Terahertz Wave Generation via Nonlinear Parametric Process from ε -GaSe Single Crystals Grown by Liquid Phase Solution Method

Abstract

Terahertz (THz)-wave generation has been conducted based on difference frequency mixing (DFM) process with phonon-polariton excitation of ε-GaSe single crystals implemented with liq.-phase soln. growth using the temp. difference method under controlled vapor pressure for the first time. The type-eoo phase matching condition for the DFM process at around 10 THz is satisfied by changing the incident angle into the crystal. The max. conversion efficiency in the present DFG process is about 10-6 J-1 using a 0.1-mm-thick GaSe single crystal with the only ε- phase polytype, which can be greater than that of the com. available Bridgman grown GaSe crystal including both ε- and γ-phase polytypes. [on SciFinder(R)]