Broadband-spectrum type photoacoustic spectrometric long-distance detection apparatus and method for trace substances

Abstract

The invention discloses a broadband-spectrum type photoacoustic spectrometric long-distance detection apparatus for trace substances, belonging to the field of spectrometric detection of trace substances. The apparatus comprises an excitation light source, a reflecting object, a concave mirror, a carbon nanotube composite photoacoustic energy transducer, a quartz tuning fork, a coupler, a fiber laser, a photoelectric detector and a data processing system, wherein the excitation light source and the reflecting object are located on a same light path; the concave mirror is arranged on the emergent path of the reflecting object; the carbon nanotube composite photoacoustic energy transducer is located at the focus of the concave mirror; the quartz tuning fork and the end surface of an optical fiber form Fabry-Perot cavity; the coupler is connected with the optical fiber; the fiber laser is connected with the coupler via the optical fiber; and the coupler is successively connected with the photoelectric detector and the data processing system via the optical fiber. The invention also discloses a broadband-spectrum type photoacoustic spectrometric long-distance detection method for trace substances and realizes long-distance detection of a plurality of trace substances.

Description

technical field [0001] The invention relates to the technical field of trace substance spectrum detection, in particular to a wide-spectrum photoacoustic spectrum trace substance long-distance detection device and method. Background technique [0002] The development of long-distance detection technology for trace substances is of great significance for long-distance detection of explosives, detection of toxic and harmful substances, and air quality monitoring. Laser infrared spectroscopy has the advantages of high spectral resolution, wide measurement range, and fast response speed, and has become a very important choice for the development of remote trace substance detection technology. Generally speaking, laser infrared spectroscopy mainly includes tunable diode laser absorption spectroscopy, laser photoacoustic spectroscopy, laser photothermal spectroscopy, and laser photothermal spectroscopy based on micro-cantilever beams. Among them, laser photoacoustic spectroscopy ...

AI Technical Summary

Problems solved by technology

However, the infrared absorption efficiency of the material of the quartz tuning fork itself is low, and the absorption spectrum range is narrow. When directly detecting the light intensity, there are disadvantages such as low light energy utilization rate and narrow spectrum absorption range, so its detection sensitivity is low, and It can only complete the detection of one or several specific substances, and cannot realize the detection of multiple substances in an ultra-wide spectral range

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