使用基于石英增强光声光谱的传感器和单模光纤耦合量子级联激光激发，实现 SF6 的万亿分之一级检测。

Part-per-trillion level SF6 detection using a quartz enhanced photoacoustic spectroscopy-based sensor with single-mode fiber-coupled quantum cascade laser excitation.

机构信息

Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN UOS BARI, Bari, Italy.

出版信息

Opt Lett. 2012 Nov 1;37(21):4461-3. doi: 10.1364/OL.37.004461.

DOI:10.1364/OL.37.004461

Abstract

A sensitive spectroscopic sensor based on a hollow-core fiber-coupled quantum cascade laser (QCL) emitting at 10.54 μm and quartz enhanced photoacoustic spectroscopy (QEPAS) technique is reported. The design and realization of mid-IR fiber and coupler optics has ensured single-mode QCL beam delivery to the QEPAS sensor. The collimation optics was designed to produce a laser beam of significantly reduced beam size and waist so as to prevent illumination of the quartz tuning fork and microresonator tubes. SF(6) was selected as the target gas. A minimum detection sensitivity of 50 parts per trillion in 1 s was achieved with a QCL power of 18 mW, corresponding to a normalized noise-equivalent absorption of 2.7×10(-10) W·cm(-1)/Hz(1/2).

摘要

一种基于中空光纤耦合量子级联激光器（QCL）在 10.54μm 处发射的灵敏光谱传感器和石英增强光声光谱（QEPAS）技术的报告。中红外光纤和耦合器光学的设计和实现确保了单模 QCL 光束传输到 QEPAS 传感器。准直光学器件的设计产生了显著减小的光束尺寸和腰束，以防止石英音叉和微谐振器管的照明。SF₆被选为目标气体。在 18mW 的 QCL 功率下，实现了 50 个部分每万亿在 1 秒的最小检测灵敏度，对应归一化噪声等效吸收为 2.7×10^-10W·cm^-1/Hz^1/2。