基于腔衰荡的多谱线光谱分析

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关键词：腔衰荡光谱；多谱线光谱分析；痕量气体测量；压强展宽系数

中图分类号：0433.1 文献标志码：A doi：10.37188/CO.2024-0207 CSTR：32171.14.CO.2024-0207

Abstract： Laser absorption spectroscopy （LAS） has been widely applied in atmospheric monitoring， industrial production，medical diagnostics，andother fieldsdue to itshighsensitivity，rapid response，andreal-time online detection capabilities. However， spectral overlap interference remains a major challenge in LAS. In this study，a multispectral line spectral analysis approach based on cavity ring-down spectroscopy （CRDS） is proposed. A CRDS gas detection system was developed using a custom-designed cage-type Fabry-Perot cavity， and seven acetylene （C2H2） ）absorption lines in the range of 6452cm-1 to 6453cm-1 were selected for investigation. Experimental results demonstrate that the system is capable of accurately measuring and filling the multi-line absorption spectra of C2H2 with a minimum detection limit of 3.517×10-8cm-1 ， corresponding to a minimum detection volume fraction of 4.37×10-6 . Additionally， the intracavity pressure was precisely measured using a calibrated high-precision vacuum gauge. By analyzing the pressre-broadening effects observed in the absorption spectra， we calculated the pressure-broadening coeficients for three absorption lines， achieving a relative deviation below O.04.This study provides a novel method for multispectral line spectral analysis in LAS， improving measurement accuracy and broadening its applicability.

Key words： cavity ring-down spectroscopy; multispectral line spectral analysis; trace gas measurement; pressure-broadening parameter

1引言

激光吸收光谱技术（laserabsorptionspectro-scopy，LAS）基于光与气体分子的相互作用，具有高灵敏度、快速响应、多组分多参数实时在线检测等独特优势[1-3]，在大气环境分析、工业生产、医疗诊断等领域展现出了重要的应用价值4。（剩余12879字）