1350results about "Optical resonator shape and construction" patented technology

The invention belongs to the technical field of topological photonic crystals, and discloses a topological laser resonant cavity, a design method thereof and a topological valley photonic crystal laser. According to the invention, three different photonic crystal areas are utilized to form a three-layer heterostructure, and the three different photonic crystal areas are divided into A, B and A'areas according to the same lattice period array arrangement; the area A and the area A'are the innermost layer and the outermost layer of the topological laser resonant cavity respectively, the closed topological laser resonant cavity is formed at the interface of the area A and the area A ', and the area B is embedded in the middle of the interface; the three different photonic crystal regions have different primitive cell energy band characteristics, and the energy band structure of the photonic crystal primitive cell in the region B has a linear dispersion curve and can be described by a Dirac equation; and the photonic crystal primitive cells in the A'and the A region are energy band structures with different topological valley numbers obtained by breaking the symmetry of the photonic crystal primitive cells in the B region. According to the invention, the performance of the topological valley photonic crystal laser can be enhanced.

The invention discloses a double-resonant-cavity Q-switched laser, two resonant cavities which share a laser crystal and a Q-switched switch but have different cavity lengths are formed through a rotatable half-wave plate, and the polarization state of light is changed by rotating the half-wave plate, so that the light is converted between the two resonant cavities; under the condition that a gain medium or a device structure is not changed, half-wave plate rotation is provided, and pulse width conversion can be simply achieved.

The invention provides an all-solid-state high-power single-frequency laser based on an optical fiber-slab mixed structure, and relates to the technical field of solid lasers, and the all-solid-state high-power single-frequency laser comprises an all-solid-state continuous single-frequency seed module, an optical fiber pulse modulation module, an optical fiber pre-amplification module, a slab laser pre-amplification module, a slab laser main amplification module and a frequency multiplication module which are sequentially arranged; the lath laser pre-amplifier and the lath laser main amplifier are used for compensating thermally induced aberration generated by lath laser through multi-pass amplification designed according to the spherical aberration self-compensation principle, and then the quality of light beams is improved. In addition, a discrete mirror group is adopted to replace a complete amplifier cavity mirror, spontaneous radiation and parasitic oscillation in the working process of the amplifier are effectively restrained, nearly hundred mJ-magnitude single-frequency pulse laser with excellent light beam quality can be obtained, and application to laser radar detection or industry can be met.

The invention provides a dual-wavelength tunable all-solid-state mid-far infrared laser, relates to the technical field of lasers, and is used for solving the technical problems that high-performance dual-wavelength 3 [mu] m waveband laser and mid-far infrared waveband laser generated by pumping of the high-performance dual-wavelength 3 [mu] m waveband laser are difficult to obtain in the prior art. The middle and far infrared laser comprises an erbium-doped laser and an optical parametric oscillator, the erbium-doped laser is used for providing dual-wavelength 3-micron wave band pulse laser, and the erbium-doped laser comprises a pumping source, an erbium-doped laser medium, a gain modulator, a high reflective mirror and an output mirror; the optical parametric oscillator is used for obtaining medium-wave infrared laser and long-wave infrared laser which are output in a dual-wavelength mode under the pumping effect of the dual-wavelength pulse laser in the 3-micron wave band. The mid-far infrared laser is simple in structure and convenient to use, can obtain tunable dual-wavelength mid-far infrared pulse laser with high beam quality, and meets the light source requirements of differential absorption of toxic gas telemetering of laser radar and photoelectric countermeasure.

The invention discloses a method for generating high-quality Laguerre-Gaussian vortex light, which comprises the following steps: based on a V-shaped laser resonant cavity of a concave folded mirror, astigmatism is introduced by utilizing different convergence capacities of the concave folded mirror on a meridian plane and a sagittal plane of a light beam, so that the cylindrical symmetry of the resonant cavity is destroyed, and the high-quality Laguerre-Gaussian vortex light is generated; the influence of the cylindrical symmetry of the laser resonant cavity on the intrinsic mode of the cavity is eliminated, so that the intrinsic mode of the cavity is a Hermite-Gaussian mode, and the generation of an ellipse due-Gaussian mode is inhibited; an off-axis pumping method is adopted, and the laser resonant cavity generates high-order Hermite-Gaussian mode laser; the focusing lens focuses the generated high-order Hermite-Gaussian mode laser, so that the beam waist of the high-order Hermite-Gaussian mode laser is positioned in the center of the astigmatism mode converter; the astigmatism mode converter provides conditions for mode conversion by changing the Gouy phase of the laser mode, and high-quality Laguerre-Gaussian vortex light output is achieved.

