提升多次反射腔增强拉曼气体检测灵敏度

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Enhancing sensitivity of multi-pass cavity enhanced Raman gas detection

（1. State Key Laboratory of Quantum Optics and Quantum Optics Technologies and Devices， Institute ofLaser Spectroscopy，Shanxi University，Taiyuan O3OOo6，China; 2. Collaboratirve Innovation Center of Extreme Optics， Shanxi University， Taiyuan O3006，China） * Corresponding author，E-mail： zhaoyt@sxu. edu. cn

Abstract： To address the limited Raman scattering area，which diminishes signal strength and detection sensitivity，this study enhances the Raman signal intensity and detection sensitivity through optical path optimization. Experiments investigating various reflection modes within the cavity and colection system angles examined the effects of the incident light's polarization state and dual-path collection on the Raman scatering signal. Utilizing the optimized parameters，a multi-pass reflective cavity system was developed. Using the Raman spectra of oxygen and nitrogen in air as reference signals，results demonstrated that the signal intensity with P-polarized incident light was 1.3 times greater than that with S-polarized light. Implementation of a dual-ath collection system increased the total collected scatered light，thereby improving Raman scattering collection eficiency. The signal-to-noise ratio of the dual-channel collection system increased by1.5times for Channel A and1.7 times for Channel B，enabling the detection of carbon dioxide in air. Furthermore，the device exhibited a strong linear correlation between signal intensity and gas concentration，confirming its capability for quantitative analysis.

Key words： spectroscopy; Raman spectroscopy; gas detection; cavity-enhanced; near-confocal cavity

1引言

拉曼光谱技术因其非破坏性、高灵敏度、快速响应[1]及多组分分析能力等优点[2-3]，在多个领域得到了广泛应用[4-5]。（剩余11367字）