105 results about "Lock-in amplifier" patented technology

The invention relates to the technical field of quantum sensing, and discloses a quantum magnetometer device based on diamond NV color center photoelectric detection magnetic resonance. Wherein the optical path module performs optical excitation and imaging positioning on a diamond sample through a laser and an objective lens. The circuit module integrates a microwave source, a lock-in amplifier, a low-noise current amplifier and a programmable power supply, applies a microwave field and bias voltage to a microwave antenna and an interdigital electrode on the surface of a sample respectively, and collects sample dependency photocurrent signals. And the operation module realizes automatic control and data processing of the system. According to the device, NV color center spin state information is converted into a photocurrent signal through a photoelectric detection magnetic resonance mechanism, an amplitude or frequency modulated signal is demodulated by using a lock-in amplification technology, information of a detection magnetic field is obtained through a high signal-to-noise ratio photoelectric detection magnetic resonance spectrum, and the sensitivity of the magnetic field is evaluated. Magnetic resonance signals are detected in an all-electricity mode, a complex optical system of traditional fluorescence detection is simplified, and the device has the advantages of being compact in structure, easy to integrate, high in measurement sensitivity and the like.

The invention discloses a device and a method for measuring the velocity field of an autoclave through hot-pressing wind speed. The device comprises a thermosensitive probe, a Wheatstone bridge, a lock-in amplifier, an NI multi-channel data acquisition card and a computer, the thermosensitive probe is used for instantaneously detecting the temperature of a placement point position and generating resistance fluctuation based on sensing temperature change; the Wheatstone bridge is formed by connecting a fixed resistor, a variable resistor and a thermosensitive probe, and is used for forming a series circuit with the lock-in amplifier; the lock-in amplifier is used for supplying power to the Wheatstone bridge and providing co-frequency voltage at the same time, so that resistance data of a thermosensitive probe in the Wheatstone bridge is converted into voltage data to be output; the NI multi-channel data acquisition card is used for acquiring in-phase component voltage signals output by the lock-in amplifier; the computer is used for processing the voltage data to obtain the average speed and the pulsation speed of the measurement point. According to the invention, the problems of limited precision, insufficient sensitivity and poor adaptability to the internal environment of the autoclave in the conventional gas speed measurement method are solved.

The invention relates to a high-precision temperature detection system based on an alternating-current impedance bridge. The high-precision temperature detection system comprises a double-resistance bridge circuit, a lock-in amplifier and a differential circuit, the double-resistor bridge circuit comprises a resistive temperature sensor and a standard resistor which are connected in series, and the phase-locked amplifier is a digital phase-locked amplifier realized based on an FPGA (Field Programmable Gate Array). Wherein the initial potential of a first voltage measurement end arranged at the midpoint of the double-resistor bridge circuit is zero by adjusting the two excitation signals which are loaded to the double-resistor bridge circuit and have the same frequency and opposite phases before temperature measurement; in the temperature measuring process, the lock-in amplifier detects the potential of the first voltage measuring end and the voltage at the two ends of the standard resistor through the differential circuit, then the resistance value of the resistance-type temperature sensor is calculated by combining the resistance value of the standard resistor, and then the temperature of the resistance-type temperature sensor is reduced. According to the invention, the anti-interference capability can be improved, and the measurement precision of 0.1 mK level can be reached near 273K.

The invention discloses a rheology-birefringence combined in-situ testing device and method based on chopper rotation frequency signals, belongs to the technical field of optical testing, and aims to solve the technical problems that an existing Spark-FB device is low in measurement accuracy and limits application scenes. The laser emitter emits a light beam along a set angle (forming an angle of 45 degrees with the horizontal plane), the light beam is converted into linearly polarized light through the polarizer, and an optical signal is modulated through the rotating chopper; the modulated light beam penetrates through a polymer sample to which a shear flow field is applied by a commercial rheometer, and transmission light carrying optical anisotropy information of the sample sequentially passes through a 1 / 4 wave plate and a polarization analyzer, and is finally received by a photoelectric detector and transmitted to a lock-in amplifier for analysis. According to the invention, an independent datum reference signal is provided through the chopper, decoupling and combination of a commercial rheometer and a birefringence light path are realized, and synchronous and accurate in-situ measurement of rheological and optical properties of a high polymer material under a deformation condition can be realized.

