15 results about "Fourier transform spectrometers" patented technology

The invention discloses a gas detection precision improving method based on a multi-algorithm fusion framework. A photonic crystal resonant cavity and a tunable band-pass filtering structure are integrated in a Fourier transform spectrometer light path; collecting a wide-spectrum light intensity signal, and constructing a spectral signal database in combination with the enhancement characteristic and the filtering characteristic of the resonant cavity; zero calibration and dynamic baseline deduction operation are carried out, and self-adaptive variational mode decomposition and wavelet transform are adopted to carry out signal denoising on the spectral signals; an environment compensation model is established, and an Arrhenius type correction factor is adopted to suppress water vapor cross interference; constructing an RLS and fuzzy control combined hybrid adaptive filter; separating aliasing spectral signals by adopting a non-negative matrix factorization algorithm; establishing a quantitative relation model; in the online concentration prediction process, the initial concentration value is subjected to recursive optimization by using a hybrid adaptive filter, the deviation is continuously corrected through an environment compensation model, and an accurate concentration value is output. The method can significantly improve the accuracy and stability of multi-gas detection.

The application discloses a double-waveband Fourier transform spectrometer, and relates to the technical field of spectrometers. The spectrometer comprises a first Michelson interference optical path assembly and a second Michelson interference optical path assembly. The first Michelson interference optical path and the second Michelson optical path use the front and back surfaces of a same moving mirror as phase modulators. The coating materials of the front and back surfaces of the moving mirror are different. The reflected light beams of the front and back surfaces of the moving mirror have different wavebands. The application improves the signal quality of the spectrometer when detecting wavebands or measuring across wavebands through the double-path Michelson interference optical path assembly of the shared moving mirror.

The invention discloses a Fourier transform spectrometer system of a multiband light source structure, which comprises a multiband light source conveying unit used for transmitting light of multiple bands; the collimation unit is used for collimating the light transmitted by the multiband light source conveying unit; the light beam combining unit is used for forming a combined light beam; the light splitting unit is used for respectively transmitting and reflecting the plurality of beams of light; the reflector unit is used for receiving the multiple beams of light transmitted or reflected by the light splitting unit and retroreflecting the multiple beams of light in the incident direction of the multiple beams of light; and the detection unit is used for converging the multiple beams of light reflected by the reflector unit and receiving and detecting the converged multiple beams of light. According to the invention, input wavebands can be selected and multiple wavebands can be measured simultaneously, and near-infrared light and far-infrared light can be measured simultaneously, so that the detection efficiency is improved.

The application discloses an equal-wavenumber division waveband noise reduction method for an infrared Fourier transform spectrometer, and is applied to fine spectral detection with wide spectral range and ultrahigh resolution. When designing a low-temperature infrared Fourier transform spectrometer, a low-temperature filter wheel is arranged in an optical path in front of a detector, and the low-temperature filter wheel is driven by a low-temperature motor. A plurality of filters are arranged on the filter wheel, the central wavelengths of the filters are different, the central wavelength intervals are different, the central wavelengths and the bandwidths of the filters are designed according to equal central spectral intervals, each filter has a narrow bandwidth, and according to a spectral range of a required detection target, a corresponding filter is selected to realize spectral detection with ultrahigh spectral resolution of a concerned spectral range. For the infrared Fourier transform spectrometer with high spectral resolution and wide spectral bandwidth, the measurement brings the advantage of reducing noise caused by out-of-band photons on the detector, and low temperature of the filter reduces infrared background and photon noise caused by the filter body.

Embodiments of the present disclosure relate to a technique for high resolution and wide format spectrometers. In illustrative embodiments, an inverse image slicer converts a linear field of view to a grid shape, allowing the interferometer of a Fourier transform spectrometer to operate over a narrow field of view range, thereby increasing the average spectral resolution of the spectrometer.

