86 results about "Mode-locking" patented technology

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

The invention relates to a self-optimization control method and system for a mode-locked state of a solid laser. Firstly, an initial data set containing at least one of pulse width, frequency, temperature and vibration data is obtained, then the initial data set is preprocessed, and a mode locking stability feature set is extracted from the initial data set. And then, inputting data in the mode locking stability feature set into a support vector machine model so as to obtain a mode locking strength predicted value. And then, calculating a deviation value between the mode locking strength predicted value and the real-time data, generating an optimization decision value by using Kalman filtering, and if the deviation between the optimization decision value and the real-time data exceeds a preset threshold value, adjusting operation parameters. And finally, inputting the adjusted operation parameters into a mapping relation model optimized by using a gradient descent algorithm, and further generating a dynamic power configuration scheme. According to the method, the stability and automatic regulation and control of the mode locking state are realized, the efficient utilization of resources is realized, and the performance and adaptability of the solid laser are greatly improved.

To provide mechanisms for providing a source for circular-ranging OCT at moderate speeds.SOLUTION: A source for providing electromagnetic radiation within a particular spectral range includes: a ring-shaped optical resonator for circulating a plurality of wavelength bands including a first optical phase modulator, a first chromatic dispersion device, a second optical phase modulator, a multi-line spectral domain filter, a second chromatic dispersion device, and an optical amplifier; and a controller coupled to the first optical phase modulator and the second optical phase modulator, the controller being configured to drive the first optical phase modulator with a first waveform and the second optical phase modulator with a second waveform.SELECTED DRAWING: Figure 2

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 discloses a mode locking system and a mode locking method suitable for microcavity ultrasonic detection. The system comprises a control module, a laser output module and a detection module, the laser output module comprises a single-frequency laser, a temperature adjusting unit, a temperature detection unit and a heat transfer unit, and the detection module is used for detecting a transmission spectral line of the microcavity ultrasonic probe and transmitting the transmission spectral line to the control module; the control module is used for controlling the temperature in the cavity of the single-frequency laser through the linear interpolation data, realizing linear regulation and scanning of the wavelength entering the cavity, and screening and locking the microcavity mode of the microcavity ultrasonic probe; the device is also used for detecting a locking site of a microcavity mode by adopting a temperature detection and light intensity voltage feedback design, and automatically adjusting the temperature in a mode drift process to adjust the wavelength so as to correct the mode drift of the microcavity. The functions of mode scanning, active mode selection and mode locking of the microcavity ultrasonic probe can be autonomously completed, and a stable, reliable, low-cost and high-sensitivity new scheme is provided for ultrasonic detection.

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 invention relates to the technical field of optical fiber lasers, in particular to a GHz high repetition frequency mode-locked pulse laser. In the invention, a 980nm narrow linewidth laser is used as a pumping source to provide resonant cavity excitation, a section of erbium-doped fiber is used as an intra-cavity gain medium, a Mach-Zehnder phase modulator is used as an intra-cavity mode locking device, and the loss in the resonant cavity is periodically modulated through the Mach-Zehnder phase modulator, so that the resonant cavity is formed. In addition, the cavity length of the laser is about 8.45 m, and the corresponding intra-cavity fundamental frequency is 24.4 MHz, so that the laser can realize harmonic mode locking at the integral multiple of 24.4 MHz, the laser can realize harmonic mode locking with the stable duration longer than 6 hours at the 41st-order harmonic wave and the 42nd-order harmonic wave respectively, the laser is further matched with an external TEC temperature control platform, and the laser can be used for controlling the temperature of the TEC. And the stability and harmonic suppression ratio of the active mode-locked laser can be effectively improved.

The present invention discloses a method and device for automatically detecting mode locking of an optical frequency comb with a wide frequency band. The current of a pump source is controlled by an FPGA to enable the optical frequency comb oscillator to output optical frequency comb pulsed laser. The optical frequency comb pulsed laser is divided into two paths by a beam splitter for output. The first path serves as the measurement light for subsequent measurement. The second path is converted into an electrical signal by a photodetector I for subsequent judgment of the mode locking state. The FPGA controls and gradually increases the pump current of the pump source. Meanwhile, the electrical signal converted by the photodetector I is input into a radio frequency power detector, and a detected voltage signal is output according to the peak characteristics of the electrical signal. When it is judged through the detected voltage signal that the pulse peak value of the electrical signal output by the photodetector I is greater than 1V, the detected voltage signal is sampled multiple times. The absolute value of the difference between two adjacent sampling results is taken and accumulated. When the accumulated sum is less than the threshold set by the microcontroller, it is judged that the optical frequency comb has completed mode locking, and at this time, the increase of the pump current is stopped. The present invention can achieve automatic mode locking of the optical frequency comb and effective detection of the state after mode locking.

