Progress on Terahertz Excitation of Organic Nonlinear Crystals

Organic nonlinear crystals have a great potential in generating terahertz waves. Organic nonlinear optical crystals require simpler collinear phase matching conditions and lower pump energy than inorganic nonlinear optical crystals. Their properties such as refractive index, dispersion, phonon mode and absorption properties are beneficial to the generation of terahertz and other nonlinear optical processes. The research progress of two organic nonlinear crystals exciting terahertz of pyridinium-based DAST [(4-(4-(dimethylamino)styryl)-1-methylpyridinium 4-methylbenzenesulfonate)] and quinoxaline-based HMQ-TMS [2-(4-hydroxy-3-methoxystyryl)-1-methylquinolinium 2,4,6-trimethylbenzenesulfonate] is mainly reviewed and other organic nonlinear crystals are briefly reviewed in this article.