Mixture component identification method based on terahertz absorption spectrum processing

Abstract

The invention provides a mixture component identification method based on terahertz absorption spectrum processing, and belongs to the field of optical measurement. The method comprises the following steps: detecting components of a mixture by a terahertz absorption spectrum; firstly, obtaining a terahertz absorption spectrum of a mixture sample, deducting environment noise and background noise, and removing the effects caused by water vapor absorption changing along with the temperature; obtaining the terahertz absorption spectrum for identification, transferring a terahertz absorption spectrum database, and sequentially judging, identifying and deducting the terahertz absorption spectra of kinds of samples by template matching and absorption peak comparison methods; and judging the deducted absorption spectrum data until all components of the mixture are detected. By combination of the terahertz absorption spectrum in an experiment environment with the terahertz absorption spectrum in a conventional environment, the mixture component identification method can be applied to terahertz absorption spectrum identification in the conventional environment; and a guarantee is provided for application of a terahertz absorption spectrum identification technology.

Description

technical field [0001] The invention belongs to the field of optical metrology, and mainly relates to a terahertz absorption spectrum processing method, in particular to a terahertz spectrum processing method applied to mixture component identification. Background technique [0002] Terahertz radiation usually refers to electromagnetic radiation with a frequency in the range of 0.1 to 10 terahertz (THz), which can penetrate most non-metallic and non-polar substances, but specific substances such as explosives, metals, and some drugs have significant effects on terahertz radiation. The terahertz absorption spectrum corresponding to the substance can be obtained by investigating these absorption phenomena. The terahertz absorption spectrum of different substances is different, and the corresponding material composition can be determined by analyzing and processing the absorption spectrum. [0003] The existing terahertz absorption spectrum processing methods often have certain...

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Problems solved by technology

[0003] The existing terahertz absorption spectrum processing methods often have certain errors in determining the composition of the measured sample, especially when the measured sample is a mixture, the measured terahertz absorption spectrum is the superposition of the absorption spectra of various components, and now Some processing methods can only detect one or part of the components, but cannot distinguish all the components one by one. Even due to the interference of the background environment, the signal-to-noise ratio of the absorption spectrum is very poor, resulting in the inability to identify any of the components.

During the terahertz absorption spectrum test, due to the unstable frequency of the terahertz light source or the low precision of the equipment, the frequency drift occurs in the position of the absorption peak in the measured absorption spectrum, resulting in the corresponding substance being unable to be detected

At the same time, if the measured object is in the air environment, the absorption spectrum of water vapor will be mixed into the terahertz absorption spectrum of the measured object, and the above-mentioned shortcomings of the existing processing methods will be more obvious, which greatly restricts the application of terahertz technology

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