23 results about "Optical chopper" patented technology

The invention relates to the technical field of low-temperature infrared radiation detection, and provides low-temperature infrared radiation detection equipment, which comprises a vacuum cold box, an infrared detection device, a control system and a signal processing system, and is characterized in that the infrared detection device comprises an infrared window sheet, an optical shutter, an optical lens, an optical chopper and an infrared detector; the optical chopper adjusts an infrared radiation signal emitted by a target object to a predetermined frequency, and the infrared detector receives the infrared radiation signal and converts the infrared radiation signal into an electric signal; the signal processing system comprises a pre-amplifier, a lock-in amplifier, a signal processing unit and a display unit, the pre-amplifier amplifies the electric signals output by the infrared detector, and the lock-in amplifier extracts signals corresponding to the preset frequency from the electric signals amplified by the pre-amplifier and amplifies the signals. Through the arrangement, the optical chopper, the pre-amplifier and the lock-in amplifier are combined, so that the measurement precision of infrared detection is effectively improved.

The invention discloses a system for measuring high-temperature infrared emissivity of a solar heat collector, which relates to the technical field of emissivity measurement and is technically characterized in that the system realizes uniform distribution of surface temperature of a sample through a micro-nano structure solar heat collection heating module, and covers a high-temperature range of 100-1200 DEG C in combination with PID temperature control and a rotating platform; an optical chopper is used for modulating the frequency of an optical signal, and a lock-in amplifier is combined to extract a weak signal, so that the signal-to-noise ratio is improved to 105 magnitude, and radiation intensity detection as low as 10 <-3 > W / cm < 2 >. Sr. Mu m is supported; the system also ensures that the standard radiation module realizes traceability transmission of temperature and radiation intensity by periodically calibrating the standard black body and the auxiliary black body, and ensures that the measurement error is less than or equal to + / -1%; the Fourier infrared spectrometer covers the wave band of 0.8-25 microns, a beam splitter and a refrigeration type detector are combined, the spectral resolution reaches 0.5 cm <-1 >, and complex spectral characteristics at high temperature can be accurately analyzed.

The invention discloses a reflective pumping detection nondestructive testing device and method capable of saturatively absorbing uniformity in a mirror surface. The device is based on a wavelength degeneracy pumping-detection principle, and comprises a femtosecond laser source, a beam splitter, an optical delay line, a double-frequency optical chopper, a two-dimensional precision translation stage, a coaxial focusing system, a spatial filtering diaphragm arranged in a reflection light path, a photoelectric detector, a lock-in amplifier and a signal processing unit. According to the method, different point positions of a sample are accurately positioned through a two-dimensional translation stage, a nonlinear differential reflectance dynamic curve of each point is measured under low power, the maximum differential reflectance and the carrier lifetime are extracted as characteristic parameters, the spatial relative standard deviation of the characteristic parameters is calculated, and lossless and quantitative in-plane uniformity evaluation is realized. According to the method, the interference of the pump light is effectively filtered through the space filtering diaphragm, the signal-to-noise ratio is remarkably improved in combination with the phase-locked amplification technology, and the problem that the nonlinear optical performance uniformity of the saturable absorber mirror cannot be quantitatively evaluated through a traditional method is solved.

The invention discloses a radiation intensity measurement method of an infrared radiation simulation source system, and belongs to the technical field of infrared radiation characteristic measurement. The method comprises the following steps: firstly, performing radiometric calibration operation on an infrared radiation simulation source system and an infrared detector; a medium-wave infrared optical system and an infrared detector are used for receiving infrared radiation signals, and continuous radiation is converted into alternating signals through modulation of an optical chopper, so that the measurement signal-to-noise ratio is increased. Collected alternating signals are processed by the filtering gain amplification circuit so as to enhance signal stability. And then dynamic denoising and state estimation are carried out on measured data by adopting a Kalman filtering algorithm, and nonlinear error compensation is carried out in combination with a medium-wave infrared radiation coefficient correction algorithm, so that a high-precision radiation intensity correction coefficient is obtained. Compared with a traditional method, the self-adaptive filtering and radiation intensity correction technology is combined, the measurement precision and the real-time performance are improved, and the method can be widely applied to the fields of infrared optical testing, target characteristic analysis and radiation measurement.

A system may include a broadband light source emitting polarized light that is polarized to two orthogonal polarization states, multiple beam splitters for combining and splitting the polarization states, and interferometric cell for creation of interference patterns with respect to a sample surface, lenses of appropriate design that focus the polarized light at predefined locations, and sensors that analyze the polarized light as a function of angle and wavelength. The system may also include a controller configured to modulate the reference arm through operation of an optical chopper and allow for different data analysis modes to be used on the system produced data.

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.