The invention relates to a Rydberg atomic communication receiving system and method based on AT split peak value analysis, and belongs to the technical field of quantum communication. The system comprises a detection laser, a coupling laser, an AOM / EOM, a function generator, a high-frequency signal generator, a cesium atom gas chamber, a photoelectric detector, a lock-in amplifier, a data acquisition module and a microwave signal output module. The AOM / EOM modulates the frequency of the detection laser; the microwave signal output module generates an AM modulation microwave signal and transmits the AM modulation microwave signal to the cesium atom gas chamber, so that the target Rydberg state atoms generate an AT splitting effect to calibrate system parameters; the photoelectric detector and the lock-in amplifier obtain a first harmonic component based on the transmission light. During communication, the system is arranged in a microwave electric field received by communication, and the data acquisition and processing module outputs AM modulation microwave signals received by the recovered cesium atom gas chamber based on calibrated system parameters and phase locking. The method solves the problem of signal distortion existing in EIT-AT direct communication transmission and the problem of tedious operation of a heterodyne method.

According to various embodiments, a sensing device for measuring oxygen concentration cycles in breath is disclosed. The sensing device includes a laser configured to emit light at an A-band of oxygen, a lens configured to collimate the light, and a multi-pass cell configured to contain a replaceable sample cell. The light passes through the multi-pass cell and is attenuated by oxygen in the sample cell. The sensing device further includes a photodetector configurated to convert the attenuated light into an electrical signal, and a lock-in amplifier or an equivalent processing circuit configured to determine oxygen concentration from the electrical signal.

The invention discloses a multi-mode nanometer measurement system and method based on terahertz scattering type scanning near-field optical microscopy and multi-frequency electrostatic force microscopy, and belongs to the technical field of near-field imaging, the measurement system comprises an AFM main body, a terahertz source, an optical path system, a terahertz detector, a multi-frequency signal generator and two phase-locked amplifiers; terahertz waves emitted by the terahertz source reach the terahertz detector through the optical path system, and near-field optical signals are obtained. The AFM comprises a metal coating probe; the multi-frequency signal generator generates sinusoidal signals with frequencies of omega1 and omega2; a sample is placed on the scanner, and the cantilever beam is controlled to vibrate at the frequency omega 1; an alternating voltage with the frequency of omega 2 is applied to a metal coating probe arranged at the top end of the cantilever beam; laser emitted by the laser is reflected to the light spot position detector through the cantilever beam, and morphology and electrostatic force signals are obtained through the two lock-in amplifiers respectively. According to the invention, a morphology signal, an optical signal and an electrostatic force signal can be synchronously obtained through single scanning.

A system for automatically locking a control laser in a Rydberg atomic sensor may comprise an atomic vapor cell, a probe laser configured to excite the atoms in the atomic vapor cell to an intermediate energy state, and a control laser configured to excite the one or more atoms in the atomic vapor cell from the intermediate energy state to a higher energy state. The light generated by the control laser may be dithered at a pre-determined frequency. The system further comprises a photodiode configured to convert light received from the vapor cell into an electrical signal, a lock-in amplifier configured to generate an error signal based on the electrical signal received from the photo diode and a received reference oscillation frequency, and a servo configured to receive the generated error signal from the lock-in amplifier and adjust a frequency of the control laser based on the received error signal.

The invention relates to the technical field of thermal interface material defect detection, in particular to a nondestructive detection method and system for thermal interface material application defects, and the system comprises an electric displacement table, heating laser, detection laser, a photoelectric detector, an acoustic optical modulator, a lock-in amplifier, an optical element and a data processing unit; the electric displacement table is used for fixing a sample and accurately controlling the position of the sample; the sample is of a silicon-thermal interface material-substrate sandwich structure; the upper-layer silicon wafer of the sample is plated with a metal film as a transduction layer; the heating laser is used for heating the sample; the acoustic optical modulator is used for modulating the heating laser, so that the heating laser heats the sample in a sine wave form; the detection laser is used for detecting sample temperature fluctuation; the photoelectric detector is used for collecting and detecting laser reflection signals; the lock-in amplifier is used for extracting and detecting laser phase and amplitude signals. According to the invention, non-destructive rapid detection of the defects of the thermal interface material in an application scene can be realized.

