title: High-speed terahertz time-domain spectroscopy based on electronically controlled optical sampling.
abstract: We demonstrate high-speed terahertz (THz) time-domain spectroscopy based on electronically controlled optical sampling (ECOPS). The ECOPS system utilizes two synchronized Ti:sapphire femtosecond lasers with a 100 MHz repetition frequency. The time delay between the two laser pulses is demonstrated to be rapidly swept at a scan rate of 1 kHz on a time delay window of 77 ps by using an external offset voltage applied to a locking electronics. It is shown that a THz pulse can be exactly measured by ECOPS, as is done by asynchronous optical sampling (ASOPS), and the measurement time is shortened by a factor of 50 by using ECOPS compared with ASOPS in the case of employing 100 MHz repetition-rate lasers.
authors.affiliation: Center for Safety Measurement, Korea Research Institute of Standards and Science, Daejeon 305-340, Korea.
authors.forename: Youngchan
authors.initials: Y
authors.lastname: Kim
authors.forename: Dae-Su
authors.initials: DS
authors.lastname: Yee