53 results about "Grating spectrometer" patented technology

The invention provides a multi-source fusion spectrum cross-domain high-precision prediction method and system based on transfer learning. The method comprises the following steps: S1, acquiring spectrograms collected by a spectral imaging device under multiple wavelengths; s2, extracting various types of features from the spectrogram; s3, training a fusion model to obtain a trained fusion model; and S4, inputting a to-be-predicted spectrum into the trained fusion model, and outputting a result. According to the invention, 10 <-4 > nm-level wavelength prediction can be achieved in a common industrial camera system, and the level of a scientific research-level grating spectrometer (0.001-0.002 nm) can be reached / exceeded; on a narrow-band, middle-band and wide-band multi-scene cross-domain data set, the mean absolute error (MAE) can be reduced from the nanoscale to the magnitude of 10 <-4 > nm, and excellent robustness is kept under the conditions of noise, feature deficiency and few samples.

The invention discloses a method and device for quickly switching multiple working modes of a grating spectrometer, and the method comprises the steps: 1, laying a grating and a detector on a working turntable, and adjusting the grating and the detector to be concentric and coaxial; and step 2, rotating the working turntable and the grating respectively, adjusting different incident angles of the grating and adjusting the angle of the detector to match the working wave band. The grating, the camera system and the detector are mounted on the same rotary table, so that the consistency of an optical system in the mode switching process is ensured, and the grating, the camera system and the detector are ensured to be coaxial in the working mode switching process. The mode that the rotary table rotating motor drives the rotary table to rotate as a whole and the grating rotating motor drives the grating to rotate independently is combined, rapid switching of multiple working modes of the grating spectrometer is completed, and broadband wavelength coverage of the grating spectrometer with multiple exposure combined is achieved.

The invention provides a slit-type spectral imaging method based on filtering phase reconstruction and a grating spectrometer. The method comprises the following steps: measuring wavefront aberration of a slit-type grating imaging spectrometer before slit filtering by using a wavefront sensor; based on a slit filtering principle, reconstructing a phase function after slit filtering by using wavefront aberration before slit filtering; and capturing a slit image, and reconstructing the slit image by using the reconstructed filtered phase function of the slit to obtain a final reconstructed image. According to the method, effective recovery of the slit imaging data of the grating spectrometer based on the slit is realized, the influence of optical aberration and image noise on the spectrum and spatial resolution of the spectrometer is effectively eliminated, and the slit imaging quality is remarkably improved and is close to the diffraction limit.

The invention provides a system and method for eliminating secondary diffraction spectrum influence of a grating spectrum system, and belongs to the field of grating spectrums.The eliminating system comprises a second filter, a third filter and double slits, the second filter and the third filter correspond to one slit in the double slits respectively, and the second filter and the third filter correspond to the other slit in the double slits respectively. The central wavelength and the passband width of the second filter plate and the third filter plate are matched with the slit distance of the double slits, separation of a second-level diffraction spectrum and a first-level diffraction spectrum is realized by utilizing the matching and design of the double slits and the optical filters, and the influence of the second-level diffraction spectrum of the grating spectrometer is eliminated. According to the invention, an optical filter does not need to be used for suppressing a secondary spectrum, so that the transmittance of the system is improved, the reflected light of the detector protection glass cannot be reflected by the optical filter to form relatively strong stray light, and the stray light formed by secondary diffraction light is reduced.

The invention discloses an optical sensing system based on double Fabry-Perot cavities. The optical sensing system comprises a laser module, a main light path module and a reference light path module, wherein the laser module is used for generating two laser beams which respectively enter a main light path and a reference light path; the reference light path module is used for providing a light source fluctuation reference signal for noise compensation; the main light path module comprises a double Fabry-Perot cavity sensing unit, a total reflection mirror, a focusing lens, a grating spectrometer, an optical detector and a signal processing unit. A double-Fabry-Perot cavity sensing unit in the main light path module adopts a novel micro-hemisphere double-cavity interference structure, and temperature and pressure changes are tested in combination with a synchronous resolving method. According to the technical scheme provided by the invention, the synchronous high-precision measurement of the temperature and the pressure can be realized by optimizing the structural design of the cavity, deepening the coupling effect of the gas medium and the physical quantity and introducing a high-precision decoupling algorithm and a noise suppression mechanism, and the application requirements of complex and harsh scenes are met.