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

The invention discloses an all-solid-state debugging-free slab laser based on an orthogonal Porro prism, and belongs to the technical field of solid laser. The diode stack array is used as a pumping source; the pumping shaping system performs homogenization shaping on the slow axis direction of the diode stack array; the coupling cavity mirror introduces the shaped light field into the lath laser crystal, and is used as an oscillation laser reflector at the same time; the ridges of the first Porro prism and the second Porro prism are mutually orthogonal; a light field introduced into the slab laser crystal reaches the first Porro prism through the polaroid, enters the coupling cavity mirror through the polaroid after being reflected, is subjected to repeated reciprocating oscillation on the end face where the coupling cavity mirror is located and the end face where the first reflector and the second reflector which are longitudinally arranged are located to reach the second Porro prism, and then returns to the first Porro prism along the original path; and the light is output by the polaroid. Large single pulse energy can be output based on a single resonant cavity, cascade amplification is not needed, the system size compactness is very high, and the photoelectric conversion efficiency is high.

The invention relates to a miniaturized medium-long wave infrared solid-state laser in which a thulium-doped laser directly pumps a ZGP crystal, the thulium-doped laser takes two laser diodes with the central emission wavelength of 793 nm as pumping sources, two Tm: YAP crystals with the same parameters are cascaded and placed in a U-shaped resonant cavity to serve as laser gain media, and an acousto-optic Q crystal controls intra-cavity loss in the resonant cavity, so that the thulium-doped laser directly pumps the ZGP crystal. Pulse laser with the wavelength of 1.94 m is output; the 1.94 m pulse thulium laser serves as pump light and passes through the ZGP-OPO module, and 2.8 m signal light and 6.2 m idler frequency light are obtained. The Tm laser outputs 1.94 m laser through primary oscillation to directly serve as a pump source, the ZGP-OPO outputs medium-long wave infrared laser in a nonlinear mode, the overall light path structure of the medium-long wave laser is simplified, and the electro-optical conversion efficiency is improved.

The invention relates to the technical field of all-solid-state laser, and provides a thermal stress self-matching laser device and a regulation and control method thereof. The resonant cavity oscillates the pumping laser, and an input lens and an output lens are oppositely arranged in the resonant cavity; the gain medium is arranged between the input lens and the output lens; the stress self-adaptive heat sink is used for dissipating heat and can monitor and adjust a real-time stress value borne by the gain medium; the power meter is arranged at the downstream of the output lens along the light path and is used for measuring the power of the output laser; a stress threshold value is preset in the processor; and the processor is used for controlling the stress adaptive heat sink to adjust the real-time stress value based on the power and the stress threshold value, so that the power meets a preset requirement. According to the invention, the stress of the gain medium in the operation process of the laser is monitored, regulated and controlled, and the stress matching of the gain medium is realized, so that the thermally induced stress damage risk of the gain medium is reduced.

The invention belongs to the field of optical parametric oscillators, and particularly discloses a cavity length control device and method for a femtosecond pulse synchronous pump optical parametric oscillator, and a temperature control element is arranged on a metal bottom plate and used for adjusting the temperature of the metal bottom plate; and the temperature controller is electrically connected with the temperature control element and is used for adjusting the temperature of the temperature control element according to the characteristic parameters of the light output by the optical parametric oscillator so as to adjust the temperature of the metal bottom plate to adjust the cavity length of the optical parametric oscillator. The temperature of the temperature control element is accurately adjusted through the temperature controller, fine control over the temperature of the metal bottom plate is achieved, then fine control over the length of the metal bottom plate is achieved, small changes of the length of the metal bottom plate can be directly reflected to changes of the cavity length, and therefore high-precision adjustment of the cavity length is achieved; and compared with expensive devices such as piezoelectric ceramics and precise stepping motors, the manufacturing cost and the maintenance difficulty are reduced, and meanwhile, the overall performance and stability of the system are improved.