The invention relates to the technical field of quantum precision measurement and automatic control, and discloses a Rydberg atom AT split signal-based closed-loop locking detection method and a Rydberg atom AT split signal-based closed-loop locking detection system. The method comprises the following steps: acquiring an EIT signal under the condition of no microwave field, and locking the frequency of coupled laser at a preset reference point to establish a frequency reference; the coupled laser and the detection laser are combined and then collinearly penetrate through the gas chamber; when the to-be-measured microwave field is applied to the gas chamber to generate AT splitting, the laser frequency shifter controls the frequency of the coupled laser to be switched between preset target frequency points; a lock-in amplifier is used for carrying out phase-sensitive detection on a detection laser light path transmission intensity signal, an error voltage signal is generated based on an AT split signal, and error voltage zero crossing points corresponding to two AT split peaks are locked through a servo controller; and calculating the to-be-measured microwave electric field intensity according to the locking point feedback control quantity difference. According to the invention, the measurement precision is improved, the anti-interference capability is enhanced, the working stability is improved, and rapid and stable detection of the microwave electric field is realized.

The present invention relates to an optical modulation system based on the interaction of two collinear light beams having different wavelengths passing through a cuvette containing a solution of Cs2SnI6, comprising a pumping laser emitter emitting a modulated pumping beam with a wavelength between 355 nm and 1550 nm and with a variable frequency; a test laser emitter emitting a continuous wave test beam at 633 nm and with a power limited to 10 mW; a beam splitter where the pumping and test beams are combined to strike on the cuvette; a pass filter that removes the signal from the pumping beam; a spatial analysis camera; a time / frequency analysis equipment with a photodetector, a commercial lock-in amplifier and an oscilloscope; and a signal generator.

The utility model discloses a quartz enhanced photoacoustic spectrometry gas detection system based on coaxial main and auxiliary resonance tubes, which comprises a signal generator, an adder, a laser, a collimator, a gas sensing device, a preamplifier, a lock-in amplifier, a data acquisition system and a computer, a laser is arranged on one side of the summator, a collimator is arranged at the output end of the laser, a gas sensing device is arranged on one side of the collimator, a pre-amplifier is arranged on the rear side of the gas sensing device, and the output end of the pre-amplifier is connected with the input end of the phase-locked amplifier. The output end of the lock-in amplifier is connected with the data acquisition system, and the data acquisition system is connected with the computer. The ultra-low trace gas detection device is used for ultra-low trace gas detection, gas concentration detection is rapid, accurate and effective, and the minimum detection limit of gas can be obviously enhanced.

The application belongs to the technical field of photo-thermal spectrum gas detection, and particularly relates to a photo-thermal spectrum gas detection device and method based on a tapered optical fiber, which comprises an optical fiber gas chamber, a pump laser, a first wavelength division multiplexer, a second wavelength division multiplexer, a circulator, a probe laser, a photoelectric detector, a low-pass filter, a PID feedback control module, a power divider, a processor and a lock-in amplifier. Compared with the existing photo-thermal spectrum gas detection method and device based on a hollow optical fiber, the application can accelerate the gas sensing reaction speed, and on the other hand, due to the fact that the thermal-optic effect and the thermal expansion coefficient of the optical fiber material are significantly greater than those of the gas, the photo-thermal spectrum signal intensity of the tapered optical fiber will be significantly greater than that of the hollow optical fiber.

The application discloses a kind of gas chamber polarization enhancement magnetometer based on multifocal holographic super surface and measuring method, belong to magnetic field measurement technical field.The magnetometer includes laser generation and control module, 1 / 4 wave plate, multifocal holographic super surface, optical magnetic resonance module, optical pumping signal post-processing module and reflector.Laser is collimated after 1 / 4 wave plate and is incident to multifocal holographic super surface, the super surface carries out phase control to incident light, makes multiple focal planes in different depths in gas chamber, improves the spatial uniformity of light pumping, enhances alkali atom polarization rate.Transmitted light enters optical pumping signal post-processing module, passes through polarizing beam splitter prism polarizing beam splitter prism, balanced differential detector and lock-in amplifier, extracts magnetic resonance signal and calculates magnetic field intensity.The application optimizes light pumping process, improves the stability and signal-to-noise ratio of magnetic measurement system, reduces measurement error, and is suitable for geomagnetic detection, biological magnetic signal detection and other high-sensitivity magnetic field measurement fields.

Systems and methods of microscopy include and / or apply a laser light source configured to produce an excitation light; a modulator configured to modulate the excitation light to produce a modulated light; a pulse compressor configured to compress a pulse of the modulated light to produce a pre-compensated light; a beam scanner configured to raster scan the pre-compensated light on a sample; a detector configured to receive a light signal from the sample and produce a detection signal; and a lock-in amplifier configured to receive the detection signal and perform an electronic heterodyne amplification of the detection signal.

