103 results about "Mid infrared laser" patented technology

The invention relates to the technical field of laser processing, and discloses a laser processing device and method suitable for TGV forming, and the method comprises the steps: S1, a glass substrate is scanned in a confocal manner, a three-dimensional topological graph is obtained, and the three-dimensional topological graph comprises the three-dimensional coordinate, the thickness gradient and the positioning mark of the glass substrate; s2, based on the three-dimensional topological graph, a through hole body is formed through ultraviolet femtosecond laser etching, and intermediate infrared laser is synchronously and dynamically controlled to etch the side wall of the through hole body to generate a taper through hole with a preset taper angle; and S3, the incident angle of the ultraviolet femtosecond laser is adjusted on the side wall of the taper through hole according to the three-dimensional topological graph, and a plurality of heat dissipation grooves are etched through the ultraviolet femtosecond laser. According to the laser processing device and method suitable for TGV forming, signal integrity optimization and active heat dissipation functions are achieved in the same through hole, the application range of the TGV is widened, and the stability of the TGV during use is improved.

The invention discloses an intelligent ground mobile high-precision gas leakage inspection and source tracking system, and relates to the technical field of gas pipe network leakage detection and leakage point positioning analysis. The system is mainly composed of a mobile inspection platform, a mid-infrared laser detection device, a three-dimensional anemograph, an inertial navigation module, a GIS system, a GNSS navigation positioning system, a wireless communication module and an intelligent detection comprehensive platform, and multi-source information fusion calculation, a dynamic adaptive analysis model and a maximum likelihood estimation method are combined. According to the intelligent gas leakage detection system, autonomous inspection can be achieved in a complex environment, abnormal gas component data can be processed in real time, detected gas space-time distribution information is transmitted to an intelligent comprehensive platform through a wireless communication module, data sharing and monitoring are completed, and efficient detection and accurate positioning of gas leakage are achieved. The method is suitable for gas leakage monitoring and component tracking in the fields of urban gas pipe networks, industrial parks and environmental protection, and the efficiency and precision of gas detection are remarkably improved.

The invention discloses a high-power intermediate infrared fiber laser. The fiber laser is composed of a first pumping source, a second pumping source, a pumping beam combiner, a high-reflectivity fiber grating, a low erbium-doped fluoride fiber, a low-reflectivity fiber grating, a cladding light filter, a fiber end cap, a collimating lens and a dichroscope. The mode of combining erbium ion ground state transition achieved through fiber core pumping and erbium ion excited state transition achieved through cladding pumping is adopted, mid-infrared laser upper energy level particle number accumulation is obtained, and meanwhile laser lower energy level particles are effectively consumed through the cladding pumping transition process. And the population inversion state of the laser system is kept, and the particle circulation rate and the quantum efficiency from the pump light to the intermediate infrared laser are improved, so that the generation of high-power and high-efficiency intermediate infrared fiber laser is realized.

The invention discloses an ultra-wide-band tunable intermediate infrared laser device and a light beam pointing stabilizing method. The device comprises a fundamental frequency pumping source, an ultra-wide tuning annular resonant cavity, a nonlinear frequency conversion crystal, a laser wavelength tuning controller and a light beam pointing stabilizing controller. The fundamental frequency pumping source is used for providing pumping laser for high-peak power pulse emission, the ultra-wide tuning annular resonant cavity adopts a special special-shaped angle design, a high-refractive-index intrinsic substrate is used as an input and output coupling mirror, and the pumping laser enters the high-refractive-index intrinsic substrate at a Bronsted angle and enters the resonant cavity through coupling of the high-refractive-index intrinsic substrate; at least two cavity mirrors in the resonant cavity mirror are gold mirrors highly reflecting near-infrared and middle-infrared bands, the pump light passes through the nonlinear frequency conversion crystal and forms a closed-loop light path in the resonant cavity, efficient optical parametric oscillation is achieved, and middle-infrared laser with an extremely wide wavelength tuning range is generated. And the light beam pointing stabilization controller controls the resonant cavity mirror to compensate light beam pointing deviation, so that continuous wavelength tuning is realized, and the light beam pointing is kept unchanged.

