12 results about "Modulation spectroscopy" patented technology

The low-noise atom modulation spectrum detection system comprises a signal generator, sine wave signals generated by the signal generator are divided into two paths, one path is output to a laser device, and laser with modulation information is modulated in a current control mode; and the other path provides a reference signal for demodulation of the lock-in amplifier, the output laser is divided into pump light and probe light to ensure generation of saturated fluorescence in the rubidium atom steam chamber, then a low-noise silicon photoelectric detector is used for detecting a saturated fluorescence signal, and the lock-in amplifier demodulates and outputs the modulated saturated fluorescence signal. And meanwhile, a detection path of the saturated absorption spectrum is reserved, so that comparison with a modulated saturated fluorescence spectrum signal is facilitated. According to the invention, the requirement on the size of the atom steam chamber is obviously reduced, and the method is suitable for the application scenes of the Suppler spectrum, such as high-sensitivity, low-noise, anti-interference and miniaturized laser frequency stabilization and atom hyperfine structure detection.

A flow meter is positioned in an Microfluidic Modulation Spectroscopy system at the output of the Y junction of a flow cell. The MMS system instantaneously measures the flow rate through the flow cell and adjusts parameters such as fluid backing pressure, valve open time, and dwell time before data collection. This allows an opportunity to optimize the system performance and minimize the fluid usage in real time. The flow sensor is capable of measuring fluid flow in the range of 0-100 microliter per second. The incorporation of the flow meter at the output of the Y junction immediately following measurement of the sample and reference fluids allows for real-time adjustments of operating parameters. The capability of the system to adjust operating parameters and make corrections in real time based on the measurements by the flow meter allows the instrument to automatically measure arrays of samples on a well plate.

The invention discloses a high-resolution extraction method of an electro-optical modulation spectrum, belongs to the technical field of photoelectrons, and aims to realize high-resolution extraction of the electro-optical modulation spectrum. According to the method, a frequency shift heterodyne structure is established, heterodyne beat frequency is carried out on an electro-optical modulation spectrum to be detected and a frequency shift optical signal, and an optical domain spectrum is converted into a radio frequency domain and is received and detected by an electric spectrometer; the optical frequency shift module performs up-shift on the optical carrier, the frequency shift amount is fs, and the frequency shift amount is equal to the output frequency of the driving source. By analyzing the distribution characteristics of spectral lines in the measured electric spectrum, a spectrum-electric spectrum frequency mapping relation is established, and the frequency information of the electro-optical modulation spectrum to be measured can be solved; through back-end calibration processing, spectrum-electric spectrum power mapping is in a linear relation, and power information of the electro-optical modulation spectrum to be measured can be recovered. In conclusion, through inverse solution of the spectrum-electric spectrum mapping relation, the electro-optical modulation spectrum to be measured can be extracted from the electric spectrum, and benefited from the sub-Hz-level resolution of the electric spectrometer, the extraction method has the characteristic of high resolution.

A method of determining an optical spectrum for a sample substance includes splitting a source beam into a reference beam and a sample beam, periodically modulating the intensity of the beams out of phase of each other, directing the reference beam through a reference substance and the sample beam through the sample substance. The beams are then recombined, and a single detector detects the intensity difference at the modulation frequency to determine the spectrum of the sample substance.

This application provides a gas detection system and method based on near-infrared wavelength modulation and mid-infrared pulsed laser synergy, relating to the fields of spectroscopic gas detection and industrial flue gas monitoring. In industrial sites such as biomass power plants, hazardous waste incineration plants, and aluminum smelters, the flue gas generated in their flues has complex compositions. Traditional chemical detection methods are insufficient to meet real-time requirements, while other optical detection methods, such as Fourier transform infrared spectroscopy and ultraviolet differential spectroscopy, suffer from high costs and difficulty in avoiding water vapor interference. To address this, a system and method for detecting the concentration of gaseous pollutants in industrial flue gas based on near-infrared wavelength modulation and mid-infrared pulsed laser synergy is proposed. This system combines near-infrared wavelength modulation spectroscopy with mid-infrared pulsed direct absorption spectroscopy, employing multiple near-infrared tunable continuous lasers and mid-infrared tunable pulsed lasers. It utilizes time-division multiplexing and polling modes, combined with a common optical path design, to achieve real-time online monitoring of the concentration of various gaseous pollutants, ultimately significantly reducing the overall system cost.

