High speed scanning of terahertz pulse by a rotary optical delay line.
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.
Kim
Geun-Ju
GJ
Terahertz Wave Research Group, Korea Electrotechnology Research Institute, 1271-19, Sa-Dong, Ansan, Gyeonggi 426-170, Republic of Korea.
Jeon
Seok-Gy
SG
Kim
Jung-Il
JI
Jin
Yun-Sik
YS