Investigation on Bias Electric Fields Produced by Improved Photoconductive Antenna Structures

The terahertz (THz) band is generally referred to as the electromagnetic spectrum between 0.1 and 10 THz. Because of its attractive features such as chemical specificity, penetration capability, non-ionisation, and wide bandwidth, this least explored frequency band has become the focus of many researchers. Currently the photoconductive antenna is widely used to generate THz waves. However, the THz power generated from photoconductive antenna is still very low. This prohibits many practical applications such as single-shot THz imaging. Thus it is of general interest and importance to improve the performance of the photoconductive antennas. Recently, an improved structure has been shown to generate higher THz power than the conventional structure and this paper is to conduct further investigation in this area.