Abstract-Efficient terahertz generation by cascaded difference frequency generation based on cavity phase matching

Shijia Zeng, Fangsen Xie, Zhiming Rao

http://iopscience.iop.org/article/10.1088/1555-6611/aada3e

In this paper, a scheme for cascaded difference frequency generation based on cavity phase matching is proposed using the structure of a sheet cavity, in which the conditions for both the resonance and nonlinear interaction between the pump and THz wave are considered. Numerical simulations show that a prominent cascading effect can occur when the pump wavelengths are 9.55 µm [9P(20)] and 9.79 µm [9P(46)] for a cavity length of 756.6 µm; for such a configuration, the peak power conversion efficiency can be as high as 4.31%, with a photon conversion efficiency of 174.8% at 53 °C, which exceeds the Manley–Rowe limit. Our results are expected to contribute to the development of small THz sources, with potential for application to doubly resonant or triply resonant nonlinear optics.