David Crowley with Prof. Jie Shan

Thin Films for THz Generation

THz generation is a well known nonlinear effect that has been used in many spectroscopic methods. Most well known is time domain spectroscopy (THz TDS) which has the additional benefit of not only providing information on the amplitude changes, but also the phase change in the THz radiation as a result of traveling through a medium. THz radiation has been generated with the use of photoconductive antennas, black body sources, and optical rectification; to name a few. Optical rectification often uses crystals such as ZnTe in accord with a pulsed femtosecond laser to create the nonlinear effects which produce THz radiation. Thin films have also shown some success in showing this effect. Polymers however do not naturally align themselves in such a way that the molecules have a high order of and need to be polled or aligned with electric fields and then held in place to show a larger effect. Films necessary for THz generation will be created and then tested alongside the ZnTe crystals in order to understand their comparative efficiency in THz generation.