Title:  "Recent Advances of Infrared Semiconductor Laser based Chemical Sensing Technologies" 

Speaker: Frank K. Tittel

Time:  2:00 Pm  June 30th, 2008

Location: Room 212, Centre for Optical and Electromagnetic Research, East Building No.5, Zijingang Campus, Zhejiang University.

Abstract of the seminar:
 Recent advances in the development of infrared spectroscopic sources based on the use of both diode lasers and quantum cascade lasers (QCLs) for the detection, quantification and monitoring of both small and large molecular gas species with resolved and unresolved spectroscopic features respectively will be described. Applications include the monitoring of single and multiple gas species for applications in such diverse fields as in environmental monitoring, industrial process control, medical diagnostics and homeland security [1]. The architecture and performance of several sensitive, selective and real-time gas sensors based on infrared semiconductor lasers will be described. To date we have detected 16 gases (CH4, H2S, N2O, CO2, CO, NO, H2O, SO2, NH3, C2H2, OCS, C2H4, H2CO, C2H5OH, C2HF5 and CH3COCH3) at the ppm to ppt level [1,2].  High sensitivity requires sensitivity enhancement schemes such as a multipass gas absorption cell, cavity absorption enhancement, or photoacoustic spectroscopy. These methods can measure absorption coefficients as low as 10-9 cm-1 for field deployable gas sensors. A novel technique called Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS), which was first reported in 2002 will be emphasized.. QEPAS allows a breakthrough in size, weight, robustness and cost as well as wireless sensor network nodes for laser-based chemical sensing applications.

Biography of the speaker:

• Education:  B.A. (Physics), Oxford, England, 1955;  M.A. (Physics), Oxford, England, 1959;     Ph.D. (Physics), Oxford, England, 1959

• Professional Experience:

1. J.S. Abercrombie Professor, Rice University, 1989-present
2. Chair, Rice Quantum Institute, 1996-2000
3. Chair, Electrical & Computer Engineering Dept., Rice University, 1992-1995
4. Professor in Electrical Engineering, Rice University, 1973-1989
5. Associate Professor in Electrical Engineering, Rice University, 1967-73
6. Research Physicist, G.E. R&D Center, Schenectady, NY, 1959-65

• Honors: 

1. NASA-ASEE Faculty Fellowship, Goddard Space Flight Center, 1968-69
2. U.S. Senior Humboldt Awardee, Max Planck Institute: Göttingen, 1973-74; Munich, 1981
3. National Academy of Science Exchange Fellow, 1970, 1978, 1979
4. President, Optical Society of America, Gulf Coast Section, 1973
5. Visiting Professor, University of Aix-Marseille, 1990
6. Editor-in-Chief, Journ. Sel. Topics in Quantum Electronics, 1996-1998
7. Associate Editor, IEEE Journal of Quantum Electronics, 1992-present
8. Associate Editor, Applied Physics B, 1993-Present
9. Doctor of Science (HC), JATE University, Szeged, Hungary, 1993

• Memberships:  IEEE (Fellow), American Physical Society (Fellow), Optical Society of America (Fellow), SPIE (member)

• Current research interests include various aspects of quantum electronics, in particular laser spectroscopy, laser development, and laser applications in environmental monitoring, industrial chemical process control and breath analysis for medical diagnostics.

• Near collaborator to the Nobel Prize winner in Chemistry R. F. Curl.