Numerical Computation And Imitation On Difference Frequency Generation Of Terahertz Ridiation

Terahertz radiation is usually referred to as electromagnetic wave with frequencies between the infrared and microwave, and it holds promise for a large number of important applications in various areas. While, for a long time, the developments in terahertz science and technology are very limited, as there is no applicable terahertz emitter is one of the key reasons in hindering it.The invention of laser gives people the hope to solve this problem. In recent years, many new methods has been attempted to gain terahertz emitters, and we made great progress.In this article, the three wave interaction equations are deduced from the Maxwell equations, under some reasonable approximations. Then, on the basis of the equations, a practicable method to generate terahertz is given. Some parameters such as the phase matching angle are calculated in theory.The characters of the output from optical parametric oscillators are obtained by numerical simulation, and terahertz radiation is generated by difference frequency generation in a GaSe crystal. At last, the conversion efficiency is discussed, and some methods to improve the conversion efficiency are given.