Optical cavity ringdown spectrometer system

Abstract

The invention provides an optical cavity ringdown spectrometer system and aims at improving the sensitivity of spectrum measurement. The system comprises a continuous laser, a first light beam splitter coupled to the continuous laser, an acousto-optic modulator and a wavemeter coupled to the first light beam splitter, a second light beam splitter coupled to the acousto-optic modulator, a third light beam splitter coupled to the second light beam splitter, a ringdown cavity coupled to the third light beam splitter, and a computer coupled to the wavemeter and the continuous laser; and first andsecond reflectors are arranged in the inner two ends of the ringdown cavity respectively, and a piezoelectric ceramic tube is arranged in the output end of the ringdown cavity and is connected with the computer via a photoelectric conversion device. Thus, high-precision continuous wavelength scanning can be realized, the spectrum measuring precision can reach the 10-<4>cm<-1> level, and compared with the prior art, the sensitivity of spectrum measurement is improved substantially.

Description

technical field [0001] The application belongs to the field of scientific research equipment manufacturing, in particular to an optical cavity ring-down spectrometer system. Background technique [0002] At present, there are many methods for gas concentration detection, including acoustic sensors, sensors based on traditional absorption spectroscopy, Raman spectroscopy sensors, mass spectrometry sensors, nuclear magnetic resonance sensors, and electrical sensors. Although these existing sensors play an important role in the detection of gases, they generally have the characteristics of low sensitivity and complicated operation, so their application in the detection of trace gas concentrations has obvious limitations. [0003] Cavity Ringdown Spectroscopy (CRDS) technology is an absorption spectroscopy technique that achieves high-sensitivity spectral detection by measuring the light loss caused by sample scattering and absorption in an optical cavity. In addition to the an...

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Problems solved by technology

[0004] Most of the early intracavity ring-down spectroscopy used pulsed laser as the light source, but due to the large laser linewidth, multiple longitudinal modes will be coupled with the optical cavity at the same time during the laser ring-down process, so the ring-down curve of the laser becomes As a result of superposition of multiple exponential decays, there is a large deviation (about 1% level) in the sample gas absorption coefficient obtained by fitting at this time, thus reducing the detection sensitivity

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