The invention provides a high-speed large-capacity intermediate infrared laser communication method and system based on an integrated waveguide, and is mainly used for solving the problems that when an existing space laser communication system adopts intermediate infrared band transmission, a frequency conversion scheme based on a block material is poor in phase matching, large in size, low in conversion efficiency, low in cost and the like. And the actual requirements of high-speed and large-capacity communication are difficult to meet. According to the high-speed large-capacity mid-infrared laser communication method based on the integrated waveguide, the first integrated waveguide is adopted to realize conversion from a near-infrared band to a mid-infrared band frequency comb, the wavelength division multiplexing technology is combined to maximize the channel capacity, and then the second integrated waveguide is adopted to restore a near-infrared band optical signal. The problems of insufficient capacity, generation of attenuation and loss, low rate and the like when near-infrared band optical signals are transmitted in an atmospheric channel are avoided, space laser communication with the rate of Tbps magnitude is realized, an optical field can be restrained in a micro-nano waveguide structure to the greatest extent, and the frequency conversion efficiency is improved.

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 provides an efficient OPO system with a bicrystal compensation and independent pumping regulation and control structure, and relates to the technical field of laser nonlinear frequency conversion. The device comprises a pump laser, a light source regulation and control unit, an incidence adjustment unit, an OPO resonant cavity and an output separation unit which are sequentially arranged, the OPO resonant cavity comprises a walk-off compensation and frequency conversion module and a tuning module, and the walk-off compensation and frequency conversion module comprises a nonlinear crystal I and a nonlinear crystal II which have opposite cutting angles. And a tuning module is arranged between the nonlinear crystal I and the nonlinear crystal II. The OPO system based on the bicrystal structure has space walk-off angle compensation and pump light independent regulation and control capabilities, and is suitable for constructing near-infrared and intermediate-infrared laser sources with high efficiency and high stability. According to the invention, the optical path structure is flexible, the multi-crystal and multi-band adaptation is supported, and the system compatibility is good; miniaturization and intelligent integration are easy, and industrial application and popularization are facilitated.

The invention discloses a dynamic early warning method for a high-sulfur-content natural gas leakage influence range in the field of leakage gas monitoring. The method comprises the following steps: arranging an intermediate infrared laser remote measurement system in a high-sulfur-content natural gas field to monitor the concentration of hydrogen sulfide gas in the gas field in real time; judging whether the gas field is leaked or not according to the concentration of the hydrogen sulfide gas, if so, executing the next step, otherwise, repeating the judgment; calculating leakage flow and leakage hole radius; and substituting the leakage hole radius and the leakage flow into the optimized time sequence Gaussian smoke cloud model to obtain the concentration values of the hydrogen sulfide gas at different moments and different spatial positions, namely the influence ranges of the leakage gas at different moments. According to the method, the size of the leakage hole can be calculated, the dynamic correction process of the three-dimensional leakage range of the Gaussian model is completed, various conditions of mixed gas leakage factors are considered at the same time, and the dynamic calculation process of the influence range of the leakage gas is achieved.

The invention discloses a microphone device and method capable of locating a sound source and a digital human device.The device comprises a plurality of basic units and a signal processing module, and each basic unit is composed of pickup microphones annularly and evenly arranged at intervals and an infrared laser distance measuring sensor located in the center; the plurality of basic units are arranged to form a ranging microphone array matrix. The signal processing module synchronously collects a sound signal of the pickup microphone and a distance signal of the infrared laser distance measuring sensor, and firstly processes the sound signal based on a TDOA algorithm to obtain a two-dimensional plane coordinate of a sound source; and positioning a corresponding basic unit according to the two-dimensional plane coordinate, calling a distance signal of an infrared laser distance measuring sensor in the unit, calculating a vertical distance between the sound source and the array matrix in combination with the two-dimensional coordinate, and finally determining a three-dimensional coordinate of the sound source. According to the invention, high-precision sound source three-dimensional positioning is realized.

