Cherenkov-Type Phase Matched Terahertz Wave Generation Using Difference Frequency Mixing with Lithium Niobate Crystal

Abstract

The authors demonstrated a Cherenkov-type phase-matching method for monochromatic THz-wave generation using the difference frequency generation process with a Li niobate crystal, which resulted in high conversion efficiency and wide tunability. The authors successfully generated monochromatic THz waves across the range 0.2-2.5 THz. The authors obtained efficient energy conversion in the low frequency region <0.5 THz, and achieved a flat tuning spectrum by varying the pumping wavelength during THz-wave tuning. Also, the authors decreased the phase-mismatch that originates in beam diam. by optimizing the pump beam shape with cylindrical lens. The increase of the THz-wave output was confirmed by decreasing the phase mismatching. [on SciFinder(R)]