讲座题目：Sensing with IR laser spectroscopy
报 告 人：Prof. Markus W. Sigrist
ETH Zürich, Institute for Quantum Electronics, CH-8093 Zürich, Switzerland
After a brief introduction to ETH Zurich, I shall discuss IR laser spectroscopic applications to chemical sensing and analyses. Such methods offer high sensitivity and specificity, large dynamic range, multi-component capability, and easy use without sample preparation.
The availability of broadly tunable mid-infrared laser 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 (mid-IR VECSELs), of supercontinuum sources or of frequency combs have eased the implementation of laser-based sensing devices. Detection schemes rely on sensitive absorption measurements by multipass absorption, cavity-enhanced techniques or on photoacoustic detection.
In this talk I shall discuss the basic principles, present various experimental setups and illustrate the performance of selected systems for trace species sensing. Examples include atmospheric trace gas monitoring emitted by road traffic with a mobile CO2 laser-based system, the fast analysis of C1-C4 alkanes at sub-ppm concentrations with a new type of VECSEL (of interest for the petrochemical industry) as well as measurements on short-lived species like the detection of the key atmospheric compound nitrous acid (HONO) with a QCL-photoacoustic system.
Besides environmental, medical applications are also of great interest today. We demonstrate the analytical capabilities of IR laser spectroscopy with a study on in situ surgical smoke using a broadly tunable DFG laser source. Finally, I shall present results on our most recent study: a new type of QCL-based photoacoustic sensor for non-invasive in vivo measurements of glucose directly through human skin.
Markus W. Sigrist heads the group "Laser Spectroscopy and Sensing" at the Institute for Quantum Electronics of ETH Zurich. In 1996 he was awarded the title of Professor for Experimental Physics. His current research focuses on the development, implementation and application of tunable mid-infrared laser sources and sensitive detection schemes for laser-spectroscopic analyses ranging from environmental, industrial and agricultural applications to medical diagnostics.
He studied physics at ETH Zurich. He then performed his PhD thesis in the Laboratory for Solid State Physics with Prof. F.K. Kneubühl and received his PhD degree from ETH in 1977. From 1978 to 1980 he was a postdoctoral fellow at the University of California at Berkeley (USA). Back at ETH he completed his habilitation received the docent degree (Privatdozent) in 1985. After a sabbatical year at Rice University in Houston, Texas (USA) in 1990, he was awarded the title of Adjunct Professor at Rice in 1994. In 2003 he was an invited professor at the Université du Littoral in Dunkerque, France. In 2015, he was awarded the visiting professorship of Chinese Academy of Sciences under PIFI program.
Prof. Markus Sigrist is the author and coauthor of over 200 publications in refereed journals as well as tens of book chapters, encyclopedia series, and books. He coauthored the well-known German textbook entitled „Laser“ with F.K. Kneubühl (7th ed., 2008), and edited the book entitled "Air Monitoring by Spectroscopic Techniques“ (Wiley, New York, 1995).
Prof. Markus Sigrist is a fellow of the Optical Society of America (OSA) since 1999 and a member of various national and international societies and committees. He is a board member of the Swiss Society of Optics and Microscopy (SSOM) since 1993. He is also a member of the editorial board of various scientific journals and a regular member of international conference committees.