To obtain a flame detector testing device that can achieve stable operational test accuracy when conducting operational tests of flame detectors in various operational test environments. [Solution] The system comprises a light source that outputs light containing infrared and visible light components as continuous irradiation light, an optical chopper that generates flashing light by performing a chopping operation that repeatedly passes / blocks the continuous irradiation light at a chopping frequency corresponding to the flickering frequency of a flame, and a control unit that comprehensively controls the light source and the optical chopper. The control unit has a mode switching function that allows selection between a lighting mode, which generates steady light by controlling the light source to be ON and performing stop position control to stop the optical chopper at a position where the continuous irradiation light passes through, and a flashing mode, which generates flashing light by controlling the light source to be ON and performing chopping control to perform the chopping operation.

The invention discloses a high-stability liquid line intensity terahertz radiation generation device which comprises a femtosecond laser, an optical chopper, a first off-axis parabolic mirror, a liquid line generation unit, a second off-axis parabolic mirror, a third off-axis parabolic mirror, an attenuation piece, a low-pass filter and a terahertz energy detector. Wherein the liquid line generation unit integrates a liquid circulation subsystem and a gas power compensation module composed of a gas storage tank and a pressure regulating valve, and the module provides continuous gas pressure for a liquid flow path in the power neutral period of the peristaltic pump, so that the flow jitter and surface turbulence of a liquid line are effectively inhibited; the problems of terahertz signal fluctuation and intensity attenuation caused by liquid line instability are solved, high-intensity and high-repetition-frequency terahertz radiation output with stability improved by about four times is finally achieved, and a feasible scheme is provided for practicability of a liquid terahertz source.

The application provides a chopper for optical pulse modulation, an optical pulse modulation method, a multi-beam pulse-based super-resolution optical imaging device and a multi-beam pulse-based super-resolution optical imaging method. The chopper comprises an optical chopper plate provided with a light transmission area. The light transmission area is arranged at a periphery of a center point on the optical chopper plate, and the light transmission width of the light transmission area is different along the extension direction from the center point to the outer edge of the optical chopper plate. The chopper provided by the application can simultaneously modulate multiple incident light beams with different wavelengths into multiple light beam pulse sequences with specific frequencies, different duty cycles and different light emission sequences.

The present application provides an endoscope device capable of eliminating OCT speckle noise in real time, which comprises an OCT imaging system and an endoscope probe; the endoscope probe is driven by a stepping drive assembly, the OCT imaging system comprises an OCT imaging catheter and an optical chopper arranged in the OCT imaging catheter; a single-mode optical fiber is arranged in the OCT imaging catheter, the single-mode optical fiber is connected with a self-focusing lens through a sleeve, and the optical chopper is arranged behind the self-focusing lens; a rotating device is connected with the optical chopper, and a micro-reflection prism is arranged behind the optical chopper; after the light beam of the single-mode optical fiber passes through the self-focusing lens, the light beam is modulated by the optical chopper and then turned to a detection area through the micro-reflection prism; the spatial distribution of the light beam is changed by using the chopper, the modulation of speckle noise is realized, and the image quality is significantly improved without reducing the spatial resolution.

The invention relates to the field of dynamic testing of materials, and particularly discloses an infrared temperature measuring device for a Hopkinson bar. The device comprises an incident bar, a transmission bar, a sample, a dust cover, an infrared filter, two off-axis parabolic mirrors, an optical chopper, a light splitting cube, a laser, a HgCdTe infrared sensor, a signal amplifier and an oscilloscope. The device is provided with a dust cover and is vacuumized to isolate environmental interference; an off-axis parabolic mirror is adopted to form a focusing light path to collect infrared radiation of the sample; the light splitting cube is used for coupling visible light of the laser and infrared light of the sample, so that coaxial accurate positioning of a temperature measuring point is realized; sensor calibration is carried out by combining an optical chopper; and finally, an infrared signal is converted into an electric signal through the HgCdTe infrared sensor, and the temperature change is recorded by the oscilloscope in real time after the electric signal is amplified. The device realizes real-time non-contact accurate measurement of the temperature of the sample in the dynamic loading process.

The present invention discloses a photoelectrochemical detection device and application based on radiation modulation, belonging to the technical field of photoelectrochemical sensing and biological detection; a detection device applicable to the detection of alpha-fetoprotein, comprising a photoelectrochemical biosensor and a photoelectrochemical test device; the photoelectrochemical biosensor includes an ATA thin film electrode; the ATA thin film electrode includes an FTO substrate; a Au film layer is provided on the upper surface of the FTO substrate, and a TiO2 film layer is provided on the upper surface of the Au film layer; a AuNPs layer is deposited on the TiO2 film layer; the photoelectrochemical test device includes an optical chopper connected to a lock-in amplifier; the lock-in amplifier is connected to a low-pass filter; the optical chopper is arranged between the light source and the photoelectrochemical biosensor; the photoelectrochemical biosensor is connected to the low-pass filter through an electrochemical workstation; the present invention uses lock-in amplification combined with the ATA thin film electrode to enable the detection of the analyte to have a lower detection limit and a larger detection range.

