117 results about "Michelson interferometer" patented technology

The invention discloses a non-equilibrium Michelson interferometer electric field sensor capable of automatically calibrating temperature influence, which has the characteristics of wide bandwidth, high measurement precision and small interference of distribution of an electric field to be measured, and can also automatically calibrate temperature influence and prevent a working point of the non-equilibrium Michelson interferometer electric field sensor from deviating. The electric field sensor comprises a lithium niobate substrate, the lithium niobate substrate is provided with a non-equilibrium Michelson interferometer, the non-equilibrium Michelson interferometer comprises an input and output waveguide, the input and output waveguide is connected with a first waveguide arm and a second waveguide arm which are different in length, two sides of the first waveguide arm are provided with electrodes, and the second waveguide arm is provided with electrodes. An antenna is arranged on the electrode, a first metal reflecting mirror is arranged at the tail end of the first waveguide arm, a second metal reflecting mirror is arranged at the tail end of the second waveguide arm, the first metal reflecting mirror and the second metal reflecting mirror are both arranged on the lithium niobate substrate, and the thermal expansion coefficients of the first metal reflecting mirror and the second metal reflecting mirror are different.

The invention provides a dynamic interference focusing method and system based on a Michelson interferometer, and the method comprises the steps: obtaining interference fringes under different defocusing amounts through employing the dynamic interference focusing system based on the Michelson interferometer, carrying out the analysis of the received interference fringes through an upper computer, and obtaining phase information, based on the phase information of the interference fringes corresponding to different defocusing amounts, a mapping relation between the defocusing amounts and the phase information is constructed; in the application, the current interference fringes are obtained through the dynamic interference focus fixing system of the Michelson interferometer, the current interference fringes are analyzed through the upper computer to obtain the current phase information, and the current defocusing amount is obtained by adopting the mapping relation based on the current phase information. And moving the sample to a calibrated focal plane position by controlling a dynamic interference focus fixing system of a Michelson interferometer based on the current defocusing amount to complete automatic focus fixing. The method can achieve the nanoscale focusing sensitivity.

The invention provides a time delay interference ground semi-physical experiment verification scheme, which comprises the following steps of: (1) based on a space gravitational wave detection task and a load configuration scheme, acquiring core measurement of the space gravitational wave detection task, and recording measurement data; (2) constructing an algebraic relationship of a time delay interference scheme for effectively eliminating secondary noise such as laser frequency noise and optical platform jitter, and calculating according to the algebraic relationship to obtain a solution of first-generation time delay interference and a solution of first-generation basic combination; and (3) repeating the step (2) for multiple rounds to compensate the difference of the equivalent interference measurement arm length and further suppress the laser frequency noise. The half-physical simulation platform is reasonable in conception, the half-physical simulation platform of the Michelson interferometer with the unequal arms and equivalent to the million kilometer arm length is built by combining an arm locking frequency stabilization system and an electronic phase time delay system, and effective suppression of laser frequency noise is achieved.

The invention provides a silicon-based free space type optical MEMS accelerometer and a manufacturing method, the upper layer of the accelerometer is a glass substrate free space optical sensitive structure, the lower layer of the accelerometer is a silicon-based horizontal axis MEMS sensitive structure, and the upper layer structure is fixed on the lower layer structure through a bonding process. Wherein the upper-layer optical sensitive structure consists of a pair of Michelson interferometers, a glass anchor point and a glass mass block; and the lower-layer MEMS sensitive structure consists of four groups of cantilever beams, a silicon anchor point and a silicon mass block. The lower layer MEMS sensitive structure converts the horizontal shaft input acceleration into the displacement of the silicon mass block, the displacement is synchronously transmitted to the glass mass block, and the pair of oppositely arranged Michelson interferometers converts the displacement into the reverse transformation of an interference light phase, so that the high-precision differential detection of the acceleration is realized. The micro-optical accelerometer scheme provided by the invention has the outstanding advantages of high detection sensitivity, strong common-mode error resistance and high integration level.

