Terahertz wave generation using type II phase matching polarization combination via difference frequency generation with LiNbO sub(3)

We present terahertz (THz) wave generation using type II phase matching polarization combination via difference frequency generation (DFG) with lithium niobate (LiNbO sub(3)) crystal. A collinear phase matching has not been realized so far because LiNbO sub(3) crystal has a large absorption and high refractive index dispersion. In this paper we proposed that using type II phase matching is able to avoid these defects and generate the THz wave. We experimentally demonstrated the forward and backward collinear type II phase matching method, and confirmed that THz wave is generated by using simple equipment. This method will be applied for the applications for a small THz wave sources.