| 报告题目 | Trace species sensing by infrared laser spectroscopy |
| 报告人 | Prof. Markus W. Sigrist |
| 报告人单位 | ETH Zürich, Institute for Quantum Electronics, Switzerland |
| 报告时间 | 2016-03-28 |
| 报告地点 | 中国科学技术大学西区科技实验楼东楼1617会议室 |
| 主办单位 | 合肥微尺度物质科学国家实验室、中国科学技术大学物理系 |
| 报告介绍 | Abstract：
Chemical sensing and analyses of gas samples by laser spectroscopic methods are attractive owing to the high sensitivity and specificity, large dynamic range, multi-component capability, and lack of pretreatment or preconcentration procedures. The availability of broadly tunable mid-infrared sources like external cavity quantum cascade lasers (EC-QCLs), interband cascade lasers (ICLs), difference frequency generation (DFG), optical parametric oscillators (OPOs), recent developments of diode-pumped lead salt semiconductor lasers, of supercontinuum sources or of frequency combs have eased the implementation of laser-based sensing devices.
Sensitive techniques for molecular absorption measurements include multipass absorption, various configurations of cavity-enhanced techniques such as cavity ringdown (CRD), or of photoacoustic spectroscopy (PAS). The application requirements finally determine the optimum selection of laser source and detection scheme.
In this talk I shall discuss the basic principles, present various experimental setups and illustrate the performance of selected systems for chemical trace species sensing. Examples include the fast analysis of C1-C4 alkanes at sub-ppm concentrations, measurements on short-lived species like nitrous acid (HONO) or a true analysis of a multi-component gas mixture like surgical smoke in a medical application. Finally, results will be presented on non-invasive glucose sensing through human skin. |