The invention provides a Fourier transform spectrometer synchronous data acquisition device and a control method thereof, and the device comprises an interference signal conditioning module which is used for carrying out the synchronous amplification of a plurality of interference signals, and obtaining an amplified multi-source interference signal; the clock management module is used for performing fan-out buffering on the adjustable sampling clock signal to obtain a multi-channel ADC sampling clock signal; the multi-channel ADC sampling module is used for synchronously sampling the amplified multi-source interference signal according to a multi-channel ADC sampling clock signal to obtain multi-channel interference signal sampling data; and the master control FPGA module is used for caching the multi-channel interference signal sampling data and sequentially performing adaptive filtering, zero crossing point detection, difference reconstruction, timestamp addition and data framing processing on the multi-channel interference signal sampling data to obtain framed interference data. According to the device, the reliability of data acquisition of the multi-channel Fourier transform spectrometer is improved.

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

A Fourier transform spectrometer 100 includes an interferometer 10, which includes a fixed mirror 11, a movable mirror 12, and a detector 101, wherein: the mirrors 11 and 12 are positioned parallel to each other and form an optical cavity; the movable mirror 12 is operable to move relative to the fixed mirror 11 to change the size of the optical cavity; a first mirror in the mirrors is positioned such that light 14 received from a sample passes through the back of the first mirror into the optical cavity; the detector 101 is positioned and operable to detect light that has passed through the back of a second mirror in the mirrors and exits the optical cavity and outputs an interferogram; and the mirrors 11 and 12 are spaced apart from each other such that the movable mirror is positioned or can be moved to a position in which at least two paths 16, 31 of the received light 14 reflected within the interferometer toward the detector 101 have equal lengths.

The application discloses a Fourier transform spectrometer based on a multi-channel waveguide, which comprises a grating coupler, wherein probe light is coupled into a waveguide structure through the grating coupler after passing through a measured sample, the waveguide structure comprises a multiple beamsplitter, an active Mach-Zehnder interferometer array and a high-speed photodetector array; the multiple beamsplitter is used for splitting the incident probe light and then the split light is incident into the active Mach-Zehnder interferometer array, each channel of the multiple beamsplitter corresponds to a group of active Mach-Zehnder interferometers; each channel of the active Mach-Zehnder interferometer array is connected with the high-speed photodetector array through a transmission waveguide. The application has the advantages that the mature Mach-Zehnder interferometer technology is used to reduce the process complexity of the existing Fourier spectrometer structure and improve the process consistency.

The invention discloses a moving mirror scanning device for a high-resolution Fourier transform spectrometer, and relates to the technical field of optical interference measurement. The moving mirror scanning device for the high-resolution Fourier transform spectrometer comprises a moving mirror scanning device provided with a moving mirror end corner reflector, and a two-stage driving module composed of a power assembly and a voice coil motor. The position detection module comprises a photoelectric switch used for limiting and a laser interference system used for real-time feedback. The control module carries out basic scanning by coordinating first-stage driving and carries out closed-loop adjustment on output of the voice coil motor according to deviation calculated in real time through laser interference signals, long-stroke precise scanning is achieved through two-stage cooperative driving, the power assembly provides main traction, and the voice coil motor carries out real-time closed-loop fine adjustment according to the laser interference signals; the contradiction between the speed and the precision of a traditional single driving mode is overcome, transverse movement and vibration are effectively restrained through a spring steel elastic piece and a precise guiding structure, and the straightness of a movement track is guaranteed.

This invention relates to the field of infrared interference smoke screen technology, and particularly to a composite detection device and method for the infrared transmittance of interference smoke screens in a vacuum. The device includes: a vacuum tank, a vacuum pump, an electronic vacuum gauge, a temperature sensor, a humidity sensor, a target temperature simulation module, a simulation module controller, an interference smoke screen sample module, an ignition head, an igniter, a Fourier transform spectrometer, an infrared radiometer, an infrared thermal imager, a three-way solenoid valve, pipes, a filter, a flow meter, a computer module, a programmable logic controller (PLC), and a power supply. The Fourier transform spectrometer, infrared radiometer, and infrared thermal imager are used as composite transmittance testing methods to achieve the effectiveness of interference smoke under composite testing technology. A testing device with the same target temperature simulation module and the same testing environment is constructed to ensure consistency in the parameter acquisition environment. By combining actual transmittance detection data and measurement data from the multi-layer filter membrane kit, the material, particle size, and shape adjustment direction of the interference smoke screen are determined. The computer module and PLC control the device's operating procedure, improving the device's automation.