The invention discloses a green laser and a laser welding machine. The green laser comprises a pumping source, a first reflector, a laser crystal, a polarization beam splitter, a second reflector, a frequency doubling crystal, a telescope lens group and a spectroscope; the pumping source provides pulse pumping light; the laser crystal absorbs the pulse pump light to generate fundamental frequency laser in an infrared band, the fundamental frequency laser enters the polarization beam splitter and is split into P polarized light and S polarized light, the P polarized light is transmitted out of the resonant cavity, and the S polarized light is transmitted in the resonant cavity; and the telescope lens group converges the fundamental frequency laser to the frequency doubling crystal to generate frequency doubling laser of a green light wave band, and the frequency doubling laser is transmitted by the spectroscope and then is output. The green laser is used for spot welding of high-reflection materials such as copper and aluminum, the maximum single pulse energy can reach 5 J, the maximum peak power is 2 kW, the pulse width ranges from 0.05 ms to 5 ms, the problem of low absorption of the high-reflection materials to laser in the 1-micron wave band is solved, and the green laser is an edge tool for precise spot welding of the high-reflection materials.

The invention belongs to the technical field of laser pulse modulation, and particularly relates to an ultrafast laser multi-pulse sequence preparation device and method. According to the invention, ultrafast pulse laser is divided into a transmission light path and a reflection light path through a beam splitter, a spatial light modulator is utilized to perform programming control on a target pulse in the transmission light path, and amplitude and pulse width parameters can be controlled while multiple pulse strings are generated; and the light path of the reflection light path is controlled through the high-precision one-dimensional displacement table, so that the time delay of a reflection light path pulse relative to a transmission light path pulse is controlled. And after the reflected light path and the transmission path subjected to pulse shaping are combined again, a periodic pulse string sequence with controllable time delay, pulse number, pulse width parameter and pulse intensity is realized. The problem that high-precision multi-pulse dynamic programming cannot be achieved through a traditional adjusting mode is solved, and the problems that in the prior art, the number of excitation pulses and pulse width parameters cannot be controlled at the same time, and an ordered periodic pulse sequence cannot be generated are solved.

The invention relates to a microsphere laser and a preparation method thereof, the microsphere laser comprises an optical fiber, microspheres and a pump light source, the microspheres are erbium-ytterbium co-doped microspheres containing erbium ions and ytterbium ions, the number of the microspheres is two, the microspheres are respectively a first microsphere and a second microsphere, the diameter of the first microsphere is smaller than that of the second microsphere, and the pump light source is arranged between the optical fiber and the pump light source. A conical area which is gradually shrunk from the two ends to the middle is arranged at the position, close to the center, of the optical fiber, the first end of the conical area is close to the pump light source, the second end of the conical area is far away from the pump light source, and the two microspheres are located on the upper side and the lower side of the conical area of the optical fiber respectively. The first microsphere is disposed proximate a first end of the tapered region to couple with a first end of the optical fiber, and the second microsphere is disposed proximate a second end of the tapered region to couple with a second end of the optical fiber. Through the arrangement form of the two microspheres, the optical fiber and the pump light source, the threshold value is reduced.

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 provides a low repetition frequency wide spectrum laser based on out-of-cavity broadening and an imaging system thereof.The laser comprises an ultrafast pulse generation long cavity, a spectrum broadening unit and a time domain stretching unit which are connected in sequence, and the ultrafast pulse generation long cavity is used for generating ultrafast pulses with low repetition frequency and high phase coherence; the spectrum broadening unit is used for carrying out spectrum broadening on the ultrafast pulse to obtain a low repetition frequency broadened pulse, and the time domain stretching unit is used for carrying out time domain stretching on the low repetition frequency broadened pulse to obtain low repetition frequency wide spectrum laser. When the low-repetition-frequency wide-spectrum laser is applied to an imaging system, the imaging speed, the longitudinal resolution and the imaging quality can be improved, and the broadband requirements of imaging on a detector and a data acquisition card are reduced.

A device for generating laser with ultra-narrow-linewidth includes an optical self-injection locking loop and an ultra-stable cavity phase-locked loop. The optical self-injection locking loop improves the quality factor of the laser resonator to narrow the linewidth. The ultra-stable cavity phase-locked loop locks the phase of the optical signal in the optical self-injection, synchronizing the laser frequency with the optical resonator. Through feedback control of the laser's driving current, it further reduces the laser's frequency noise and enhances the linewidth narrowing rate. Additionally, the ultra-stable cavity phase-locked loop provides stable control of the laser frequency, preventing mode hopping caused by laser frequency drift, thereby improving system stability. Therefore, this device can provide a stable narrow-linewidth laser source for applications in fiber optic communication, lidar, industrial device processing, and medical fields.