A leakage detection device for detecting leakage of compressed gas includes a microphone that collects an ultrasonic signal which is converted into an electrical signal and outputted. Lock-in amplifiers extract one of the electrical signals having a specific frequency corresponding to a leakage and a calculation circuit calculates a physical amount corresponding to an amplitude value of the signal having the specific frequency. A notification device provides a notification to a user depending on the physical amount calculated by the calculation circuit.

The invention discloses a methane telemetering imaging system and method based on an active infrared absorption spectrum and a fast reflector, and the system comprises a main control module, a laser driver, a laser, a detector, an off-axis parabolic reflector, a voice coil fast reflector, and a distance measurement module. The laser driver controls the laser device to emit modulated laser, the voice coil fast reflecting mirror controls the angle of emergent laser, the semiconductor photoelectric detector receives an echo optical signal, converts the echo optical signal into an electric signal and sends the electric signal to the main control module, and the main control module further completes signal analog-to-digital conversion through an analog-to-digital converter. And a digital lock-in amplifier is used to demodulate the signal to respectively obtain a first harmonic and a second harmonic. The method has the advantages of high imaging speed, high spatial resolution, high detection sensitivity and the like.

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.

This invention provides a method for measuring dielectric constant based on oblique incidence light reflection difference technology. The probe light emitted by the laser 1 is converted into p-polarized light by the polarizer 2, and then modulated into p-polarized light and s-polarized light by the photoelastic modulator 3. The p-polarized light and s-polarized light are emitted alternately at a frequency of 50 kHz, and after passing through the phase shifter 4, a fixed phase difference is generated. Then, the light is focused by the first lens 5 and obliquely incident on the surface of the sample 6 to be tested, with the incident range between 50° and 60°. The signal light reflected from the surface of the sample 6 to be tested is incident on the analyzer 9 after passing through the second lens 8. The analyzer 9 is used to zero the fundamental frequency signal of the system. The signal light after passing through the analyzer 9 is absorbed by the photodetector 10 and converted into an electrical signal. The electrical signal is demodulated by the first lock-in amplifier 11 and the second lock-in amplifier 12 into a DC signal, a fundamental frequency signal I (Ω), and a harmonic signal I (2Ω). The demodulated signal is acquired and processed by the data acquisition and processing unit 13.

The invention relates to the technical field of optical detection, in particular to a buried structure detection device based on laser-induced ultrasonic waves, which comprises a laser, a light splitting element, a light modulation module, a beam combining element, a light sensitive element and a lock-in amplifier, and is characterized in that pulse laser generated by the laser is divided into pump light and detection light; after the light modulation module periodically modulates the pump light, the pump light and the probe light are confocal on the surface of a to-be-detected sample through the beam combining element; the pump light excites ultrasonic waves, and the ultrasonic waves are reflected by the metal grating in the sample to form a sound wave induction interface grating; the detection light is received by the photosensitive element after being diffracted and is converted into an electric signal; a lock-in amplifier extracts a synchronized diffracted signal from the signal using the modulation frequency. The method can effectively penetrate through the opaque material layer to detect the completely buried alignment mark, overcomes the limitation of the traditional optics and the existing laser ultrasonic technology, and improves the detection precision and reliability of the deep structure.

The invention discloses a drug coating state online monitoring method and device, and the method comprises the steps: employing an optical fiber femtosecond laser as a light source core, and transmitting femtosecond laser for detection; a terahertz time-domain spectrometer is adopted as a detection instrument, and a terahertz probe of the spectrometer is fixed to the outer side of a mesh of a to-be-detected sample coating pan; the time delay of the probe light emitted by the fiber femtosecond laser is adjusted by controlling the fiber time delay line, and the signal emission and reception of the terahertz probe are synchronously controlled; the terahertz probe transmits a signal to a to-be-detected sample and converts a received terahertz return signal into an electric signal, and the electric signal is amplified by the lock-in amplifier and then transmitted to the terminal equipment; and the terminal equipment generates terahertz time-domain spectroscopic data according to the received signal, and calculates the coating thickness of the to-be-detected sample. The method and the device can solve the problems that the measurement result is lagged and the coating thickness distribution state and the uniformity cannot be detected in real time in the prior art.

