Development of a terahertz time-domain spectroscopy setup based on a 1550 nm femtosecond fiber laser

We report on the design, construction, and development of a 1550 nm femtosecond fiber laser-based terahertz time-domain spectroscopy (THz-TDS) setup. A p-InAs (100) bare semiconductor wafer was used as the emitter and a low-temperature-grown(LTG)-InGaAs bow tie photoconductive antenna (PCA) was used as detector. The measured THz emission from p-InAs has peak-to-peak amplitude of 116 pA, pulse width of 2 ps, bandwidth of 2 THz, and signal-to-noise ratio of 3 orders of magnitude.