title: High speed scanning of terahertz pulse by a rotary optical delay line.
abstract: We demonstrate high speed scanning of a time-domain terahertz pulse by a rotary optical delay line (RODL) incorporated into a photoconductive antenna based terahertz system. The delay line of RODL consists of six rotating convex reflective blades with a rotating speed controlled for a wide range of scan repetition rates. It can perform path length scans of 2.1 cm at a scanning speed of 8.4 m/s while maintaining linearity. The comparison of the terahertz temporal waveform and the frequency spectrum measured by using the RODL and a linear stage optical delay line confirms the linearity of the RODL up to 140 ps at high scan repetition rates of 400 scan/s. A high signal-to-noise ratio, up to a few thousand, can be obtained by averaging multiple terahertz pulses at a high scan speed.
authors.affiliation: Terahertz Wave Research Group, Korea Electrotechnology Research Institute, 1271-19, Sa-Dong, Ansan, Gyeonggi 426-170, Republic of Korea.
authors.forename: Geun-Ju
authors.initials: GJ
authors.lastname: Kim
authors.forename: Seok-Gy
authors.initials: SG
authors.lastname: Jeon
authors.forename: Jung-Il
authors.initials: JI
authors.lastname: Kim
authors.forename: Yun-Sik
authors.initials: YS
authors.lastname: Jin