laser energy on line; the intelligent control module is used for integrating parameter setting and fault detection. According to the embodiment of the invention, stable output of femtosecond pulse energy can be ensured, system miniaturization and operation intellectualization are realized, and the overall cost is reduced.

The invention belongs to the technical field of lasers, and particularly provides a high repetition frequency 9-shaped cavity fiber laser which comprises a wavelength division multiplexing coupler, a laser output assembly and a nonreciprocal phase shift assembly used for generating nonlinear phase shift. The non-reciprocal phase shift assembly comprises a phase shifter and a tapering optical fiber; the phase shifter is located on an emergent light path of the wavelength division multiplexing coupler; the input end of the tapering optical fiber is located on an emergent light path of the phase shifter, and the output end of the tapering optical fiber is connected with the wavelength division multiplexing coupler; the laser output assembly is connected with the wavelength division multiplexing coupler; and the laser output assembly is used for reflecting one part of the laser input by the wavelength division multiplexing coupler back to the wavelength division multiplexing coupler and outputting the other part of the laser. According to the high repetition frequency 9-shaped cavity fiber laser, the tapering fiber area is integrated in the non-reciprocal phase shift section, so that non-linear phase shift enough for mode locking can be generated without a very long passive fiber, the cavity length is shortened, the repetition frequency is improved, and the fiber laser can output laser with high repetition frequency.

The present invention discloses a fast, electrically controllable 100-picosecond pulse laser. The laser includes a resonant cavity, a pump light source, and a radio frequency signal source. The laser's ring resonant cavity includes an integrated device, a gain fiber, a single-mode fiber, a phase modulator, and a polarization controller. The integrated device has the functions of a wavelength division multiplexer, a polarization-independent isolator, and a coupler. The radio frequency signal source is connected to the phase modulator via a radio frequency cable. Electrical modulation of the light field is achieved by inputting an electrical signal into the phase modulator via a signal source. The phase modulator contains a polarizer, and the light intensity at its output end is sensitive to the polarization state of the light field at the input end, so that the phase modulator has the effect of intensity modulation. Combining the polarization controller and the integrated device can achieve nonlinear polarization rotation mode locking. The output light polarization state of the phase modulator is related to the voltage of the electrical signal, which can achieve fast electrical modulation of the light pulse. The present invention can greatly improve the modulation rate of the light pulse and has the advantages of fast and flexible modulation.