THz TDS system with 105 dB dynamic range based on transition metal doped InGaAs

A THz time-domain spectroscopy (TDS) system is presented, which uses photoconductive antennas made of iron and rhodium doped InGaAs. Due to the unique combination of ultrashort lifetime and high mobility as well as high resistivity, the transition metal doped InGaAs surpasses the performance of state-of-the-art photoconductors when applied as THz antennas: The presented THz TDS system features a spectral bandwidth of 6.5 THz and a dynamic range of up to 105 dB.