The invention discloses a fuel gas leakage detection system based on mid-infrared laser, relates to the technical field of fuel gas detection, and aims to solve the problems that a large-area region is difficult to cover quickly and only close-range detection can be carried out in an existing laser fuel gas leakage detection method. The gas leakage detection system comprises a laser emission module, an infrared imaging detector module and a data processing module, the laser emission module is used for emitting an intermediate infrared laser beam to a to-be-detected area; the infrared imaging detector module is used for collecting an infrared spectrum signal of the to-be-detected area in real time; the infrared spectrum transmitting module is used for transmitting the infrared spectrum signal to the data processing module; and the data processing module is used for processing the received infrared spectrum signal to obtain a gas leakage detection result of the to-be-detected area. The method is suitable for detecting gas leakage in a natural gas pipeline and a liquefied petroleum gas storage tank area.

A mid-infrared laser generating system based on dispersion regulation and control soliton group pulses can obtain high-power, high-efficiency and high-proportion mid-infrared laser output, and has the advantages of being all-fiber, compact in structure and high in mid-infrared rear spectrum power proportion. The pulse fiber laser generates nanosecond pulse laser in a 1.5-micron wave band; the optical fiber pulse stretcher is a single-mode quartz optical fiber, the nanosecond pulse is split into a plurality of ultrafast soliton pulses through a nonlinear effect, and spectral energy conversion from 1.5 microns to 2.4 microns is carried out; the fiber laser amplifier further improves the output power of the broadened pulse laser, expands the spectrum to a 2.7-micron wave band, and improves the pulse energy after the 2.3-micron wave band; the optical fiber mode field adapter efficiently couples the pulse generated in the optical fiber laser amplifier into the nonlinear optical fiber; the nonlinear optical fiber expands the laser to a mid-infrared 3-5 micron wave band, and mid-infrared laser output with high power, high efficiency and high proportion is obtained.

The invention discloses a 2-micron-waveband adjustable all-fiber high-repetition-frequency pulse light source generator, belongs to the technical field of laser light source manufacturing, and aims to solve the problem that an existing 2-micron-waveband passive all-fiber mode-locked pulse laser light source is difficult to give consideration to fs-magnitude narrow pulse width and ultra-short-cavity-length high-fundamental-frequency repetition frequency output. The laser comprises a semiconductor laser pumping source, a wavelength division multiplexer, an extrusion type polarization controller I, a polarization-maintaining highly-doped gain fiber, an extrusion type polarization controller II, a long cone region tapering micro-nano fiber, a 2 * 2 fiber coupler and a fiber Faraday mirror. According to the invention, the long-cone micro-nanofiber is introduced into the cavity, and the long-cone micro-nanofiber has the characteristic of high nonlinear coefficient, so that the cavity length can be greatly shortened, enough nonlinear phase shift can be accumulated, and fs-magnitude ultrashort pulse can be output. The device is low in loss, stable in performance and easy to integrate with other optical fiber systems. The laser can be applied to the fields of optical communication, non-metallic material processing, laser medical treatment, intermediate infrared laser pumping sources and the like.

The invention belongs to the technical field of laser, and discloses a method and system for generating mid-infrared laser based on soliton self-frequency shift, and the method comprises the steps: obtaining a 2 [mu] m ultrashort pulse laser pumping source, a forward pumping source and a reverse pumping source; coupling the obtained 2-micron ultrashort pulse laser pumping source and the forward pumping source to a first end of a gain fiber, and coupling the obtained reverse pumping source to a second end of the gain fiber; adjusting the ratio of the pumping power of the forward pumping source in the first end of the gain optical fiber to the pumping power of the reverse pumping source in the second end of the gain optical fiber, and exciting the 2-micron ultra-short pulse laser pumping source in the gain optical fiber to generate soliton self-frequency shift to obtain wide-spectrum ultra-short pulse laser; and inputting the broad-spectrum ultrashort pulse laser into a filter for wavelength filtering treatment to obtain 2.8 [mu] m intermediate infrared laser. By adjusting the pumping power of the pumping sources at the two ends of the gain fiber, various different soliton self-frequency shift effects can be obtained.