The invention provides an exhaled gas synchronous detection device and method based on an aliasing spectrum model, and relates to the technical field of exhaled gas detection. The device comprises an LED broadband light source, a band-pass filter, a collimating lens combination, an optical resonant cavity, a converging lens, an optical fiber, a grating spectrometer, a detector and an upper computer. Infrared light emitted by the LED broadband light source sequentially passes through the band-pass filter, the collimating lens combination, the optical resonant cavity, the converging lens, the optical fiber and the grating spectrometer to form a composite light signal, the detector converts the composite light signal into an aliasing spectrum signal, and an exhaled gas synchronous detection method based on an aliasing spectrum model is integrated in the upper computer. The aliasing spectrum model carries out decoupling analysis on aliasing spectrum signals. According to the technical scheme, the problems that in the prior art, when ethyl alcohol and n-pentane are synchronously detected, aliasing interference of adjacent spectral lines is likely to happen, and the detection cost is high are solved.

This invention discloses a downconversion fluorescence thermometry method based on bilinear mode, implemented using a hardware system. The hardware system includes a 280nm light-emitting diode, two convex lenses, and a Tb... 3+ :Cs2Na 0.9 Ag 0.1 The system comprises InCl6 temperature-sensing material, a grating spectrometer, an oscilloscope, a signal generator, a computer, and a thermostat. The specific implementation steps are: signal excitation and acquisition; temperature calibration; actual temperature measurement; and high measurement accuracy: VPR mode linear correlation coefficient R² ≥ 0.998, FL mode linear correlation coefficient R² ≥ 0.992, avoiding measurement errors introduced by the exponential bias or correction term of traditional FIR technology, thus fundamentally improving temperature measurement accuracy.

The utility model provides a high-frequency monochromator, which is characterized by comprising a spectrograph and a scanning emitting mechanism, and the scanning emitting mechanism is loaded after the spectrograph emits a light beam. An entrance slit, a spectrograph, a field diaphragm, a collimation optical assembly, a rotary reflector or a rotary reflector with a grating light splitting function, a convergence imaging assembly and an exit slit are sequentially arranged along a light path, and light is emitted through the field diaphragm and the exit slit to form an L-shaped light path; the entrance slit, the spectrograph, the field diaphragm, the collimation optical assembly, the rotary reflecting mirror or the rotary reflecting mirror with the grating light splitting function, the convergence imaging assembly and the exit slit are all vertically fixed to the horizontal plane, and the rotary reflecting mirror or the rotary reflecting mirror with the grating light splitting function is arranged at the switching position of the L-shaped light path; the monochromator is simple in light splitting structure and efficient in light splitting.

This invention discloses a plasma local current measurement device and method based on optical methods, belonging to the field of optical measurement technology. The device includes: a high-energy pulsed laser, a beam splitter, a photodiode for triggering an ICCD camera, a beam sampling mirror for providing optical signals to the photodiode, a focusing lens for focusing the high-energy pulsed laser, a pulsed power device for generating Z-pinch plasma, a beam collector, an achromatic lens for collecting scattered light, a reflective grating spectrometer, an ICCD camera, and a Mach-Zehnder interferometer. Electron density distribution, electron temperature, ion temperature, plasma velocity, and relative electron-ion drift velocity can be simultaneously obtained through plasma interference fringe images and Thomson scattering spectra. The local current at the measurement point is obtained by multiplying the electron density, electron charge, and relative electron-ion drift velocity at the measurement point.

A synchronous measurement apparatus for a near-infrared spectrum and a Raman spectrum. The apparatus comprises a near-infrared spectrometer (1), a first optical fiber patch cord (2), a first optical fiber adapter (3), a collimating lens (4), a sample platform (7), a coupling lens (8), a second optical fiber adapter (9), a second optical fiber patch cord (12), a laser device (15), a third optical fiber patch cord (13), a Raman probe (10), a fourth optical fiber patch cord (14), a grating spectrometer (16) and a controller (17), wherein the first optical fiber patch cord (2) is connected to the near-infrared spectrometer (1) and the first optical fiber adapter (3); the second optical fiber patch cord (12) is connected to the near-infrared spectrometer (1) and the second optical fiber adapter (9); the collimating lens (4), the sample platform (7) and the coupling lens (8) are arranged between the first optical fiber adapter (3) and the second optical fiber adapter (9); the third optical fiber patch cord (13) is connected to the laser device (15) and the Raman probe (10); the fourth optical fiber patch cord (14) is connected to the grating spectrometer (16) and the Raman probe (10); and the Raman probe (10) and the first optical fiber adapter (3) are located at different heights. A near-infrared spectrum and a Raman spectrum of a sample can be synchronously measured, thereby realizing rapid measurement and analysis of the sample.

