Terahertz Time-Domain Spectroscopy setup based on photoconductive antennas

Despite the technical difficulties in developing efficient and compact sources and detectors for Terahertz (THz) radiation, this region of the electromagnetic spectrum is attracting an ever-increasing interest, due to its peculiar and high-potential applications in several fields, such as wideband communications, medicine, biology, non-destructive testing, security and defense. Within such contexts, the most widespread approach aiming to deal with THz pulses is based on the THz Time-Domain Spectroscopy (THz-TDS) system. In this work, we present our experimental results obtained by means of a THz-TDS set-up based on photoconductive antennas for both the generation and detection stage. It is composed by i) a mode-locked Ti:Sapphire femtosecond laser (Mai-Tai SP - Spectra Physics, (800±20 nm, 120 fs, 84 MHz); ii) two LT-GaAs photoconductive antennas, acting as THz emitter and detector; iii) an optical delay line.