Measurement Techniques for Nonlinear Absorbing Materials: Femtosecond to Nanosecond Characterization()

Measurement Techniques for Nonlinear Absorbing Materials: Femtosecond to Nanosecond Characterization

Abstract：This talk focuses on the linear and nonlinear optical characterization techniques that are generally used across the femtosecond to nanosecond time regimes.Starting from linear characterization and then using the two most common nonlinear techniques, Z-scan and Pump and Probe, discussions and advice is given to collect and to utilize the results to yield the best possible experimental results.  To extract small nonlinearities, a dual-arm Z-scan setup is introduced and its results are compared to, and shown to be superior,to the normal Z-scan for extracting small nonlinearities.  Acquiring a full spectrum on just one molecule or nonlinear material can be very time consuming. This is due to the time it takes to re-align and re-calibrate the Z-scan setup at each wavelength when using an optical parametric generator (OPG) as a light source.  We have created a white-light continuum (WLC) spectrum generator using a long krypton gas cell. To modify this setup for increased energy output, we have added a weak seed pulse which results in a significant enhancement of output energy. 

Speaker：Dr. Scott Webster, University of Central Florida, Senior Research Scientist, Ph.D. from Wake Forest University

Scott Webster, Ph.D. received his doctorate in physics from Wake Forest University in 2003 investigating the “Optical Characterization of Nanostructured Materials”.  From 2004 to present, he has worked at CREOL, the College of Optics and Photonics at the University of Central Florida as a Senior Research Scientist.  He has published 62 refereed journal publications, 81 refereed conference proceedings and extended abstracts, presented 37 talks, lectures, and colloquia, has contributed to more than 90 other presentations, and has more than 1600 citations.  As of 2015, he has an h-index of 25. 

For roughly the last 10 years he has multitasked multiple programs in the linear and nonlinear characterization of organics, semiconductors, gasses, and plasmonic nanostructures in the femtosecond to nanosecond time regime and from the ultraviolet to the infrared spectral regime.  His specialty has been the linear and nonlinear characterization of Polymethine and Polymethine-like molecules for nonlinear absorption applications such as optical limiting.

报告时间：2015年6月16日，下午2点-4点

报告地点：南校区报告厅（研究生教学楼101阶梯） 

主办单位：研究生院、光电工程学院