The application discloses a self-supporting thin film photocathode design method for improving the dynamic range of a transmission grating spectrometer, and the photocathode is designed by using a self-supporting thin film and an equal-width photocathode slit, so that the difference in photoelectron density in the high-energy area and the low-energy area of a diffraction spectrum is reduced, the dynamic range of the time-resolved transmission grating spectrometer is improved, and the time resolution of the spectrometer along the length direction of the photocathode is kept unchanged. Compared with a conventional equal-width photocathode and a flat-response photocathode, the self-supporting thin film photocathode can reduce the difference in photoelectron density in the high-energy area and the low-energy area of the diffraction spectrum on the photocathode, and improve the dynamic range of the spectrometer. Compared with a width-second-gradual photocathode, the self-supporting thin film photocathode can keep the time resolution of the time-resolved transmission grating spectrometer along the length direction of the photocathode unchanged, and solve the problem that the quantitative spectral analysis is difficult due to the change of the time resolution of the width-second-gradual photocathode along the length direction of the photocathode.

The invention relates to the technical field of spectral measurement, in particular to a compact broadband grating spectrometer and a spectral measurement method thereof.The compact broadband grating spectrometer comprises a vacuum chamber, a broadband light source, a slit assembly, a multi-grating control tower assembly and a detector assembly, and the multi-grating control tower assembly is arranged in the vacuum chamber; comprising a plurality of concave-surface variable-pitch diffraction gratings which are arranged on a grating turret mechanism and have different center line densities, the concave-surface variable-pitch diffraction gratings are switched between a working position and a non-working position along with rotation of the grating turret mechanism, and a grating mirror receives light beams from an incident window, disperses the light beams and reflects the light beams to an emergent window; and the detector assembly receives the dispersed spectral signal and realizes focusing detection. The multi-grating configuration capable of being rotatably switched is utilized, the wave band coverage range is effectively expanded on the premise that a complex mechanical structure is not introduced, the concave-surface variable-pitch gratings have the dispersion and focusing functions, the light path structure is simplified, aberration is reduced, and miniaturization and high resolution of the system are achieved.

The invention provides an automatic wavelength calibration method and device for a grating spectrometer, and belongs to the field of spectral analysis, and the method comprises the steps: collecting a spectrum of a selected atomic spectral line lamp, and obtaining a measurement spectrum containing a plurality of peak positions; all peak positions of the measurement spectrum are detected, a plurality of standard peak wavelengths in the standard spectrum of the atomic spectral line lamp are selected at the same time, then the measurement peak combination and the standard peak combination are subjected to proportion matching, and the measurement peak combination with the optimal proportion is screened out; carrying out expansion matching on the residual peak position of the measurement spectrum; and performing polynomial fitting on peaks of all matched spectral data, and calculating central wavelengths of all pixels to complete spectral calibration. The calibration efficiency is remarkably improved, the batch processing requirement is met, the equipment cost and the volume limitation are reduced, and the applicability is improved.

The invention relates to a grating spectrometer, in particular to a calibration device and a calibration method of the grating spectrometer. The calibration device comprises a composite adjustable light source used for providing one or more of an indication light source, a continuous light source or a standard wavelength light source; the dimming device is respectively connected with the composite adjustable light source and the slit of the spectrograph through optical fibers; the first light source target is movably arranged on the surface of a first reflecting mirror of the spectrograph and is used for calibrating the first reflecting mirror; the second light source target is movably arranged on the surface of the diffraction grating of the spectrograph and is used for calibrating the diffraction grating; the third light source target is movably arranged on the surface of a second reflecting mirror of the spectrograph and is used for calibrating the second reflecting mirror; and the fourth light source target is movably arranged on the surface of the CCD of the spectrograph and is used for calibrating the CCD. The calibration device of the grating spectrometer can adapt to grating spectrometers with different optical designs through the composite adjustable light source and the dimming device, the problem of insufficient universality is solved, and the production efficiency is improved.