The invention provides a mid-infrared optical frequency comb. The mid-infrared optical frequency comb comprises a near-infrared optical frequency comb seed source of a polarization-maintaining all-fiber structure; the all-fiber nonlinear amplification and pulse compression module is connected with the near-infrared optical frequency comb seed source through a polarization maintaining fiber and is used for amplifying the power of the seed light and compressing the pulse width after generating a linear chirped pulse; the all-fiber nonlinear spectrum broadening module is connected with the all-fiber nonlinear amplification and pulse compression module through a polarization maintaining fiber and is used for broadening a laser spectrum; the difference frequency module is used for receiving the laser pulse processed by the all-fiber nonlinear spectrum broadening module and generating an intermediate infrared laser pulse through intra-pulse self-difference frequency; wherein the seed source, the all-fiber nonlinear amplification and pulse compression module and the all-fiber nonlinear spectrum broadening module are connected through a polarization maintaining fiber to form an all-fiber integrated structure. By adopting the scheme, the anti-interference capability of the system can be enhanced, miniaturization and high operation reliability are realized, the debugging process is simplified, and the difference frequency efficiency is improved.

The mid-infrared optical parametric oscillator pumped by the dual-wavelength nanosecond pulse solid laser can simultaneously output 1.9 micron laser and 2.1 micron laser, realizes broad spectrum / multi-wavelength output of the mid-infrared optical parametric oscillator, and can ensure that mid-infrared laser has excellent beam quality and relatively high output power. The output power of the 1.9 [mu] m optical fiber laser pumping source is hectowatt magnitude, and the 1.9 [mu] m optical fiber laser pumping source serves as a pumping source of a Ho crystal in the solid laser oscillator. In a Tm solid laser oscillator and a Ho solid laser oscillator, a resonant cavity comprises two plano-concave sub-cavities, the two plano-concave sub-cavities are a Tm crystal oscillation cavity and a Ho crystal oscillation cavity respectively, the two plano-concave sub-cavities share one output mirror, the Tm crystal oscillation cavity adopts a 793 nm semiconductor laser for pumping, and the Ho crystal oscillation cavity adopts a 1.9 [mu] m optical fiber laser pumping source I for pumping; in the phosphorus-germanium-zinc optical parametric oscillator, a planar four-mirror annular cavity is used as a single-resonance optical parametric oscillation cavity.

The application provides a high-sensitivity multi-gas real-time monitoring device and method, which comprises a controller, wherein the controller is connected with a main control circuit; the main control circuit is connected with an indicating laser and a mid-infrared laser array; the indicating laser and the mid-infrared laser array are connected with a multi-pass gas cell through a fiber coupling structure; a photoelectric detector is arranged on the light outlet side of the multi-pass gas cell; and the photoelectric detector is connected with the main control circuit; the controller generates modulation signals with different frequencies to modulate the mid-infrared laser array; the indicating laser emitted by the indicating laser and the mid-infrared laser emitted by the mid-infrared laser array are coupled into a coaxial light beam through the fiber coupling structure and enter the multi-pass gas cell; the photoelectric detector collects signals with target gas information passing through the multi-pass gas cell and simultaneously analyzes the concentrations of multiple target gases through a signal conditioning algorithm. The application has the characteristics of high sensitivity, low detection limit, real-time monitoring, convenient installation, strong anti-interference ability, maintenance-free and wide application range.

The application relates to the field of laser technology, in particular to a device and a method for generating wide-tuning narrow-line-width mid-infrared laser, wherein the pump light emitted by a nanosecond pulse OPO base frequency pump source is reflected to a beam splitter by a full reflection mirror after passing through a first adjuster; the pump light emitted by a continuous wave OPO base frequency pump source is irradiated to the beam splitter after passing through a second adjuster; the two beams of pump light are combined after passing through the beam splitter, are focused after passing through a plano-convex lens, are irradiated to a first plano-concave full reflection mirror, and then are transmitted to a nonlinear crystal to generate signal light and idler mid-infrared laser through nonlinear frequency conversion; the idler mid-infrared laser and the residual pump light are transmitted to a doublet mirror and are separated by the doublet mirror; the signal light is reflected to the nonlinear crystal in sequence through a second plano-concave full reflection mirror, a first plane full reflection mirror, a second plane full reflection mirror and the first plano-concave full reflection mirror, and an oscillation closed loop is formed. The application realizes that the pulse OPO outputs a pulse with a line width less than 90 MHz in the tuning range, and the extraction efficiency of the idler light is as high as 9.3%.