The invention relates to the technical field of ultrafast laser and light quantum, and provides a single-cavity double-optical-comb absolute distance measurement system and method based on repetition frequency scanning. The system comprises a single-cavity double-optical comb system which is used for simultaneously establishing clockwise and anticlockwise propagating mode-locked pulses in an annular cavity through a bidirectional pumping source and outputting a main oscillation optical comb and a local oscillation optical comb through a polarization maintaining optical fiber coupler; a first piezoelectric ceramic and a second piezoelectric ceramic are arranged in the annular cavity, and the first piezoelectric ceramic and the second piezoelectric ceramic are adjusted through a differential driving mode so as to lock and regulate the repetition frequency difference between the main oscillation optical comb and the local oscillation optical comb; the double-optical-comb distance measuring system is used for combining the main oscillation optical comb passing through the Michelson interferometer with the local oscillation optical comb not passing through the Michelson interferometer to generate a radio frequency beat frequency signal; and calculating the real-time absolute distance of the measured target according to the optical path difference of the radio frequency beat frequency signal and the repetition frequency difference of the main oscillation optical comb and the local oscillation optical comb.

The invention provides an ultrafast scanning interferometer. The interferometer comprises an ultrafast laser system, an interference module, a coupling module and a spectral measurement module which are sequentially arranged along a light path. The ultrafast laser system emits a laser beam, the interference module splits the laser beam into a reference beam and a detection beam, and the detection beam carries information of a detected optical element. The coupling module is connected with the spectral measurement module through an optical fiber, the coupling module couples the detection light beam into the optical fiber, and the spectral measurement module demodulates the detection light beam which is output by the optical fiber and carries the information of the detected optical element in real time and calculates the peak-valley value of the detected optical element. The interference module adopts a Michelson interferometer structure, and the spectral measurement module comprises a dispersion module, a high-speed photoelectric detector and a high-speed photoelectric signal acquisition and analysis module. According to the invention, continuous single-frame detection is carried out on the measured optical element in the form of the optical pulse string, and high-precision and high-efficiency measurement of the surface topography of the optical element is realized.

The invention discloses a dual-wavelength polarization tuning interference spectrum frequency discrimination device and a synchronous frequency locking method, and the method specifically comprises the steps: enabling a polarization Michelson interferometer to divide incident laser into two beams of linearly polarized light through a plurality of achromatic wave plates and a polarization splitting prism, and enabling the two beams of linearly polarized light to form dual-wavelength circularly polarized light for output after the two beams of linearly polarized light are reflected and combined; the output light is divided into two beams after passing through a light splitting module, and the two beams are respectively collected and processed into a four-quadrant synchronous phase-shifting interferogram by a polarization camera after passing through an achromatic lens, and the wavefront phase difference is calculated in real time; the other beam is compensated by the rotary linear polarizer and then is received by the detector; through the corresponding relation between the wavefront phase difference and the rotation angle, the rotation linear polarizer is driven in real time to carry out phase compensation, so that polarization tuning and frequency locking are realized; meanwhile, a piezoelectric mirror bracket control signal is obtained through calculation, and interferometer parallelism error correction is carried out. According to the invention, synchronous real-time monitoring and active feedback locking of dual-wavelength interference signals can be realized, and the system has the advantages of high tuning resolution and accurate data.

The invention provides a high-precision ghost diffraction encryption method for a dynamic target, and the method comprises the steps: carrying out the observation of the moving number of interference fringes of an object through a Michelson interferometer, carrying out the phase calculation, obtaining a set of observed phase change values, carrying out the conversion of the set of observed phase change values through a conversion function, and carrying out the encryption of the ghost diffraction. And taking the conversion function as a first-level key, establishing a ghost diffraction light path based on the optical element and the first-level ciphertext, and performing ghost diffraction operation on the first-level ciphertext and the four reference quantities respectively to obtain a second-level ciphertext and a second-level key respectively. According to the method, the ghost diffraction technology is introduced into the encryption process, ghost diffraction performs imaging by using the statistical correlation characteristic of the light field, and the image can still be restored through the statistical correlation characteristic under the condition that part of the light path is shielded or is interfered by noise, so that the anti-interference performance of the encryption method provided by the invention is effectively enhanced.

