Femtosecond pulses from ultrafast lasers can be used to generate single-cycle, terahertz-bandwidth waveforms in both electromagnetics and acoustics. This talk will describe how we generate such pulses, and apply them to problems in imaging. THz electromagnetic pulses can be generated with controllable waveform and bandwidth using nonlinear optical methods. These pulses can then be used in a technique called "time-reversal imaging" to reconstruct images of three-dimensional objects (including objects embedded in optically opaque media) in a similar fashion, we can generate picosecond-duration acoustic pulses (coherent acoustic phonons). By applying the time-reversal method, we can use these pulses to image structures on silicon with nanoscale resolution. We describe how images of subsurface nanostructure will be enabled by this technique.
Theodore B. Norris is a Professor in the EECS Department and Director of the Center for Ultrafast Optical Science at the University of Michigan. He received his B.A. in Physics (with Highest Honors) from Oberlin College in 1982, and his PhD in Physics from the University of Rochester in 1989. His postdoctoral research was performed at Thomson-CSF in France 1989-1990. His research interests include application of femtosecond optical techniques to the physics of semiconductor nanostructures, in developing new ultrafast optical and optoelectronic measurement techniques, THz generation and measurement, plasmonics in nanostructures, nanoacoustics, and novel methods for biological imaging and in vivo sensing. He is a member of IEEE and, and is a Fellow of the Optical Society of America and the American Physical Society.
Host: Prof. Seamus Curran
634 S&R 1 - 4PM