Gas detection device and method based on optical cavity ring-down spectroscopy technology

Abstract

The invention discloses a gas detection device and method based on an optical cavity ring-down spectroscopy technology, and relates to the technical field of gas detection. The device comprises a pulse laser source, an optical isolator, an optical fiber circulator, a photoelectric detector, a data acquisition and processing control unit and a high-reflection ring-down cavity, the input end of the pulse laser source is electrically connected with the output end of the data acquisition and processing control unit, and the output end of the pulse laser source is coupled to the input end of the optical isolator through a transmission optical fiber. According to the method, the pulse of the pulse laser and the data acquisition time sequence are controlled, pulse ring-down curve data are repeatedly acquired for multiple times, the data resolution is improved through spatial domain data interpolation, the signal-to-noise ratio of the ring-down curve is improved through time domain data accumulation, and the accuracy of enveloping datum point data of the ring-down curve is improved through data segmentation integral reconstruction, the problems that an existing gas detection technical scheme is high in cost, large in debugging difficulty, much in environmental interference and the like are solved.

Description

technical field [0001] The invention belongs to the technical field of gas detection, and in particular relates to a gas detection device and method based on optical cavity ring-down spectroscopy technology. Background technique [0002] Cavity Ring Down Spectroscopy (CRDS for short) uses the interaction mechanism between laser and gas molecules for gas detection. The pulsed laser is used as the light source, and the ring-down cavity is formed by a high-reflectivity cavity mirror. The laser pulse is reflected back and forth in the high-reflection ring-down cavity to form a ring-down optical path. [0003] According to the Lambert-Beer law, the intensity I(t) of the light pulse returned by the circulator is determined as an exponential function varying with time. Among them, R is the reflectivity of the high mirror (R>99.99%), c is the speed of light, L is the distance between the two mirrors, and α is the absorption coefficient of the gas to be measured in the ring-down ...

AI Technical Summary

Problems solved by technology

[0012] The purpose of the present invention is to provide a simple and effective device and method, which can detect gas by means of optical cavity ring-down spectroscopy, has simple structure, strong practicability, good maintainability, high accuracy, and can significantly reduce the measurement caused by environmental interference. Inaccuracy can significantly improve the engineering application of optical cavity ring-down spectroscopy technology in the field of gas detection, and solve the problems of high cost, difficult debugging and environmental interference of existing gas detection technology solutions

Images