The invention belongs to the technical field of laser materials and preparation thereof, and particularly relates to a mid-infrared 2.9 mu m wave band enhanced fluoride laser crystal and a preparation method and application thereof, the chemical composition of the crystal is any one of xHo, yA, zB: Ae1F2 or xHo, yA, zB: Ae1Ae2F4, ho < 3 + > ions are used as active ions, A < 3 + > ions are used as deactivation ions of the Ho < 3 + > ions, and B < 3 + > ions are used as structure regulation ions; 0.5 < = x < = 1.5 at.%, 0.05 < = y < = 0.15 at.%, and 1 < = z < = 30 at.%; the crystal structure belongs to a cubic system, and the space group is Fm-3m (225). Compared with the prior art, the crystal can realize higher luminous intensity in a 2.9 mu m wave band, realizes reversion of fluorescence intensity relative to a 1.9 mu m wave band, has better crystal quality and higher-power intermediate infrared laser output capability, and has the advantages of high gain bandwidth, high gain section, high power, high slope efficiency and the like in an intermediate infrared wave band.

The application relates to a high-power mid-infrared optical parametric oscillation amplification device directly pumped by a Tm laser, and belongs to the technical field of high-power mid-infrared lasers. The device comprises a Tm:YLF seed laser, a Tm:YLF slab amplifier, a ZGP optical parametric oscillator and a ZGP optical parametric amplifier in sequence. The Tm:YLF seed laser outputs 1.908-micron fundamental light, the power of the 1.908-micron fundamental light is amplified through the Tm:YLF slab amplifier, and then the ZGP optical parametric oscillator and the ZGP optical parametric amplifier are directly pumped. The injection end and the output end of the Tm:YLF slab amplifier are both provided with a fundamental light coupling isolation system. A mid-infrared laser coupling isolation system is arranged between the ZGP optical parametric oscillator and the ZGP optical parametric amplifier. The ZGP optical parametric oscillator and the ZGP optical parametric amplifier are directly pumped by high-power Tm:YLF lasers, so that the power of the mid-infrared laser and the overall efficiency of the system are improved.

The invention provides a medium-wave infrared and long-wave infrared band tunable dual-wavelength laser generation device and method, which are applied to the technical fields of medium-infrared laser generation, multiband photoelectric countermeasure, multi-component gas monitoring and the like. The device comprises an input mirror used for transmitting linear polarization pulse pump light of a first wavelength generated by a laser to a medium-wave infrared nonlinear crystal, wherein the medium-wave infrared nonlinear crystal is excited by the linear polarization pulse pump light to generate first-order signal light of a second wavelength and medium-wave infrared laser of a third wavelength; the medium-wave infrared output mirror is used for reflecting the first-order signal light to the total reflection mirror and transmitting and outputting medium-wave infrared laser; the total reflection mirror is used for reflecting the first-order signal light to the long-wave infrared nonlinear crystal, and the long-wave infrared nonlinear crystal is excited by the first-order signal light to generate second-order signal light with a fourth wavelength and long-wave infrared laser with a fifth wavelength; and the long-wave infrared output mirror is used for reflecting the second-order signal light to the input mirror and transmitting and outputting long-wave infrared laser.

The invention provides a method for generating high-peak-power intermediate infrared ultrafast laser based on pulse / continuous wave system parametric conversion. Comprising a pumping source 1 which is used for providing mu J-level energy and 10ps-level pulse width near-infrared pulse laser. Pump light is focused and subjected to path adjustment through the high reflectors 2, 3 and 5 and the lens 4, the pump light and signal light are combined through the dichroscope 15, and optical parametric conversion is carried out through the nonlinear crystal 16. Comprising a signal source 6 which is used for providing near-infrared continuous waves, signal light power and polarization direction are accurately regulated and controlled through an erbium-doped optical fiber amplifier 7, an attenuator 8, a polarization maintaining optical fiber circulator 9, a collimator 10 and a half-wave plate 11, and focusing and path adjustment are carried out through a lens 12 and high reflectors 13 and 14. Comprising a dichroscope 17 and long-pass filters 18 and 19 and is used for filtering out mid-infrared laser.

