Coherent CdTe terahertz source for high-resolutional imaging

Coherent terahertz generation is achieved in CdTe crystal at room temperature under the collinear difference frequency generation mechanism. This coherent terahertz source is pumped by the ns pulsed Nd:YAG Laser (1064 nm) and the tunable optical parametric oscillation (OPO 1050-1080 nm ) with the terahertz wave range 107.4 -381.9 μm and peak power of ~ 0.5 W. The emitted THz wave is continously tuned from 109.6 μm to 373.7 μm when the signal wavelength from OPO is changed from 1067.6 nm to 1074.9 nm. When the OPO signal wavelength is tuned from 1054.0 - 1061.6 nm, a terahertz wavelength region (107.4 - 381.9 μm) is achieved in the experiment. Compare with other terahertz sources like GaSe THz sourec or terahertz parametric generation source, this terahertz source is extreamly suited for the high-resolutional THz imaging application due to the simple way of the THz wavelength tunability.