This proposal requests funds to permit Dr. Anthony E. Siegman, Department of Electrical Engineering, Stanford University, to pursue with Dr. Sang Soo Lee and Dr. Hong Jin Kong, Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), for a period of 24 months, a program of cooperative research to develop a novel picosecond-time-resolved photothermal detection method for making ultrafast lifetime measurements of charge carriers and other excited states on the surfaces of semiconductors and other materials. The proposed technique will combine the time resolution of picosecond or femtosecond optical pulses with the unusual advantages of photothermal detection as a sensitive, flexible, noncontacting technique applicable to a large variety of metals, semiconductors and insulators, crystalline or amorphous, with essentially no requirements on surface preparation. The experimental research will be carried out by Dr. Kong, with guidance from Drs. Siegman and Lee, using the experimental facilities available at Dr. Siegman's laboratory at Stanford University. In this research a photothermal detection apparatus will be assembled and used to make measurements on various physical systems. The photothermal detection technique, in contrast to nearly all other picosecond measurement techniques, is a completely noncontacting method which does not require any special surface characteristics, polishing, or other special preparation. The collaborators are highly respected scientists with outstanding credentials in the field of the research. This project is relevant to the objectives of the U.S.-Korea Cooperative Science Program which seeks to increase the level of cooperation between U.S. and Korean scientists and engineers through the exchange of scientific information, ideas, skills, and techniques and through collaboration on problems of mutual benefit.