The application provides a grinding liquid film thickness measuring device and a measuring method thereof and relates to the technical field of semiconductor processing processes. The light emitted by the light source forms first light and second light through the setting of the measuring assembly. Since the grinding liquid serves as a medium between the second light, the thickness of the grinding liquid can be obtained in real time by measuring the optical path difference change between the first light and the second light through the principle of the Michelson interferometer.

The invention discloses a precise measurement method for object surface out-of-plane displacement under high-frequency micro-vibration. The method comprises the following steps: exciting an object to generate high-frequency steady-state vibration through a vibration exciter, freezing a surface state at any vibration position of the object by adopting stroboscopic pulse laser with strictly same frequency as the vibration, and forming a shear speckle field by utilizing a Michelson interferometer comprising a piezoelectric ceramic driving phase-shifting mirror. The movement of the phase shift mirror and the acquisition of the high-speed camera as well as the actions of the stroboscopic laser and the vibration exciter are synchronously controlled through the double-signal controller, so that the accurate acquisition of multiple phase shift speckle interference images is realized. The image is processed based on a four-step phase shift algorithm, and the phase difference of the vibration position is calculated, so that the out-of-plane displacement derivative and the out-of-plane displacement in the shearing direction are calculated. According to the invention, the signal-to-noise ratio and the sensitivity of vibration measurement are obviously improved, and the method has full-field, non-contact and micro-nano displacement resolution capabilities, and is suitable for the fields of material nondestructive testing and structure health monitoring.

The invention relates to the field of optical fibers, in particular to a D-type optical fiber based on Fe3GaTe2 nanosheets and a preparation method and application of the D-type optical fiber. The invention discloses a D-type optical fiber based on a Fe3GaTe2 nanosheet. The D-type optical fiber comprises a D-type optical fiber and a Fe3GaTe2 layer deposited on a D-type plane of the D-type optical fiber. By utilizing the evanescent field characteristic of the D-type optical fiber, the Fe3GaTe2 nanosheet is deposited on the D-type plane of the D-type optical fiber, and magnetic anisotropy change (such as magnetization direction switching) is generated under the action of an external magnetic field, so that the effective refractive index of the optical fiber is changed; the change is converted into an optical path difference in the Michelson interferometer. Finally, the magnetic field intensity can be inverted by measuring the FSR change of the interference spectrum. The room-temperature MA adjustability of the Fe3GaTe2 nanosheets provides a larger refractive index change range (superior to that of magnetic fluid), and the nanosheets are not easy to degrade, so that the D-type optical fiber has higher sensitivity and temperature performance.

The present disclosure belongs to the field of photoacoustic signal detection, and specifically relates to a quantum-enhanced all-optical photoacoustic signal detection device and method. The problem of low sensitivity of photoacoustic signals based on interference measurement is solved, and high-sensitivity detection of photoacoustic signals generated by living organisms including human bodies can be achieved. A degenerate optical parametric oscillator based on a first-type phase matching crystals is used for preparing a vacuum squeezed state light field, a coherent control technology is used for locking the squeezed angle to obtain the quadrature phase vacuum squeezed state, the prepared quadrature phase vacuum squeezed state light field is injected into the vacuum channel of a Michelson interferometer, and a balanced homodyne detection mode is used for achieving detection of the quantum-enhanced photoacoustic signals.