The invention discloses a full-scale deep sea dissolved CH4 in-situ sensor, and belongs to the technical field of deep sea dissolved gas in-situ detection, and the full-scale deep sea dissolved CH4 in-situ sensor comprises a circuit system unit, a trace gas measurement cavity unit and a water-gas separation unit; the circuit system unit comprises a microcontroller, a frequency synthesizer, a summator, a laser, a laser driving circuit, two analog lock-in amplifiers, two pre-amplifiers and two analog-to-digital converters; the trace gas measuring cavity unit comprises a trace gas measuring cavity, an optical fiber collimator, a tuning fork, a coaxial micro resonant tube, a temperature, humidity and air pressure sensor, a photoelectric detector, two electromagnetic valves and a micro air pump; the water-gas separation unit comprises a base, a sintered block, filter paper and a water-gas separation membrane; the miniaturized deep sea dissolved CH4 high-sensitivity full-range in-situ sensor with low gas consumption has the advantages of high sensitivity, full range, low gas consumption, strong anti-interference capability, fast response, low power consumption, small size and the like.

The utility model relates to quantum chip port impedance test technical field especially for a kind of quantum chip port impedance test device, including test board, the one side of test board is fixedly connected with electromagnetic shield side plate, the one side of electromagnetic shield side plate is slidably connected with electromagnetic protection component, the outside of test board is slidably connected with electromagnetic shield cover, the inside of electromagnetic shield cover is installed with electromagnetic shield adjusting component;Electromagnetic protection component includes metal electromagnetic shield plate, the both sides of metal electromagnetic shield plate are fixedly connected with composite electromagnetic shield plate, the outside of composite electromagnetic shield plate is fixedly connected with connecting plate, and cable perforation is established in the bottom of connecting plate, in the utility model, effectively block outside electromagnetic signal interference, promote shielding effect, device can adapt to different models of lock-in amplifier and relay, effectively expand the range of use, ensure that lock-in amplifier receives pure signal, improve the accuracy and reliability of test data.

The application discloses a multi-stage coupling amplification photoacoustic spectrum greenhouse gas measuring system and method, and belongs to the technical field of trace gas measurement. The measuring system comprises a micro multi-pass variable-diameter T-shaped photoacoustic cell, a gas distribution system, a DFB laser, and a data acquisition and processing system. Reflectors one and two are arranged at the two side windows of the micro multi-pass variable-diameter T-shaped photoacoustic cell. The gas distribution system introduces the to-be-measured gas into the gas chamber of the micro multi-pass variable-diameter T-shaped photoacoustic cell. The DFB laser generates modulated laser, which enters the micro multi-pass variable-diameter T-shaped photoacoustic cell through the collimating lens from the incident hole of the reflector one, and is reflected back and forth between the reflectors two, so that multi-stage coupling amplification photoacoustic signals are generated, and then the signals are demodulated by a lock-in amplifier, and enter the data acquisition and processing system. Through multiple reflections in the micro multi-pass variable-diameter T-shaped photoacoustic cell, the interaction between the laser and the gas is enhanced, so that the monitoring of the methane gas concentration is more accurate and reliable.

The invention discloses a laser-induced fluorescence system and method for measuring interaction between argon plasma ions and neutral ions, and belongs to the technical field of plasmas. According to the system, two semiconductor lasers are adopted to generate lasers of 667.91 nm and 668.61 nm respectively, the wavelength is monitored in real time through a wavelength meter, after pulse modulation is conducted on the lasers through an acousto-optic modulator, the lasers are coupled to enter a single-mode optical fiber and are guided to enter a plasma to-be-detected area, and argon ions and neutral particles are excited to generate fluorescence. According to the system, two fluorescence collection modules are respectively aligned with the same measurement point to collect ion and neutral fluorescence signals, and after demodulation by a lock-in amplifier, Doppler frequency shift and line width change of a fluorescence spectrum are analyzed by a processor, so that speed and temperature distribution of ions and neutral particles is obtained. According to the invention, non-intrusive synchronous measurement with high spatial resolution is realized, and the problem of insufficient measurement precision in the prior art is effectively solved.

The invention provides a self-excitation type Mx rubidium atom magnetometer device and a working method, the self-excitation type Mx rubidium atom magnetometer device comprises an atom magnetometer probe and an atom magnetometer driving circuit, and the atom magnetometer probe is connected with the atom magnetometer driving circuit; the atom magnetometer probe comprises a VCSEL laser tube, an electro-optical modulator, a 1 / 4 slide, a rubidium atom gas chamber and a photosensitive tube. The atom magnetometer driving circuit comprises a lock-in amplifier, a phase shifter, an EOM driver and a laser tube driver. According to the invention, the atom magnetometer driving circuit synchronously modulates the polarization state and the light intensity of the pumping laser in the rubidium atom magnetometer to form an auto-excitation feedback loop, so that the problem that the radio frequency magnetic field feedback auto-excitation working mode adopted by the traditional Mx magnetometer is not suitable for the rubidium atom magnetometer is solved; and an instable feedback loop is formed.