The invention belongs to the field of plasma physics and spectroscopy diagnosis, and relates to a multi-grating space notch filtering spectrometer which comprises a slit, a semi-reflecting and semi-transmitting mirror, a lens, gratings, a notch reflector, a displacement platform, a total reflector and a detector. The gap width is adjusted through the displacement platform, continuous adjustment of the notch filtering range can be achieved, a user can freely select to filter out a single wavelength or a section of spectrum, and the device is suitable for different application scenes. The gap position accurately corresponds to the spectral space distribution after light splitting, and the filtering pertinence is very strong. Compared with a three-grating spectrometer, only two three-gratings are needed, the gratings are high-cost elements, the manufacturing cost is lower, meanwhile, the beam combining precision can be kept, and the three-grating spectrometer is compact in structure, small in size and easy to build. According to the multi-grating space notch filtering spectrometer, interference signals are accurately filtered out, the detector only receives effective spectrums, the signal-to-noise ratio is remarkably increased, and the multi-grating space notch filtering spectrometer is very beneficial to the field of weak signal detection.

The invention discloses a high-flux laser Thomson scattering multi-grating spectrometer which comprises an entrance slit, a first off-axis parabolic mirror, a first diffraction grating, a second off-axis parabolic mirror, an optical baffle, a third off-axis parabolic mirror, a second diffraction grating, a fourth off-axis parabolic mirror and a middle slit. A fifth off-axis parabolic mirror, a third diffraction grating, a sixth off-axis parabolic mirror and a detector; the off-axis parabolic mirror adopts a short-focus large-aperture design, and is used for collecting laser Thomson scattering photons in a high-flux manner, collimating and focusing laser Thomson scattering light beams without chromatic aberration and spherical aberration and deflecting a folded light path, and the structure realizes collimation and focusing of the Thomson scattering light beams without chromatic aberration and spherical aberration. The imaging quality of the multi-grating spectrometer is improved, spectrum distortion caused by aberration is avoided, the spectral resolution is improved, meanwhile, the luminous flux of the spectrometer is enhanced, and miniaturization and portable development of the spectrometer is achieved.

The invention relates to the field of spectral analysis, and provides a grating spectrometer and a method, the spectrometer comprises a shell and a grating, the grating is arranged in the shell; the temperature measuring unit comprises a light source, an FBG (Fiber Bragg Grating) and a demodulator, an optical fiber is connected with the light source and the FBG, the FBG is arranged at the back of the grating, and the demodulator outputs a reflection wavelength offset delta lambda B; the heater and the refrigerator are arranged in the shell; the calculation unit obtains a regulation and control temperature difference delta T according to the wavelength offset delta lambda B, and obtains regulation and control power P according to the temperature difference delta T; and the controller is used for controlling the heater or the refrigerator according to the regulation power P. The method has the advantages of high temperature control precision and the like.

The invention relates to grating light splitting, and particularly provides a grating spectrometer and method based on optical filter switching, and the grating spectrometer comprises a slit, a grating and a linear array detector. The driving unit is used for arranging the plurality of optical filters on an upstream optical path of the grating in a time division manner, band-pass wavebands of the optical filters are different, the band-pass wavebands comprise a broadband and a narrowband, the plurality of narrowbands are combined into the broadband, and part of the narrowband delta lambda0 cannot be directly received by the detector after being split by the grating; the reflection unit is used for reflecting split light of the narrow wave band delta lambda 0 to the detector, and the detector outputs light intensity I corresponding to the wide wave band, light intensity I2 corresponding to the narrow wave band delta lambda 0 and light intensity I1 of other narrow wave bands directly received by the detector; and the processing unit completes reconstruction of the light intensities I2 and I1 according to the light intensities I, I2 and I1. The method has the advantages of high resolution and the like.

This application discloses an optical sensing system based on dual Fabry-Perot cavities, comprising: a laser module, a main optical path module, and a reference optical path module. The laser module generates two laser beams, which enter the main optical path and the reference optical path respectively. The reference optical path module provides a reference signal for light source fluctuations to compensate for noise. The main optical path module includes: a dual Fabry-Perot cavity sensing unit, a total reflection mirror, a focusing lens, a grating spectrometer, an optical detector, and a signal processing unit. The dual Fabry-Perot cavity sensing unit in the main optical path module employs a novel micro-hemispherical dual-cavity interference structure, combined with a synchronous calculation method to test temperature and pressure changes. The technical solution provided in this application can achieve synchronous high-precision measurement of temperature and pressure by optimizing the cavity structure design, deepening the coupling effect between the gas medium and physical quantities, introducing high-precision decoupling algorithms and noise suppression mechanisms, thus meeting the application requirements of complex and harsh scenarios.