The application claims a photothermal detection device for non-invasive glucose detection, comprising a quantum cascade laser, a DFB detection laser, an optical medium, a dove prism, a parabolic mirror, an optical chopper, an optical polarizer, a photodetector, a lock-in amplifier, a data acquisition card and a computer, and innovatively proposes an interferometric intensity demodulation-based photothermal detection technology. The miniaturized dove prism absorption cell structure is combined with the FPE (Fabry-Perot cavity), so that it has better vibration resistance. The device adopts a non-invasive detection method, can detect the blood glucose concentration in real time without blood sampling, reduces the pain of patients, improves the convenience and comfort of detection, and has important significance for the development of biological medical detection.

The present invention provides a laser time-frequency conversion observation system and method based on hyperspectral imaging. The system includes an optical platform and a femtosecond laser, a pulse signal generator, a reflector, a beam splitter, a laser optical chopper, a white light crystal, a beam reduction and expansion subsystem, a beam homogenization and spot homogenization device, a focusing lens, an aperture, an optical power meter, an optical filter, an optical delay translation stage, a pulse shaping subsystem, a sample loading subsystem, a hyperspectral camera capture subsystem, and a computer control subsystem. The present invention uses a hyperspectral camera to replace a traditional CCD camera to perform optical and spectral imaging of the instantaneous evolution state of the surface of the sample to be measured, compensating for the limited observation capability of traditional optical pump-detection technology due to the optical diffraction limit, and performing real-time optical imaging and two-dimensional spectral imaging of the surface of the sample to be measured when excited by the femtosecond laser.

According to the femtosecond transient absorption and nanosecond transient absorption integrated system and the test method thereof provided by the invention, femtosecond transient absorption and nanosecond transient absorption are coupled together to work, and a first optical chopper and a second optical chopper are introduced to modulate repetition frequencies of a femtosecond laser and a nanosecond laser; the time range of the nanosecond transient absorption test is shortened or prolonged, the measurement of fs-TA and ns-TA can be completed at one time, and the measurement from femtosecond level to millisecond level is fully covered.

The present invention discloses a method for measuring the radiation intensity of an infrared radiation simulation source system, which belongs to the technical field of infrared radiation characteristic measurement. First, a radiation calibration operation is performed on the infrared radiation simulation source system and the infrared detector; a medium-wave infrared optical system and an infrared detector are used to receive the infrared radiation signal, and the continuous radiation is converted into an alternating signal through optical chopper modulation to improve the measurement signal-to-noise ratio. The collected alternating signal is processed by a filter gain amplifier circuit to enhance signal stability. Subsequently, a Kalman filter algorithm is used to perform dynamic denoising and state estimation on the measurement data, and a medium-wave infrared radiation coefficient correction algorithm is combined to perform nonlinear error compensation, thereby obtaining a high-precision radiation intensity correction coefficient. Compared with traditional methods, the present invention combines adaptive filtering and radiation intensity correction technology to improve measurement accuracy and real-time performance, and can be widely used in infrared optical testing, target characteristic analysis and radiation metrology.

The invention discloses an optical frequency modulation and same-frequency electric signal output device for laser pulses, and relates to the technical field of optical frequency modulation. According to the device, an optical chopper is arranged between two diaphragms, fan blades of the optical chopper are covered with film coating layers, laser is reflected after irradiating the film coating layers on the fan blades, the repetition frequency of the laser is adjusted by controlling the rotating speed of the optical chopper, and laser pulses of different frequencies passing through the diaphragms are obtained. The optical sensor is arranged on a laser reflection path of the optical chopper and can receive reflected laser pulses to form light currents through the photoelectric effect, and the light currents are converted into electrical pulse signals with the same frequency as the laser pulses passing through the diaphragm through the signal collecting and converting circuit and then output. According to the invention, the adaptability of optical frequency modulation is improved, and the reflected laser is utilized to form an electric signal with the same frequency as the laser pulse passing through the diaphragm so as to be used for device control because the passing and reflecting frequencies of the laser by the optical chopper are the same.

The invention discloses a terahertz wave signal intensity detection method, device and equipment and a medium, and belongs to the field of terahertz weak signal detection.The method comprises the steps that a terahertz wave signal is modulated into a periodic intermittent optical signal through an optical chopper according to a preset chopper modulation frequency; the periodic intermittent optical signal is converted into a voltage signal through a terahertz probe; amplifying the voltage signal through an amplification conditioning circuit, and converting the amplified voltage signal into a digital signal through an analog-to-digital acquisition circuit; through the MCU chip, fast Fourier transform is combined with chopper modulation frequency, the digital signal is analyzed, and the intensity of the terahertz wave signal is obtained. Therefore, by implementing the application, the problems of high hardware cost and low detection speed in the terahertz wave signal intensity detection process can be solved.