A push-pull type optical fiber MEMS accelerometer based on Michelson interferometer comprises a mechanical assembly and two sensing optical fibers, the mechanical assembly is composed of a fixed base and an acceleration sensing chip, the acceleration sensing chip comprises an outer frame, a mass block and two groups of spring cantilever beams, the outer frame is provided with a fine optical fiber slot, the mass block is provided with two convex structures as reflecting surfaces, the sensing optical fiber end face and the top surface of the mass block convex structure form two air cavities as sensing arms of the Michelson interferometer. When the accelerometer is subjected to external acceleration, the mass block moves relative to the outer frame, the cavity length of the two air cavities changes in a push-pull manner, thereby changing the optical path and generating an interference signal. The interference signal is collected and demodulated by a photoelectric detector, a data acquisition circuit and a computer, and a vibration acceleration signal can be obtained. The present application has the advantages of high sensitivity, strong noise common mode rejection capability and is suitable for various dynamic vibration response measurement occasions.

The invention belongs to the field of distance measurement, and particularly discloses a pen type optical fiber spectrum interference distance measuring probe and a measuring system. The probe comprises an adjusting unit and a measuring unit, the adjusting unit comprises a bottom shell, a measuring shell, a limiting shell and an elastic piece, the bottom shell is connected with the limiting shell, the measuring shell is arranged between the bottom shell and the limiting shell in an axially movable mode, the bottom shell and the measuring shell are each provided with a distance positioning part, and the elastic piece is used for providing elastic force enabling the measuring shell to be separated from the bottom shell; the measuring unit comprises an optical fiber spectrum interference module and a reflection module, one of the optical fiber spectrum interference module and the reflection module is arranged in the measuring shell, the other of the optical fiber spectrum interference module and the reflection module is arranged in the bottom shell, and the optical fiber spectrum interference module and the reflection module form a Michelson interferometer; the probe has the advantages of being high in measurement precision and reliability, small in size, large in measurement range and easy and convenient to operate, is suitable for precise measurement of various gaps, and is particularly suitable for precise interval measurement of the gaps in a narrow space.

The application provides a time delay interferometric ground semi-physical experimental verification scheme, which comprises the following steps: (1) based on a space gravitational wave detection task and a load configuration scheme, acquiring a space gravitational wave detection task core measurement, and recording measurement data; (2) constructing an algebraic relationship of a time delay interferometric scheme capable of effectively eliminating laser frequency noise and secondary noise such as optical platform jitter, and calculating a first generation time delay interference and a first generation basic combination solution according to the algebraic relationship; (3) repeating the above step (2) for multiple rounds, compensating for the difference of the equivalent interference measurement arm length, and further suppressing laser frequency noise. The application has reasonable concept, and a semi-physical simulation platform of an equivalent million kilometer arm length unequal arm Michelson interferometer is built by combining a lock arm frequency stabilization system and an electronic phase delay system, so that effective suppression of laser frequency noise is realized.

An ultraprecision frequency-domain Light Detection and Ranging (LiDAR) system for remote micro-movement sensing includes a laser diode with a bandpass filter configured to modulate power using RF signals to generate intensity-modulated optical signals. The LiDAR system includes a Michelson interferometer to split generated optical signals via a 50 / 50 directional coupler into two optical paths. A first optical path includes a fiber-optic delay line with a silver-coated end reflecting phase-shifted optical signals towards a photodetector. A second optical path features a semiconductor optical amplifier amplifying the generated optical signals, with an optical collimator and a target beyond a free-space propagation region. A photodetector is connected to the 50 / 50 directional coupler that receives both the phase-shifted and amplified optical signals, converting them to electrical signals. A feedback loop, including a bandpass filter and a frequency-domain analyzer detects frequency shifts caused by micro-movements of the target.

A distributed fiber optic sensing system for measuring temperature and strain based on OCDR-SOCF (Optical Detection and Conversion) technology includes a laser, an isolator, a collimator, a polarization controller, a coupler, an acousto-optic modulator (AOM), a polarization diversity photodetector (PDD), and a signal acquisition and processing module. The laser light generated by the laser passes through the isolator and enters a Michelson interferometer. One path of the laser light is calibrated by the collimator and injected into the optical fiber. The returned Rayleigh backscattered light passes through the polarization controller and is then injected into the coupler. The other path of the laser light passes through the acousto-optic modulator and is then injected into the coupler. The two signals enter the polarization diversity photodetector, where they interfere and generate a current signal, which is then output to the signal acquisition and processing module. The signal acquisition and processing module synthesizes the coherence function to achieve simultaneous fiber temperature and strain sensing. This system facilitates measurement, reduces system complexity, and reduces system cost.

