ABSTRACT
Two methods are commonly used for broadband terahertz (THz) pulse generation: (1) transient photocurrent excitations in a biased photoconductive (PC) antenna and (2) optical rectication (OR) in a nonlinear crystal, both utilizing femtosecond lasers. While technological advances of the relatively unexplored spectral band are still in progress, the THz radiation sources have been used for a wide range of applications such as cancer diagnosis, identication of chemical and biological agents, security imaging, and noncontact inspection of packaged goods among many others (Lee 2009; Zhang and Xu 2009). Employing broadband THz pulses and time-resolved THz detection techniques, THz timedomain spectroscopy has become a standard method to obtain complex optical constants of matter in the THz region without imposing on Kramers-Kronig analysis.
