A Polarization-Resolved Study of Nanopatterned Photoconductive Antenna for Enhanced Terahertz Emission

Terahertz (THz) frequencies, despite having the potential for several important applications, have been relatively underexplored in the past owing to the unavailability of proper sources and detectors. The scenario has been changing over the past few decades due to the advent of convenient THz sources and detectors. THz photoconductive antennas (PCA), due to their attractive features, such as cost effectiveness and room temperature operation, are playing a key role in current and future research prospect in the field of THz spectroscopy, both as sources and detectors. Complex PCA designs have been proposed and studied to boost the THz emission efficiencies. Elucidating the underlying physics in such devices requires a thorough investigation of a few physical parameters. This requires the integration of several experimental techniques under identical conditions. In this paper, we show such a study, including a parametric variation of pump polarization, conducted on a PCA with a nanopatterned active region, which boosts the emitted THz radiation. Through the set of measurements, we unravel the subtle interplay of the various physical processes responsible for the emission of THz radiation from the device.