The application discloses a moving mirror system of a Michelson interferometer based on magnetic suspension positioning technology, which comprises a moving mirror main body and three electromagnet groups. The moving mirror main body comprises a lens base, a metal mirror, connecting rods and magnetic pole balls. The number of the connecting rods is three, and the three connecting rods are arranged on the side edges of the lens base. The number of the magnetic pole balls is three, and the three magnetic pole balls are arranged on the other ends of the three connecting rods respectively. The electromagnet group comprises an electromagnet support, coils and magnetic pole heads. The electromagnet support is composed of three wedge-shaped bodies. The number of the coils is three, and the three coils are fixed on the three wedge-shaped bodies by electromagnet bolts respectively. The application has the advantages of no abrasion, simple realization, easy control and easy manufacturing. Meanwhile, the precision is not lost due to the increase of the use frequency and use time. Since only electromagnets are adopted as the core parts, the machining and manufacturing are very simple and easy, and the technical threshold of production design and manufacturing is lowered.

The invention discloses a laser Michelson interferometer for observing and interfering three-dimensional space distribution of a light field by using a photoluminescence effect. The laser Michelson interferometer comprises a laser, a lens, a beam splitter prism, two reflectors and a photoluminescence medium, laser emitted by the laser device is shaped by the lens, then enters the beam splitter prism and is divided into a transmission light beam and a reflection light beam, and the transmission light beam and the reflection light beam are reflected by the two reflectors respectively, return along the same path, then are reflected / transmitted by the beam splitter prism and enter the photoluminescence medium to form an interference light field; and complete three-dimensional space light field distribution can be observed through fluorescence.

The invention provides a high-temperature and high-pressure sensor based on an optical fiber interferometer of a cascade structure of a Michelson interferometer (MI) and a Fabry-Perot interferometer (FPI) and a preparation method of the high-temperature and high-pressure sensor. According to the sensor, the conical single-mode fiber and the coreless fiber are welded to form an MI structure, the MI structure is sealed in the quartz capillary to form an FPI cascade structure, and due to the fact that the sensor adopts an arc discharge non-adhesive packaging technology, high temperature and high pressure can be measured at the same time. Wherein temperature sensing can be realized by monitoring MI characteristic spectrum change, and pressure measurement can be realized by monitoring FPI cavity length change caused by pressure. The sensor has the advantages of strong anti-interference capability, high stability and the like, and is suitable for temperature and pressure measurement under complicated working conditions of petrochemical engineering, aerospace and the like.

The application provides a silicon-based free-space optical MEMS accelerometer and a manufacturing method, the upper layer of the accelerometer is a glass substrate free-space optical sensitive structure, the lower layer is a silicon-based horizontal axis MEMS sensitive structure, and the upper layer structure is fixed on the lower layer structure through a bonding process. The upper layer optical sensitive structure is composed of a pair of Michelson interferometers, a glass anchor point and a glass mass; the lower layer MEMS sensitive structure is composed of four groups of cantilever beams, a silicon anchor point and a silicon mass. The lower layer MEMS sensitive structure converts the horizontal axis input acceleration into the displacement of the silicon mass, the displacement is synchronously transmitted to the glass mass, and a pair of reversely arranged Michelson interferometers convert the displacement into the reverse transformation of the phase of the interference light, so that the high-precision differential detection of the acceleration is realized. The micro-optical accelerometer scheme provided by the application has the outstanding advantages of high detection sensitivity, strong anti-common-mode error capability and high integration.