A grain-oriented electrical steel sheet according to an embodiment of the present disclosure includes: an electrical steel sheet substrate; and an insulating film layer that is disposed on the electrical steel sheet substrate. At least one deformation portion having a linear shape is formed on a surface of the electrical steel sheet substrate, and a natural corrosion potential value of the electrical steel sheet is -350 mV or more.

The invention discloses a method and system for generating an ultrafast pulse string with time-varying space-time characteristics, and relates to the technical field of laser pulse control, and the method comprises the following steps: after an incident light pulse is reflected by a first grating and collimated by a first cylindrical lens, the spectral component of the incident light pulse is expanded along the space on the plane where a phase plate is located; realizing time domain positive Fourier transform to form two-dimensional space-spectrum distribution; modulating a phase plate, and performing complex amplitude modulation on the two-dimensional space-spectrum distribution by using the phase plate to obtain a space-spectrum; the modulated space-spectrum passes through a second lens and a second grating to realize time domain inverse Fourier transform to obtain an output pulse; the output pulse is transmitted for a certain distance on the rear surface of the grating to form an ultrafast pulse string with time-varying space-time characteristics, time and space dimensions are regulated and controlled at the same time, more complex space-time characteristics are achieved, and time and space distribution of the pulse is accurately controlled.

The invention discloses a dual-wavelength microsphere laser based on tri-doped rare earth ions and a preparation method thereof, the dual-wavelength microsphere laser based on tri-doped rare earth ions comprises a silica fiber, the middle part of the silica fiber is provided with a conical region; the pump light source is arranged at one end of the silica fiber; the erbium, holmium and ytterbium tri-doped tellurate glass microspheres are arranged in the conical region; pump light emitted by the pump light source is guided to the conical region through the single-mode optical fiber and is optically coupled with the erbium-holmium-ytterbium tri-doped tellurate glass microsphere; in the erbium-holmium-ytterbium triple-doped tellurate glass microspheres, infrared-transmitting tellurate glass is used as a matrix, and the doping amount of an erbium element is 0.11%, the doping amount of a holmium element is 0.22%, and the doping amount of an ytterbium element is 0.80% in percentage by mass. According to the dual-wavelength microsphere laser based on the three-doped rare earth ions, efficient and stable dual-wavelength laser output is achieved.

The utility model relates to a light-gathering cavity for a large-energy laser and the laser. The light-gathering cavity comprises a cavity assembly, an inner end, a middle end, an outer end, a xenon lamp fixing piece and a glass tube. An accommodating channel for accommodating the xenon lamp and the laser crystal is formed in the cavity assembly; an inner end, a middle end and an outer end are sequentially arranged at the two ends of the cavity assembly in the extending direction of the two ends of the containing channel so as to seal the containing channel; the glass tube is arranged in the containing channel, the two ends of the glass tube are installed at the inner ends, a laser crystal is contained in the glass tube, and a crystal cooling channel is formed between the glass tube and the laser crystal. The outer end is used for hermetically connecting the laser crystal; the inner end head, the middle end head and the outer end head are respectively provided with a through hole for the xenon lamp to penetrate through, and the xenon lamp fixing piece is arranged on the outer side of the outer end head and used for connecting the xenon lamp and the outer end head in a sealed mode. A gap is formed between the through hole and the xenon lamp to form a xenon lamp cooling channel; and the middle end head is provided with an inlet and an outlet which are communicated with the crystal cooling channel and the xenon lamp cooling channel.

A first pumping source and a second pumping source are combined through a pumping beam combiner and are coupled into an erbium-doped fluoride fiber and a high-reflectivity fiber bragg grating, and the erbium-doped fluoride fiber and a low-reflectivity fiber bragg grating form a laser resonant cavity. The intermediate infrared laser is output through the low-reflectivity fiber bragg grating, the cladding light filter and the optical fiber end cap; the high-reflectivity fiber bragg grating and the low-reflectivity fiber bragg grating have the same grating period, the fourth-order harmonic reflection wavelength of the grating is located in the emission spectrum range of transition of erbium ions from the 4F9 / 2 energy level to the 4I9 / 2 energy level, and the fifth-order harmonic reflection wavelength of the grating is located in the emission spectrum range of transition of erbium ions from the 4I11 / 2 energy level to the 4I13 / 2 energy level; by adjusting the power of the first pumping source and the second pumping source, the net gain of laser transitions from the 4F9 / 2 energy level to the 4I9 / 2 energy level and transitions from the 4I11 / 2 energy level to the 4I13 / 2 energy level is regulated and controlled, and switching of laser working wavelengths is achieved.