According to the invention, the optical signal wavelength test module, the optical signal frequency test module, the optical signal intensity test module and the optical signal rate test module are arranged to detect the wavelength, frequency, intensity and rate of an input optical signal; the method comprises the following steps: firstly, carrying out all-optical clock recovery processing on optical signals with different wavelengths and rates by setting a single recovery module and a multi-recovery module; classifying the optical signals with different wavelengths and rates; whether to carry out photoelectric signal conversion is to carry out mode locking by using a traditional electric module or directly carry out optical mode locking by using an active mode-locking laser module capable of carrying out mode locking on an optical signal with a higher transmission rate is determined by detecting the rate of the optical signal, so that the situation that the traditional electric module cannot process the optical signal with an overhigh rate is prevented; processing can be carried out according to different optical signal transmission rates; the mode locking modes of different electric signals after photoelectric transmission are determined by detecting the intensity and frequency of optical transmission signals.

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 provides a laser based on a discrete echo wall microcavity and a mode locking method, and relates to the technical field of laser. The laser provided by the invention comprises a pumping source, a resonant cavity packaging module and a feedback control module, the resonant cavity packaging module comprises a tapered optical fiber group, a phase modulator and an echo wall mode resonant cavity which are packaged in a shell; the tapering optical fiber group is coupled with the echo wall mode resonant cavity at a fixed distance; and the feedback control module is used for locking the mode of the resonant cavity packaging module. According to the laser and the mode locking method provided by the invention, a corresponding structure is designed based on the discrete echo wall micro-cavity, the precise coupling problem of the outer cavity module and the laser chip is solved, the laser is easy to assemble and deploy by realizing the modular design, and a self-adaptive compensation algorithm is provided to enhance the locking effect, so that the mode locking method has the advantages of high reliability and high reliability. And a mode selection function is provided for a laser user so as to better support research in the fields of communication, calculation and the like.

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 present application discloses a wide-band saturable absorber and a multi-soliton state laser. In the first aspect of the present application, the application of two-dimensional germanium sulfide in saturable absorber materials, saturable absorber devices, lasers and equipment is provided. According to the application of the embodiments of the present application, at least the following beneficial effects are achieved: the applicant discovered during the experiment that the GeS two-dimensional material has a narrow band gap of about 1.6 eV, and the size of the band gap can be tuned by external strain, so it is inferred that it has a wide-band saturable absorption, and the wide-band responsiveness of the saturable absorber device based on the GeS two-dimensional material is confirmed by experiments. Furthermore, the laser made of the saturable absorber device based on the GeS two-dimensional material has good tolerance to high pump power, and pulse splitting will occur under high pump power, resulting in multi-pulse mode locking and harmonic mode locking, and the generation of multi-soliton state phenomenon, so that this laser has certain research value and application value.

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 present invention discloses a self-starting nine-cavity laser and device based on motor perturbation, relating to the technical field of lasers; the laser includes a non-linear amplification loop, a linear arm, a polarization-maintaining fiber coupler, and a motor perturbation module. The polarization-maintaining fiber coupler is respectively connected to the linear arm and the non-linear amplification loop. By applying high-frequency mechanical vibration to the polarization-maintaining passive fiber in the non-linear amplification loop through the motor perturbation module, a high-intensity initial noise signal is promoted to form in the cavity, promoting mode competition in the cavity and accelerating the entry of the noise into the positive feedback region of the resonant cavity. Self-starting of mode locking is realized under low pump power conditions, reducing waste of pump power and lowering the cost of the device.

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 invention discloses a multimode four-wave mixing automatic mode locking device and method. The device comprises an upper computer, an electric polarization controller, a space-time mode locking laser, an oscilloscope and a spectrograph. Wherein the upper computer is connected with the space-time mode-locked laser; the electric polarization controller is located in the space-time mode-locked laser; the input ends of the oscilloscope and the spectrograph are connected with the space-time mode-locked laser, and the output ends of the oscilloscope and the spectrograph are connected with the upper computer; the upper computer is used for outputting voltage to control the electric polarization controller, acquiring data of the oscilloscope and the spectrograph and executing a four-wave mixing automatic mode locking algorithm; and the electric polarization controller is used for receiving a voltage signal from the upper computer, regulating and controlling the polarization state and the optical fiber length of the space-time mode-locked laser, and changing energy coupling of different transverse modes in the space-time mode-locked laser. According to the invention, the four-wave mixing phenomenon is automatically detected, so that automatic mode locking of four-wave mixing can be realized.

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 is suitable for the technical field of laser devices, and provides a femtosecond laser seed source and a laser device, and the femtosecond laser seed source comprises a total reflection mirror with dispersion, which is provided with a first chirp mirror; a wavelength division multiplexer; the coupler is connected to the total reflection mirror with dispersion; the doped optical fiber is connected to one side, far away from the total reflection mirror with dispersion, of the coupler and is connected to the wavelength division multiplexer; the polarization maintaining optical fiber is connected to the wavelength division multiplexer; the reflective phase shifter with dispersion is provided with a second chirp mirror, and the reflective phase shifter with dispersion is connected to the polarization maintaining optical fiber and one side, far away from the total reflection mirror with dispersion, of the coupler; and the pumping source is connected to the wavelength division multiplexer. The femtosecond laser seed source provided by the embodiment of the invention can realize low-threshold mode locking.

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.