The invention discloses an infinitesimal displacement automatic measuring device and method based on a Michelson interferometer, and belongs to the technical field of infinitesimal displacement measurement. The system comprises an optical amplification and display system and a Michelson interference system, wherein the optical amplification and display system comprises a microscope, a high-definition camera and a display screen; wherein the high-definition camera is used for recording the moving process of an object to be measured; the display screen is used for displaying and playing pictures shot by the high-definition camera; indication marks are arranged on a movable mirror of the Michelson interference system and used for indicating the starting point and the ending point of an object to be detected on the display screen. According to the invention, through mutual cooperation of the optical amplification and display system and the Michelson interference system, a moving path of an object to be measured can be amplified firstly, then measurement is carried out, and compared with a traditional Michelson interferometer, the measurement precision is greatly improved. And meanwhile, a rigid linkage structure of the movable mirror and the indication mark is adopted, so that the purpose of inhibiting dynamic errors is achieved, and the accuracy of a measurement result is further improved.

A distance measuring device is provided with: a light source unit that emits a first laser beam and a reference laser beam; a reference interference system for detecting first interference light generated by interference of the first laser light and second interference light generated by interference of the reference laser light, and outputting a first signal; a measurement interference system to which first reflected light generated by reflecting the first laser light by the object is input, and which outputs a second signal; and a signal processing system that generates wavelength information relating to the wavelength of the first laser beam on the basis of the first signal, and calculates the distance from the distance measuring device to the object on the basis of the wavelength information and the second signal, the reference interference system being a Michelson interferometer.

The invention provides Fourier transform spectral imaging equipment and a spectral imaging method, and relates to the field of spectral imaging, the Fourier transform spectral imaging equipment comprises a Michelson interferometer, the Michelson interferometer comprises a scanning galvanometer fixedly arranged on a rotating shaft, and the Michelson interferometer is used for carrying out spectral imaging when the scanning galvanometer does reciprocating rotation motion along the rotating shaft; generating first interference light, and guiding the first interference light to the sample to be detected; the digital micromirror is used for displaying a plurality of modulation patterns and carrying out intensity modulation on second interference light by utilizing the plurality of modulation patterns to obtain a plurality of beams of third interference light, and the second interference light is obtained after the first interference light and the sample to be detected act; the photoelectric detector is used for receiving the plurality of beams of third interference light to obtain a plurality of modulation interferograms; and the control host is used for performing compressed sensing imaging based on the plurality of modulation patterns and the plurality of modulation interferograms to obtain a spectral image.

This invention provides a system for simultaneously measuring thin film thickness and refractive index based on spectral domain optical coherence tomography. It employs a free-space Michelson interferometer structure, using a beam splitter to separate broadband low-coherence light into reference and sample light. The two beams propagate separately in the free-space reference arm and free-space sample arm, respectively, before being combined and interfering. This fundamentally avoids the adverse effects of dispersion, polarization changes, and optical path drift introduced during fiber optic transmission. Simultaneously, this invention utilizes spectral domain optical coherence tomography to obtain the depth position information of different reflective interfaces in the sample arm. Combined with the positional changes of the plane mirror under reference and sample conditions, the geometric thickness and refractive index of the thin film can be simultaneously obtained by solving a simple set of equations. This simplifies the measurement process, improves data processing efficiency and measurement operability, and provides a reliable technical foundation for online monitoring and quality control in industrial coating processes.

The utility model relates to the technical field of physical optical experiments, and discloses a Michelson interference fringe automatic counter, which comprises a laser light source, a Michelson interferometer and a photosensitive diode, the Michelson interferometer is fixedly installed, the laser light source is arranged at the light source input end of the Michelson interferometer, and the Michelson interferometer is arranged at the light source input end of the Michelson interferometer. A diode fixing frame is arranged at the annular pattern output position of the Michelson interferometer, an observation screen is arranged on the diode fixing frame, the observation screen is located at the annular pattern imaging position of the Michelson interferometer, a photosensitive diode is arranged on the diode fixing frame, the light receiving surface of the photosensitive diode is located at the position of the observation screen, and the light receiving surface of the photosensitive diode is located at the position of the observation screen. And the photosensitive diode converts the ring pattern of the Michelson interferometer into an electric signal and outputs the electric signal. According to the utility model, the number of interference ring patterns can be automatically counted, and a fast, accurate and fast metering method is provided for optical experiments.