The invention discloses three-wavelength output laser equipment and an implementation method thereof. According to the invention, a fundamental frequency laser is adopted to output fundamental frequency light with a fundamental frequency wavelength, a frequency multiplication module is adopted to multiply the fundamental frequency light into multiple frequency light, a first dichroic mirror and a second dichroic mirror are used in pairs, and the directivity of the frequency multiplication light and the fundamental frequency light after the frequency multiplication module is moved into a light path is ensured to be the same; the wavelength of the frequency-doubled light is converted into the oscillation-starting wavelength of the laser cavity through the laser cavity, the divergence angle of the frequency-doubled light is modulated by adopting the second lens, and the divergence angle of the laser of the oscillation-starting wavelength of the laser cavity is modulated by adopting the fourth lens, so that the directivity and the divergence angle of the output laser of different wavelengths are the same; therefore, after entering the light guide arm, the light with different wavelengths acts on the same position on the application terminal and has the same focusing performance. According to the invention, three kinds of lasers with different wavelengths can be respectively provided according to needs, and three lasers do not need to be prepared; according to the invention, the cost is reduced, and great convenience is brought to a user in use.

The present invention proposes a high-power nanosecond ultraviolet laser, which relates to the technical field of solid lasers, including a first pump source, a first pump mirror, a first gain crystal, a second gain crystal, a second pump mirror and a second pump source arranged in sequence along the light-emitting direction of the first pump source; the first pump light emitted by the first pump source is transmitted to the first gain crystal, the second gain crystal and the second pump mirror in sequence through the first pump mirror, the first pump light is reflected by the second pump mirror, so that the reflected light of the second pump mirror is transmitted to the Q-switched device and the first reflector in sequence, the second pump light emitted by the second pump source is transmitted to the second gain crystal, the first gain crystal and the first pump mirror in sequence through the second pump mirror, the second pump light is reflected by the first pump mirror, so that the reflected light of the first pump mirror is reflected to the second reflector; the reflected light of the second reflector is transmitted to the triple frequency crystal, the double frequency crystal and the third reflector in sequence, so that the triple frequency crystal outputs ultraviolet laser close to the end face of the second reflector. The present invention is helpful to improve the output power of ultraviolet laser.

The invention belongs to the technical field of light field modulation, and particularly relates to a light field modulation method based on a Fabry-Perot microcavity internal device. The method comprises the following steps: based on a micro-nano light processing scheme, constructing a Fabry-Perot microcavity laser based on intracavity low-light element light field shaping, and then placing the laser in a light field test system; the method comprises the following steps: (1) detecting an output laser pattern, and controllably constraining and modulating an intracavity light field by adjusting the position of a laser; (2) detecting an output laser spectrum, further adjusting the pumping energy to obtain a relation between a spectrum peak value and the pumping energy, and realizing high-quality factor single-mode laser; by designing the matching relation between the optical continuous interface or diffraction structure configuration and the micro-cavity configuration in the micro-cavity laser, the performance parameters of the Fabry-Perot micro-cavity and the modulation of the intra-cavity light field can be realized, so that the high-quality factor micro-cavity laser and the customized output of the light field in a specific laser mode are realized.

The utility model relates to the technical field of laser tubes, in particular to a multi-connected multi-section type carbon dioxide laser tube which comprises at least two laser tube bodies. The two adjacent laser tube bodies are connected end to end through a U-shaped tube; the two corners of the U-shaped tube are respectively provided with a first holophote, and the resonant cavities of the laser tube bodies are connected to be concentric through the first holophotes. N first electrode groups are mounted in the middle of the resonant cavity of each laser tube body, each first electrode group comprises two first electrodes, and n is greater than or equal to 1; the n first electrode groups divide the discharge distance of each laser tube body into n + 1 sections; and each section of discharge distance is coaxial and independently supplies power. According to the utility model, when laser with higher power is output, the striking voltage and the striking current of the laser tube can be reduced, and the breakdown proportion of the laser tube can be reduced.

The laser device (200) includes a mirror used as a partial reflector (6) that constitutes one end of the resonator (10). The mirror has an inner surface (6a) that is coated with a partial reflection coating for a specific wavelength or that is not coated with a partial reflection coating, and an outer surface (6b) that faces away from the inner surface (6a) and is coated with a total transmission coating for a specific wavelength. The inner surface (6a) is a curved surface having a center of curvature (O1) located on the optical axis (10a) of the resonator (10). The outer surface (6b) is a curved surface having a center of curvature (O2) that is offset from the optical axis (10a) of the resonator (10).