The present invention discloses a high-sensitivity photothermal deflection spectrum test device and calibration method, comprising mutually perpendicular detection light path and pump light path, wherein a pump light source, a monochromator, an optical chopper, a pump light lens group and an absorption cell are sequentially arranged along the pump light path; a detection light source, a spatial filtering system, a detection light focusing lens, an absorption cell and a position-sensitive detector are sequentially arranged along the detection light path; the signal output end of the position-sensitive detector is connected to the signal input end of a phase-locked amplifier, and the output end of the phase-locked amplifier is connected to a computer; the signal control end of the monochromator is connected to a computer, and the signal output end of the optical chopper is connected to the signal input end of the phase-locked amplifier; the spatial filtering system comprises a spatial filtering focusing lens, a micropore, a spatial filtering collimating lens and an aperture arranged along the light path. By utilizing the present invention, the test sensitivity of the photothermal deflection spectrum can be improved, so that the test accuracy of the thin film absorbance can reach 10 <supgt;‑5< / supgt;~10<supgt;‑4< / supgt;。

The invention discloses a single-pixel long-wave infrared spectrum detection system and method based on a metasurface filter. The system comprises a to-be-measured object module, an optical modulation module, a signal acquisition module and a data processing module, the to-be-measured object module irradiates the to-be-measured object through spontaneous radiation of the to-be-measured object or a stable infrared radiation light source provided by a blackbody radiation source; the optical modulation module is integrated with a binary coding mask optimized by a genetic algorithm and a 5 * 5 array type metasurface filter, so that rapid switching of 12 low-correlation coding modes is realized; the signal acquisition module is focused by an infrared lens and modulated by a band-pass optical filter and an optical chopper, optical-electric conversion is completed by a single-pixel infrared detector, and a signal is amplified by a lock-in amplifier; and the data processing module realizes spectrum restoration through a neural network, and completes substance classification in combination with recursive feature elimination and secondary discriminant analysis. The device has the characteristics of high luminous flux, high signal-to-noise ratio, high efficiency, high resolution, low cost and small size, and is suitable for on-site rapid screening.

The invention relates to a tunable terahertz radiation device and method based on metal wire liquid column coupling, and the device comprises a femtosecond laser which is used for outputting pumping laser with high repetition frequency; the optical chopper is used for chopping the pumping laser to the required repetition frequency; the metal wire liquid injection coupling structure comprises a metal wire and a liquid column, and a metal wire liquid column coupling area of a local liquid film is formed on the surface of the metal wire based on the synergistic effect of the metal wire and the liquid column; the chopped pumping laser pulse is focused to a metal wire liquid column coupling area through a first off-axis parabolic mirror, the relative position of the metal wire liquid column coupling area and the pumping laser focus is finely adjusted, and stable terahertz radiation output is achieved; and the pulse width of the pump laser output by the femtosecond laser is changed, so that the strong terahertz source output with tunable frequency is realized. Compared with the prior art, strong terahertz output with high energy and high repetition frequency can be realized, the tunability of the terahertz frequency spectrum is expanded, and remarkable advantages are achieved.

A method for producing light of a specified wavelength includes irradiating a dye solution present in a cuvette with a semiconductor diode laser source to emit laser light. A system for producing a light of a specified wavelength includes a semiconductor diode laser source, an optical chopper, a cylindrical lens, a dye preparation unit, a grating, and a dye solution pump. The dye preparation unit includes a rotator and a cuvette loaded with a dye solution, which includes a dye solution. The dye solution comprises a natural oil selected from moringa, avocado, almond, castor, pumpkin, lemon oils, or combinations thereof, with dissolved dye at concentrations of 1-3 μg / mL. This configuration enables enhanced amplified spontaneous emission intensity at elevated temperatures while maintaining photochemical stability.

The application discloses a target distance and speed measurement system and method based on radio frequency modulation direct detection laser radar, and belongs to the technical field of target distance and speed measurement.The application solves the problem that the existing direct detection laser radar based on radio frequency phase modulation technology cannot measure the distance information of a target.The application introduces radio frequency technology into the direct detection laser radar by means of laser radio frequency modulation and demodulation technology, and utilizes a beam splitter and an optical chopper to process the echo signals of a reference target and a detection target, so that the detection performance of the target distance and speed can be improved, and the problem that the existing method cannot measure the distance information of the target is solved.Further, the measurement method of the application utilizes the frequency information of the radio frequency signal, and avoids information waste.The method of the application can be applied to the technical field of target distance and speed measurement.