The invention relates to the technical field of engineering curvature measurement, and discloses a high curvature sensitivity Michelson interferometer structure and a preparation process, the high curvature sensitivity Michelson interferometer structure comprises a core sensing unit of a double non-adiabatic cone cascade solid sphere structure with a length of about 700 [mu] m, a single mode fiber with a core diameter of 8.2 [mu] m and a cladding of 125 [mu] m is tapered by a fusion splicer according to the parameters of tapering delay of 300 ms, a speed of 0.75 [mu] m / ms, a length of 350 [mu] m and the like, and a high curvature sensitivity Michelson interferometer is obtained. And discharging to form double cones, fusing and shrinking to prepare a solid ball, and calibrating the diameter of the waist of each cone to be 10-15 microns. The sensitivity of the interferometer within the curvature range of 0.18-0.8 m reaches-52.18 nm / m, the temperature crosstalk at 40-120 DEG C is 0.000282 m / DEG C, and the interferometer has the advantages of compactness, high sensitivity, low crosstalk and low cost and is suitable for health monitoring of high-precision structures in aerospace, precision industry and the like.

The invention discloses a device and a method for synchronously measuring the refractive index and the thickness of a transparent material, a Michelson interferometer is improved on the basis of the Michelson interference principle, and a reflecting mirror, an attenuation sheet with known refractive index and thickness and an optical screen are utilized after multiple light splitting designs. Three groups of interference fringes of different surfaces of the transparent material and the reflecting mirror are obtained, and the surface appearance and the refractive index of the transparent material are measured at the same time by combining the fringe radius.

The invention relates to a pulse measurement method based on two-photon absorption, and the method comprises the following steps: S1, selecting perovskite as a medium, and placing the medium on a sample stage of a Michelson interferometer; s2, the light source emits an ultrashort laser pulse to be measured and divides the ultrashort laser pulse into two paths of pulses, one path of pulse passes through the adjustable delay line and then is combined with the other path of pulse in perovskite, and a two-photon absorption signal is generated; and S3, obtaining a two-photon absorption interference autocorrelation curve IAC experiment through the two paths of pulses and the two-photon absorption signal, and reconstructing to obtain complete information of the to-be-measured ultrashort laser pulse by combining the spectral intensity of the to-be-measured ultrashort laser pulse. According to the invention, multi-photon absorption response is taken as a core detection mechanism, so that the technical limitation of traditional non-linear effects depending on second harmonic generation and the like is effectively broken through, the problem that materials such as perovskite and the like do not have second harmonic so that pulse measurement cannot be realized is solved, and measurement of higher sensitivity and wider wave band of ultrafast light pulses is realized.

The invention belongs to the technical field of acoustic measurement, and discloses a free space sound field measurement method and system, and the method comprises the steps: constructing a free light path sound field measurement system based on a Michelson interferometer principle; acquiring a reference image, introducing a sound field to be measured, and controlling a loudspeaker or a laser beam to perform translation and rotary scanning through a computer to complete interference pattern data acquisition; preprocessing the acquired interference pattern, identifying the edge of the interference fringes by using an edge detection technology, and carrying out light phase variation calculation; and performing sound field reconstruction by adopting a Radon inverse transformation algorithm, converting sound field integral information carried by a laser beam into a sound pressure value of each point in a real space, and reconstructing a free field sound pressure distribution diagram. The method has the advantages of no damage and low cost, the measurement precision of the sound field and the integrity and reliability of reconstruction are remarkably improved, the nano-scale optical path change caused by the sound field can be effectively captured, and the high precision of sound field measurement and the accuracy of sound source recognition are ensured.