The application discloses a pendulum Fourier transform spectrometer, a light beam entering a beam splitting prism is divided into two beams in the form of reflection and transmission, wherein the reflected beam splitting beam A is reflected by a mirror A again, penetrates the beam splitting prism and enters a detector; wherein the transmitted beam splitting beam B is reflected by a mirror B, is reflected by the beam splitting prism again, enters the detector and interferes with the light beam A, the mirror B is fixed to a movable end of a pendulum mechanism, the movable end of the pendulum mechanism reciprocates along the direction of approaching and leaving the beam splitting prism under the periodic pushing of a driver, and carries the mirror B which is always perpendicular to the direction of the light beam B. The driver is separated from the mirror B by arranging the pendulum mechanism, the stability of the mirror B is affected by the pendulum mechanism, and the pendulum mechanism only reciprocates around a rotating shaft under the traction of a heavy hammer on a rod / line, so that the structure and movement form of the pendulum mechanism are simpler than those of the driver, and therefore the reliability can be obviously improved.

The utility model discloses a VOCs (volatile organic compounds) emission flux infrared remote sensing monitoring system based on vertical wind field data, which comprises a mobile platform, the mobile platform is provided with an infrared shielding daily flux system, and the infrared shielding daily flux system is used for measuring an intermediate infrared absorption spectrum of the concentration of a volatile organic compound column. The infrared sun-masked flux system comprises a sun tracker and a mid-infrared Fourier transform spectrometer arranged at a light outlet of the sun tracker, a movable air extraction type Fourier transform infrared spectrum system is further arranged on the movable platform and used for measuring the volume concentration of the volatile organic compounds, a gas pump extracts plume air into a long-optical-path absorption cell, and the long-optical-path absorption cell is used for absorbing the plume air; the long-optical-path absorption cell is used for reflecting infrared light emitted by the infrared light source for multiple times and sending the infrared light to the intermediate infrared spectrometer; the mid-infrared spectrometer monitors and analyzes the plume air components and obtains the volume concentration of the to-be-detected components; the vertical wind field measuring device is used for continuously measuring wind speed and wind direction and acquiring vertical wind field data; and the positioning device is used for acquiring latitude and longitude information.

The invention discloses a portable near-infrared nondestructive testing device and a portable near-infrared nondestructive testing method for kiwi fruit quality. The device comprises an optical detection unit, a signal processing and control unit, a man-machine interaction unit and the like, wherein the optical detection unit adopts an MEMS Fourier transform spectrometer and a special probe with an annular light shield. The method comprises the following steps: establishing a kiwi fruit quality quantitative model based on partial least square regression and characteristic wavelength screening in a laboratory; the device is used for collecting spectrums on site, and a built-in model is called to predict indexes such as soluble solids, dry matters and acidity in real time. According to the invention, lossless, rapid, multi-index and on-site detection of the internal quality of kiwi fruits is realized, and the system has the advantages of high precision, good portability, strong anti-interference capability and the like, and is suitable for various scenes such as orchards, packaging lines, supermarkets and the like.

The invention relates to a polarization-insensitive cascade digital Fourier transform spectrometer, which comprises a beam splitter used for dividing an input optical signal into a first optical signal and a second optical signal; the Mach-Zehnder interferometer comprises a first arm, a second arm and a plurality of optical switch units, the first arm is used for transmitting a first optical signal, and the second arm is used for transmitting a second optical signal; the plurality of optical switch units are sequentially cascaded on the first arm and the second arm, and the optical switch units on the first arm are in one-to-one correspondence with the optical switch units on the second arm; the waveguide structures of the first arm and the second arm are micron-sized integrated optical waveguide structures, and the micron-sized integrated optical waveguide structures have geometric symmetry in width and height; the beam combiner is used for combining the first optical signal transmitted by the first arm and the second optical signal transmitted by the second arm into an interference signal; and the detector is used for converting the interference signal into an electric signal and outputting the electric signal. According to the invention, high-resolution spectrum reconstruction can be realized.