Compact high-repetition-rate optical terahertz source based on an efficient 2-μm dual-wavelength KTP OPO

摘要

An efficient tunable high-repetition-rate KTP optical parametric oscillator (OPO) was deployed as a compact terahertz source. The KTP OPO was intracavity pumped by an acousto-optical (AO) Q-switched Nd:YVO4 laser and emitted two tunable wavelengths near degeneracy around 2 μm. A periodically inverted quasi-phase-matched (QPM) GaAs crystal and a GaSe crystal were used to generate terahertz (THz) wave of micro-watt level by the difference frequency generation (DFG) method. This provides a potential practical palm-top tunable THz sources for portable applications.