Efficient terahertz generation by optical rectification in Si-LiNbO3-air-metal sandwich structure with variable air gap

Abstract

A record high optical-to-terahertz conversion efficiency of 0.25% was realized with femtosecond laser pulses propagated in a planar Si-LiNbO3-air-metal structure. Terahertz spectrum tuning was demonstrated by adjusting an air gap between the LiNbO3 layer and the metal plate. The influence of optical pulse chirp on the efficiency of terahertz generation was investigated.