The invention belongs to the technical field of optical metrology testing, and particularly relates to a dispersion polarization spectral imaging system and method based on a Savart polariscope channel. The system comprises a demodulation module, and a front lens group, a polarization modulation module and a grating spectrometer which are sequentially arranged along the direction of an optical axis, the front lens group receives parallel light reflected by a target and enables the parallel light to enter the polarization modulation module, the polarization modulation module separates the parallel light to obtain interferograms with different wavelengths, and the grating spectrometer is used for receiving the interferograms. And the grating spectrometer performs dispersion on the interferograms with different wavelengths, and the demodulation module demodulates the interferograms with different wavelengths at different positions to obtain a polarization image of the target. According to the invention, target multispectral polarization information detection can be realized, the target multispectral polarization information can be obtained, and the detection efficiency is greatly improved.

The invention belongs to the field of laser Thomson scattering and other spectroscopy diagnosis, and discloses a filtering spectrometer using a single-grating folded optical path, which comprises a slit, a lens, a grating, a filtering reflector, a displacement platform, a total reflection mirror and a detector, by adjusting the width and the position of the gap in the middle of the notch reflector, continuous adjustment of the notch filtering range and the filtering center wavelength can be achieved, and the defect that the filtering effect of stray light signals in the center of a single-grating spectrometer is poor is overcome; the method has the characteristic of strong pertinence of filtering wavelength, not only can be used for filtering notch analysis of Thomson scattering signals, but also can be used for Raman scattering, fluorescence spectrum and other spectroscopy analysis needing filtering; compared with a three-grating spectrometer, only one grating and two lenses are needed, the grating belongs to a high-cost element, and the volume and the cost are greatly reduced while the three-grating filtering performance is maintained.

The invention relates to the technical field of optical instrument design, and discloses a line-distance-variable grating spectrometer performance and tolerance collaborative optimization method, a spectrometer, a system, a terminal and a medium, and the method comprises the steps: constructing a performance evaluation function of the spectrometer; determining an optimization variable, and obtaining a target optimization result meeting requirements according to the performance evaluation function and the optimization variable; performing tolerance analysis according to the target optimization result to obtain an evaluation result; and determining a design result of the spectrometer according to the evaluation result. According to the method, a strict ray tracing method is adopted to replace an approximation formula, the calculation precision is improved, high performance is pursued, and meanwhile it is ensured that the design scheme has the high yield under existing machining and assembling tolerances.

The application discloses a kind of width quadratic gradient light cathode design methods applied to stripe transmission grating spectrometer, comprising the following steps: step S1: with the center of light cathode base as origin (0,0) establishes rectangular coordinate system, light cathode slit length direction is defined as x-axis direction, and light cathode slit width direction is defined as y-axis direction;Step S2: light cathode slit edge coordinates comply with quadratic function and, step S3: establish zero-level center x-axis coordinate of silk.This application has the beneficial effects that: by using width quadratic gradient light cathode design, the signal intensity distribution of X-ray streak camera light cathode can be controlled, the signal intensity difference between high-energy region and low-energy region in transmission grating dispersion spectrum is reduced, and the problem of high dynamic range requirement for X-ray streak camera is solved.

The invention discloses a plane grating spectrometer system based on a lens array and pinhole filtering, belongs to the technical field of optical instruments, and aims to solve the problems of complex optical machine design, high coating requirement and high installation and adjustment difficulty in the prior art. In the invention, incident polychromatic light is introduced through an SMA905 optical fiber interface and becomes parallel polychromatic light after passing through an off-axis parabolic mirror, and light with different wavelengths in the parallel polychromatic light is focused at different positions after being converged by a lens array focusing system; light focused at different positions is subjected to spatial filtering through a small hole array filtering system formed by small holes located at different positions, polychromatic light emitted by the small hole array filtering system is collimated by a lens array collimation system, and collimated parallel light enters the surface of a digital micromirror device for channel gating; the light of the selected channel is reflected by the digital micromirror device, then is incident on the plane reflection grating for diffraction light splitting, and then is converged on the linear array detector after passing through the focusing mirror.

The utility model relates to a spectral analysis technology, and particularly discloses a wavelength-calibratable rotating grating spectrometer which comprises a wavelength screening element, a first collimating element, a rotating grating, a focusing element and a detector which are sequentially arranged along a light path of incident light, and further comprises a standard light source and a second collimating element, the standard light source is arranged between the wavelength screening element and the detector along the light path of the incident light, the light emitting side of the standard light source faces the rotating grating, and the second collimating element is arranged on the light emitting side of the standard light source. The rotating grating spectrometer capable of calibrating the wavelength can realize real-time wavelength calibration.