The invention discloses a light spot detection, adjustment and tracking element based on an intermediate infrared detector array, which comprises a TO-can TO8 base, a detector gasket, 12 independent intermediate infrared detector units and a tube cap, and the detector units are bonded on the detector gasket through elargol according to a specific arrangement mode. The 12 detector units are arranged in a specific geometric layout to form various arrays. When light irradiates the detector unit array, each detector unit can receive different light beam intensities according to different positions of the cross section of a light spot and generate corresponding electric signals, and the electric signals accurately reflect information such as the diameter, the center position, the intensity distribution, the moving direction and the moving speed of the light spot. Therefore, the method can be widely applied to various application scenes needing to accurately measure the size, the position or the motion of the light spot and the like. Therefore, the engineering requirements of light spot analysis, adjustment and tracking during collimation of the intermediate infrared laser beam can be met.

The application provides a niobium phosphate nonlinear optical crystal and preparation and application thereof. 12 Nb3P7O 31 , belongs to an orthorhombic system, a space group is Pna21, is a non-central symmetric structure, cell parameters are: a=0.5 nm, b=1.0 nm, c=0.5 nm, and Z=4, has a large nonlinear optical effect (3xKDP), is phase-matched, a theoretical indirect band gap is 5.11 eV, has a large laser damage threshold, a wide transmission range, stable physical and chemical properties, good mechanical properties, is not easy to deliquesce, and is easy to preserve, and can be used as a ferroelectric crystal, a pyroelectric crystal or a laser substrate material, and is widely applied in preparation of middle infrared laser nonlinear optical composite functional devices, piezoelectric devices, laser frequency conversion devices and the like.

The invention relates to the field of chemical oxygen-iodine lasers, in particular to a mid-infrared wavelength conversion method and device of a chemical oxygen-iodine laser. Firstly, a pair of pulsed magnetic field generators is placed on the upper side and the lower side of a gain area of an original continuous wave chemical oxygen-iodine laser; the hydrogen Raman pool is used as a magnetic gain switch to enable the laser to output laser pulses with higher peak power, then 1315nm wavelength laser output by the oxygen-iodine chemical laser is guided into the hydrogen Raman pool, the original 1315nm wavelength laser is converted into 2900nm wavelength laser through Raman scattering to be output, finally, the 2900nm wavelength laser is guided into the vacuum bin containing the iron-doped zinc selenide crystal, and the iron-doped zinc selenide crystal is obtained. And by pumping the iron-doped zinc selenide crystal, the laser with the wavelength of 2900 nm is further converted into intermediate infrared laser pulses with the wavelength of 4000-5000 nm. On the premise that the original laser structure is not influenced, the oxygen-iodine chemical laser has the possibility of being applied to the middle infrared band.

This application provides a cavity-enhanced mid-infrared photothermal vibration measurement system and method, relating to the field of photothermal vibration spectrum detection of materials, aiming to improve the accuracy and sensitivity of detection. The measurement system includes a cavity-enhanced substrate, a mid-infrared laser, a laser vibrometer, and a lock-in amplifier. The cavity-enhanced substrate includes a substrate and an asymmetric Fabry-Perot resonator. The asymmetric Fabry-Perot resonator includes a reflective layer, an intermediate dielectric layer, and a layer to be tested, sequentially stacked on the substrate. The mid-infrared laser applies mid-infrared laser light to the layer to be tested, causing the layer to generate a photothermal vibration signal. The laser vibrometer detects the photothermal vibration signal and converts it into a detection electrical signal. The lock-in amplifier extracts the detection electrical signal to determine the photothermal vibration spectrum of the layer to be tested. The ratio of the thickness of the intermediate dielectric layer to the thickness of the layer to be tested ranges from 0.8 to 10. The refractive index of the material of the layer to be tested is less than the refractive index of the material of the intermediate dielectric layer, but greater than the refractive index of air.