This invention discloses a high-precision gas parameter measurement system and method based on the harmonic reconstruction principle, belonging to the field of data processing technology. The method includes the following steps: S1, processing the modulated transmittance signal to obtain harmonic curves from order 0 to k0; S2, obtaining the variation curves of each order harmonic with respect to the laser frequency based on the laser frequency variation signal and the harmonic curves from order 0 to k0; S3, determining the molecular absorption spectrum based on the variation curves of each order harmonic with respect to the laser frequency; S4, analyzing the molecular absorption spectrum to determine the physical parameters of the gas being measured. This invention retains the core advantages of wavelength modulation spectroscopy, such as high signal-to-noise ratio, strong anti-interference capability, and high measurement accuracy, while providing a new measurement method for high-precision calibration of spectral physical parameters, high-precision measurement of gas parameters under weak absorption conditions, and gas monitoring in complex industrial environments, effectively expanding the measurement efficiency and application scope of this technology.

The present invention discloses a self-calibration measurement system and method applicable to the detection of lunar surface polarization spectral characteristics, belonging to the field of optical detection, including: along the propagation direction of incident light, a first achromatic quarter-wave plate, a multi-stage wave plate, a second achromatic quarter-wave plate, a beam splitting prism and two Wollaston prisms are sequentially arranged. The present invention uses the second achromatic quarter-wave plate, the beam splitting prism and two Wollaston prisms to form a polarization phase shift unit. After the incident light passes through the first achromatic quarter-wave plate and the multi-stage wave plate, the polarization information is modulated in the spectral dimension. The polarization phase shift unit shifts the modulated spectral phase by 0°, 180°, 90° and 270° to form two pairs of complementary modulated spectra. After the multi-stage wave plate is rotated by 90°, a secondary measurement is performed. The present invention can use the modulated spectra of the two measurements to extract the phase delay amount of the multi-stage wave plate in real time, and can solve the problem of the phase delay amount offset of the multi-stage wave plate caused by the temperature control fluctuation of the measurement system due to the large temperature difference on the lunar surface.

A Microfluidic Modulation Spectroscopy (e.g. MMS) system enables measurement of a liquid analyte with a weak absorbance in a prescribed reference solution with a very high absorbance. The method includes alternatively flowing the liquid analyte and the prescribed reference solution through a fluid chamber in a liquid flow cell. The temperature of the analyte can be changed following a predetermined curve while spectral data is being collected. As the temperature of the analyte is increased, outgassing of trapped and dissolved air dissolved in the liquid analyte may be reduced, especially within the interrogation region of the flow cell, by application of a backpressure to the exit line of the flow cell. This is important for proteins, RNA, DNA, and other biomolecules because their structure and function are often temperature dependent. Further, some biological drugs need to be distributed globally and may encounter a range of ambient conditions in shipping.

A flow meter is positioned in an Microfluidic Modulation Spectroscopy system at the output of the Y junction of a flow cell. The MMS system instantaneously measures the flow rate through the flow cell and adjusts parameters such as fluid backing pressure, valve open time, and dwell time before data collection. This allows an opportunity to optimize the system performance and minimize the fluid usage in real time. The flow sensor is capable of measuring fluid flow in the range of 0-100 microliter per second. The incorporation of the flow meter at the output of the Y junction immediately following measurement of the sample and reference fluids allows for real-time adjustments of operating parameters. The capability of the system to adjust operating parameters and make corrections in real time based on the measurements by the flow meter allows the instrument to automatically measure arrays of samples on a well plate.

A Microfluidic Modulation Spectroscopy (e.g. MMS) system enables measurement of a liquid analyte with a weak absorbance in a prescribed reference solution with a very high absorbance. The method includes alternatively flowing the liquid analyte and the prescribed reference solution through a fluid chamber in a liquid flow cell. The temperature of the analyte can be changed following a predetermined curve while spectral data is being collected. As the temperature of the analyte is increased, outgassing of trapped and dissolved air dissolved in the liquid analyte may be reduced, especially within the interrogation region of the flow cell, by application of a backpressure to the exit line of the flow cell. This is important for proteins, RNA, DNA, and other biomolecules because their structure and function are often temperature dependent. Further, some biological drugs need to be distributed globally and may encounter a range of ambient conditions in shipping.

The invention discloses a water vapor column concentration laser telemetering system and method based on TDLAS-WMS. The system comprises an electronics control unit, a laser modulator, a near-infrared laser, a collimator, a dichroscope, a first reflector, a second reflector, an optical convergence telescope, a narrow-band filter, a detector, a ranging radar and a visible light laser. According to the invention, the TDLAS-WMS-2f / 1f technology is used, and high-precision and high-stability water vapor column concentration measurement is realized. The tunable semiconductor laser absorption spectrum is combined with the wavelength modulation spectrum technology, signal processing is carried out according to the ratio of second harmonics to first harmonics, and interference caused by light intensity fluctuation, atmospheric turbulence and non-absorption loss in the light path transmission process can be effectively eliminated.