The present application relates to a kind of chessboard grating spectrometer vortex light beam four-step phase shift interference microscopic imaging system and method, belong to optical imaging field, including laser light source, beam expander, collimating mirror A, beam splitter A, chessboard grating A, collimating mirror B, vortex wave plate group, beam splitter B, beam splitter C, sample to be measured, microscopic objective A, small hole, microscopic objective B, chessboard grating B, mirror B, beam splitter D, camera and computer terminal;The present application uses chessboard grating spectrometer and vortex light phase shift interference in optical microscopic imaging, avoids the use of polarization camera, and can complete single collection interference pattern imaging, and measurement speed is fast, imaging precision is high, real-time is good, principle is simple, etc., provides a novel effective idea for optical microscopic imaging.

The invention provides a micro grating spectrometer. The micro grating spectrometer comprises a shell; the dispersion element and the sensor assembly are arranged on the shell, incident light is dispersed into monochromatic light by the dispersion element along an incident light path and then is reflected to the surface of the sensor assembly at different angles, and spectral information of the incident light is acquired by the sensor assembly; a spectrum dark area is further arranged, and the spectrum dark area is located on a propagation path of the incident light along the incident light path and used for increasing reflection loss of a specific wave band and absorbing energy of a high-sensitivity spectrum band so as to reduce sensitivity differences of all the spectrum bands.

The present invention relates to a method for spectral calibration and correction of an on-orbit grating spectrometer, comprising the following steps: Step 1: Accurate measurement of reference light source characteristics and initial light field modeling; Step 2: In-depth simulation of the light scattering process in a diffuse transmission plate; Step 3: Comprehensive calculation of the process of light transmission to the entrance pupil of the spectrometer; Step 4: Development and implementation of a spectral offset correction strategy. The method for spectral calibration and correction of an on-orbit grating spectrometer of the present invention can complete high-precision spectral tasks and further improve the calibration accuracy. By utilizing the conditions of mercury lamps with different inclinations incident on the diffuse transmission plate of the spectrometer, and performing theoretical analysis and spectral calibration correction, such analysis can complete high-precision spectral calibration. The method for spectral calibration and correction of an on-orbit grating spectrometer of the present invention can improve the precision and accuracy of spectral measurement through precise calculation and analysis, and provide solid technical support for the application of spectral technology in many fields.

The application provides an exhaled gas synchronous detection device and method based on a superimposed spectrum model, and relates to the technical field of exhaled gas detection. The device comprises an LED broadband light source, a band-pass filter, a collimating lens combination, an optical resonant cavity, a converging lens, an optical fiber, a grating spectrometer, a detector and an upper computer. Infrared light emitted by the LED broadband light source passes through the band-pass filter, the collimating lens combination, the optical resonant cavity, the converging lens, the optical fiber and the grating spectrometer in sequence to form a composite light signal. The detector converts the composite light signal into a superimposed spectrum signal. The upper computer is integrated with an exhaled gas synchronous detection method based on the superimposed spectrum model, that is, the superimposed spectrum model is used for decoupling analysis of the superimposed spectrum signal. The technical scheme of the application overcomes the problems in the prior art, such as the superimposed interference of adjacent spectrum lines and high detection cost when synchronously detecting ethanol and n-pentane.

A real-time measurement method and apparatus for long-wave infrared pulse spectra based on nonlinear frequency upconversion is disclosed. The method utilizes a non-oxide semiconductor crystal as the nonlinear medium and employs a narrowband pulse with a center wavelength in the range of 2-2.5 μm as the sampling light. This pulse is summed with the long-wave infrared pulse to be measured, and the resulting summed pulse is received and detected by a near-infrared real-time spectrometer. The combination of the selected sampling light wavelength and the selected crystal generates an ultra-wide phase-matching bandwidth. Through a linear frequency mapping relationship, the spectrum of the long-wave infrared pulse to be measured can be inverted from the detected summed pulse spectrum. By analyzing the spectrum acquired by the near-infrared spectrometer in real time, the spectrum of the long-wave infrared pulse to be measured can be directly and in real-time reconstructed. This invention overcomes the limitations of Fourier transform spectrometers and traditional grating spectrometers in real-time measurement, achieving real-time, mechanical-scan-free measurement of long-wave infrared pulse spectra without requiring a specific repetition frequency for the long-wave infrared pulse.