The invention discloses an automatic calibration gas detection system and calibration method based on cooperation of mid-infrared light and visible light, and relates to the technical fields of optical detection, environmental monitoring, automatic control and the like, mid-infrared laser and visible laser are combined and emitted into a multiple reflection pool, and initial alignment is carried out based on visible laser of indicating light in an initial state; a high-reflectivity mirror bracket of the multiple reflection pool is provided with a stepping motor used for adjusting the angle of a high-reflectivity mirror, in the operation process, the signal intensity and the signal-to-noise ratio are monitored in real time, the stepping motor is driven to adjust the angle of the high-reflectivity mirror according to the monitoring result, and closed-loop automatic calibration is achieved. According to the invention, the invisible mid-infrared light path is visualized by using coaxial indicating light, so that the calibration time of initial installation and daily maintenance is shortened, the angle of the high-reflectivity mirror is automatically adjusted, the offset of the light path is compensated and the optimal detection state is kept during the operation of the system, and the long-term stability and reliability of the system are improved.

The application provides a 2.8 mu m single-frequency fiber laser based on a pump-enhanced saturable absorber and belongs to the technical field of mid-infrared laser. The linear resonant cavity of the laser is composed of a low-refractivity fiber grating and a high-refractivity fiber grating, and a first pump coupler, an erbium-doped fluoride gain fiber, a pump light stripper and a pump-enhanced saturable absorber filter device are sequentially arranged in the cavity. The filter device contains enhanced pump light injected by a second pump source through a second pump coupler and used for exciting the absorption characteristics of the erbium-doped saturable absorption fiber; the laser of the first pump source is used for pumping the gain fiber to generate laser oscillation, and the enhanced pump light is used for forming a MHz-level ultra-narrow band dynamic grating in the saturable absorption fiber. The dynamic grating and the static filter of the fiber grating work cooperatively to realize stable single-longitudinal-mode selection, and finally the single-frequency laser is output from the first fiber end cap. The application realizes compact structure and high stability of 2.8 mu m single-frequency laser output.

A narrow linewidth mid infrared laser, including a pumping laser diode with a fast-axis compressor and a pumping wavelength λo; and an optical resonator arranged to receive the pumping wavelength λo, the optical resonator including a laser crystal with a lasing wavelength λp, a dichroic mirror, and a nonlinear crystal to generate an idler wavelength λi.

The invention relates to a thulium-zirconium co-doped gadolinium scandate near-middle infrared band laser crystal and a preparation method and application thereof, the chemical composition of the crystal is represented as TmxZryGd1-xSc1-yO3, the value range of x is more than or equal to 0.001 and less than or equal to 0.05, the value range of y is more than or equal to 0.005 and less than or equal to 0.05, and the space group of the crystal is Pnma and an orthorhombic system. The preparation method of the thulium-zirconium co-doped gadolinium scandate near-middle infrared band laser crystal is an edge-defined film-fed crystal method. Compared with the prior art, the laser crystal provided by the invention can efficiently realize output of near-middle infrared band laser near 1.5 microns and 2.3 microns, and can be applied to the fields of laser medical treatment, environmental monitoring, realization of output of near-middle infrared laser as an optical parametric oscillation (OPO) pumping source and the like.

An atomic force microscope-based nanoscale photothermal ion in-situ characterization device, comprising: an atomic force microscope module comprising an AFM conductive probe in contact with a to-be-measured region of a to-be-measured sample; a nanometer infrared photothermal excitation module for emitting pulsed mid-infrared laser to the to-be-measured region to cause the micro-cantilever of the AFM conductive probe to deform; a photothermal ion signal detection module comprising a signal detection unit and a data processing and display unit in communication, the signal detection unit being used to acquire the micro-cantilever signal of the AFM conductive probe; wherein the data processing and display unit acquires the photothermal ion second-harmonic signal of the to-be-measured region based on the micro-cantilever signal of the AFM conductive probe to display the image of the ion transport micro-region surface distribution of the to-be-measured region.