%A Zhongyang Li(李忠洋), Jia Zhao(赵佳), Wenkai Liu(刘文锴), Qingfeng Hu(胡青峰), Yongjun Li(李永军), Binzhe Jiao(焦彬哲), Pibin Bing(邴丕彬), Hongtao Zhang(张红涛), Lian Tan(谭联), and Jianquan Yao(姚建铨) %T Theoretical research on terahertz wave generation from planar waveguide by optimized cascaded difference frequency generation %0 Journal Article %D 2021 %J Chin. Phys. B %R 10.1088/1674-1056/abc3b7 %P 24209-0 %V 30 %N 2 %U {https://cpb.iphy.ac.cn/CN/abstract/article_123222.shtml} %8 2021-01-18 %X A novel scheme for high-efficiency terahertz (THz) wave generation based on optimized cascaded difference frequency generation (OCDFG) with planar waveguide is presented. The phase mismatches of each-order cascaded difference frequency generation (CDFG) are modulated by changing the thickness of the waveguide, resulting in a decrement of phase mismatches in cascaded Stokes processes and an increment of phase mismatches in cascaded anti-Stokes processes simultaneously. The modulated phase mismatches enhance the cascaded Stokes processes and suppress the cascaded anti-Stokes processes simultaneously, yielding energy conversion efficiencies over 25% from optical wave to THz wave at 100 K.