The invention discloses an unequal-arm Mach-Zehnder interferometer and micro-ring cascaded multi-channel output wavelength tunable laser. The unequal-arm Mach-Zehnder interferometer and micro-ring cascaded multi-channel output wavelength tunable laser comprises a chip; the spot size converter is arranged on the chip; the composite resonant cavity is connected with the spot size converter; the composite resonant cavity comprises a phase modulation arm connected with the spot size converter; the first unequal-arm Mach-Zehnder interferometer is connected with the phase modulation arm; a second unequal-arm Mach-Zehnder interferometer and a third unequal-arm Mach-Zehnder interferometer; and the annular resonant cavity is connected with the output end of the second unequal-arm Mach-Zehnder interferometer and the output end of the third unequal-arm Mach-Zehnder interferometer through waveguides. The invention is used for providing a laser with selectable output channel number and tunable output wavelength, the tuning range of the laser can reach 30nm, and the laser can be used for a dense wavelength division multiplexing system and can be used as a frequency modulated continuous wave laser radar light source.

The invention discloses a periodic forked near-transformation limit nanosecond pulse mode-locked fiber laser and a generation method. The laser is characterized in that a fiber ring cavity comprises a wavelength division multiplexer, an erbium-doped fiber, a first polarization controller, a polarization analyzer, a dispersion control unit, an output coupler, a fiber isolator and a second polarization controller which are sequentially connected in a closed loop mode. The method comprises the steps that pumping continuous light is coupled into the laser through the wavelength division multiplexer; pumping continuous light is absorbed by using an erbium-doped fiber and is stimulated to radiate a gain pulse with a long wave band, and the generated pulse oscillates in a fiber laser cavity; under the combined action of a first polarization controller, an analyzer and a second polarization controller, an equivalent saturated absorption effect is generated by utilizing nonlinear polarization rotation generated when gain pulses are propagated in an optical fiber, and pulse mode locking is realized; the optical fiber laser works in an abnormal dispersion region, so that generated pulses meet the soliton area theorem, and near-transformation limit pulses are generated. According to the invention, nanosecond pulse period bifurcation output of the short-cavity fiber laser can be realized.

A 1907nm single-mode polarization-maintaining all-fiber laser belongs to the field of optics. The present invention solves the problem of low output power of the existing polarization-maintaining single-mode thulium-doped fiber laser. It includes: a fiber oscillator and a fiber amplifier; a high-reflectivity fiber Bragg grating is sequentially connected to the first forward-pumped optical combiner, the first low-doped single-mode thulium-doped gain fiber and the low-reflectivity fiber Bragg grating, and the first pump light source is connected to the first forward-pumped optical combiner pump fiber; the output end of the low-reflectivity fiber Bragg grating is connected to the input end of the first cladding pump light stripper; the first cladding pump light stripper is sequentially connected to the optical isolator, the mode field adapter, the second forward-pumped optical combiner, the second low-doped single-mode thulium-doped gain fiber and the second cladding pump light stripper, and the second pump light source is connected to the second forward-pumped optical combiner pump fiber; the optical isolator pigtail outputs linearly polarized light on the slow axis; all devices are polarization-maintaining devices. The present invention is used for fiber lasers.

The invention discloses an air-cooled miniature slab laser based on double-end pumping, and belongs to the technical field of solid laser. Wherein the first conduction cooling single bar and the second conduction cooling single bar are arranged at the upper end and the lower end of the lath laser crystal in a staggered manner to form a double-end pumping structure; after the first fast axis collimation cylindrical lens and the second fast axis collimation cylindrical lens respectively collimate the fast axis directions of the first conduction cooling single bar and the second conduction cooling single bar, partial end surfaces are injected into the lath laser crystal; the first resonant cavity reflector and the second resonant cavity reflector are located at the left end and the right end of the lath laser crystal; the laser injected into the slab laser crystal passes through the resonant cavity mirror and then is subjected to multi-pass back-and-forth oscillation between the first resonant cavity reflector and the second resonant cavity reflector to reach the resonant cavity output cavity mirror. The output monopulse energy is greatly improved, the overall electro-optical efficiency is high, and the system compactness is high.