Time-domain terahertz spectroscopy based on asynchronous optical sampling with femtosecond semiconductor disk laser

A terahertz time-domain spectroscopy (THz-TDS) system using an optically pumped semiconductor disk laser and high-speed asynchronous optical sampling is reported. The combination of these techniques holds considerable promise towards a compact and low-cost implementation of THz-TDS. The spectrometer offers a 333 ps time delay window scanned at 10 kHz and delivers more than 1.2 THz spectral coverage at a data acquisition time of one minute. As a proof-of-principle experiment, a 0.8 THz resonance of a frequency-selective surface structure was measured.