We discuss the design considerations of traveling-wave electrooptic terahertz sensors, wherein we analyze limitations in frequency response due to velocity-mismatch in the sensor crystal. In zincblende electrooptic materials, optical group velocities are found to be able to match the phase velocity of low frequency terahertz wave at specific optical center frequencies. We observed excellent velocity-matching in ZnTe crystals within the tuning range of Ti:sapphire lasers. Terahertz pulses as short as 200 fs (full-width-at-half-maximum) have been measured using the ultra-broad-band radiation generated via terahertz optical rectification.
展开▼