The application discloses a wide-band micro-region semiconductor photocurrent imaging system and method, and belongs to the technical field of semiconductor testing. The system comprises a temperature adjusting module, a picosecond pulse laser output module, an optical chopper, a microscopic imaging module, an electric piezoelectric displacement table and a lock-in amplifier. The temperature adjusting module is used for adjusting the temperature of a semiconductor device to be tested to 4K to 296K. The picosecond pulse laser output module is used for outputting a pulse laser beam in a wave band of 430nm to 2000nm. The optical chopper is used for modulating the laser beam into an optical pulse signal with a fixed modulation frequency. The lock-in amplifier is used for applying a bias voltage to the semiconductor device to be tested and collecting a photocurrent signal under the fixed modulation frequency. The electric piezoelectric displacement table is used for moving the semiconductor device to be tested point by point under a low-temperature environment. The microscopic imaging module is used for synchronously acquiring a surface topography image and constructing a photocurrent spatial distribution map. The application solves the technical problem that the current technology cannot simultaneously realize multi-wavelength excitation, weak signal extraction and micro-region spatial resolution imaging under an extremely low-temperature environment.

The present application relates to a kind of magnetoelectric coupling test methods of high sensitivity, the method carries out deep integration to series array, dynamic method and lock-in amplifier, comprising: preparing multiple magnetoelectric sensor units with substantially consistent performance on a single chip and electrically in series, one unit top electrode connects the bottom electrode of next unit;Interchangeable magnetic field and adjustable DC magnetic field are applied, and working point is set in magnetoelectric voltage coefficient linear response region by sweep frequency sweep field;With the frequency of alternating magnetic field as reference, phase-sensitive detection demodulation is carried out to series output signal by lock-in amplifier;According to output voltage, alternating magnetic field and material thickness, magnetoelectric voltage coefficient and equivalent magnetic noise are calculated.The method fundamentally improves signal-to-noise ratio, breaks the sensitivity bottleneck in weak signal detection of traditional method, not only strengthens front-end signal, but also better realizes noise suppression, improves applicable scope, improves practicability.

This invention relates to a method and apparatus for measuring the magnetostriction coefficient of magnetic thin film materials based on Fabry-Perot optical interferometry readout coupled with a nanomechanical resonator. The apparatus includes a Si / SiO2 substrate, a magnetic field source, a measurement cavity, an interferometric microscopy system, and an analysis and control component. The Si / SiO2 substrate comprises a Si layer, a SiO2 layer, and a gate. A hole extending from the gate to the Si layer is provided on the Si / SiO2 substrate. The magnetic thin film material to be measured is disposed at the opening of the hole, forming a suspended membrane, which, together with the Si / SiO2 substrate, constitutes a Fabry-Perot interferometer. The analysis and control component includes an AC signal generator, a phase-locked loop (PLL), and a lock-in amplifier. The AC signal generator is electrically connected to the magnetic field source to control the magnetic field source to generate a frequency-adjustable alternating magnetic field. The PLL is used for frequency tracking. The lock-in amplifier is used for differential measurement. Compared with existing technologies, this invention is applicable to the characterization of the magnetostriction coefficient of single-layer / few-layer van der Waals magnet thin film materials and has the advantage of high sensitivity.

The invention relates to a magnetic flux modulation type high-intensity magnetic field measuring device and method based on self-reference, and relates to the field of metering and testing instruments. Comprising the steps that a motor drives a transmission shaft to control an induction coil to rotate in a strong magnet, two paths of homologous and synchronous induced electromotive force E1 are generated, the induced electromotive force E2 is output through a twisted pair in a conductive slip ring and input into a first signal conditioning module and a second signal conditioning module respectively, and the conditioned induced electromotive force E1 is input into a precise voltage division network for voltage division; the induced electromotive force after voltage division is input into a lock-in amplifier reading system through a first voltage follower to serve as a signal to be measured; the conditioned induced electromotive force E2 is synchronously input into a waveform shaping circuit to be converted into a square wave signal with a fixed amplitude value, the square wave signal after conversion is input into a phase-locked amplifier reading system through a second voltage follower to serve as a reference signal, and the phase-locked amplifier reading system carries out data reading on the induced electromotive force. According to the invention, the problem that the high-intensity magnetic field is difficult to accurately measure and trace is solved.