Method and device for detecting multi-component gas through semiconductor laser modulated spectrum

Abstract

The invention relates to a method and a device for detecting multi-component gas through a semiconductor laser modulated spectrum. A temperature controller and an adjustable constant flow source are adopted for driving a semiconductor laser, a scanning signal source generates a scanning control signal and injects the scanning control signal into the temperature controller to realize continuous change of temperature, so as to drive the semiconductor laser to output laser with continuous wavelength change, wherein the output laser is divided into two paths, one path of laser and the other path of laser passing through a gas absorption cell are received by a balanced detector commonly, and the scanning signal source synchronously triggers a data acquisition card to acquire a signal output by the balanced detector and input the signal to a computer for processing, so as to obtain the multi-component detection result. According to the method and the device for detecting the multi-component gas through the semiconductor laser modulated spectrum, the range of the continuous output wavelength of the semiconductor laser is expanded and the defects of narrow range of the continuous output wavelength and single detected gas type of a current driving laser are overcome, therefore, the method and the device for detecting multiple gases simultaneously by the single semiconductor laser are provided; the multi-component gas detection cost is reduced, the detection efficiency and the detection reliability are improved, and the method and the device are used for the monitoring and detecting industry of various gases.

Description

Technical field: [0001] The invention belongs to the technical field of optics and spectroscopy, and mainly relates to a method and structure for realizing modulation spectrum of a semiconductor laser, in particular to a method and device for detecting multi-component gas of a modulation spectrum of a semiconductor laser. It is used in the fields of gas detection and gas absorption spectrum analysis. Background technique: [0002] Gas detection usually uses infrared absorption spectroscopy. Infrared absorption spectroscopy uses infrared light as the detection light source. The semiconductor laser has the characteristics of small size, good monochromaticity and continuously adjustable wavelength, making it a commonly used light source device in infrared absorption spectroscopy. [0003] Semiconductor lasers are used for gas detection using wavelength modulation spectroscopy. Wavelength modulation refers to the use of continuous changes in current to drive semiconductor las...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the problem that the semiconductor laser in the prior art can only be used for one kind of gas detection, and proposes a temperature-modulated spectral scanning, which has a wide scanning spectral range, low cost, high reliability, and can be used with a single Semiconductor laser modulation spectrum multi-component gas detection method and device for simultaneous detection of multiple gases by branching semiconductor lasers

The invention utilizes the continuous change of temperature to drive the laser with continuously changing output wavelength of the semiconductor laser, which greatly expands the range of the continuous output wavelength of the semiconductor laser, and solves the problem that the output wavelength range of the current continuous drive semiconductor laser is narrow, and one laser can only be used for one kind of gas detection. Defects, providing a semiconductor laser spectrum gas detection device with a wide spectral scanning range and a single semiconductor laser for simultaneous detection of multiple gases

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