Zhang Yuping, Wu Zhixin, Shen Duanlong, Liu Meng, Yin Yiheng, Zhang Huiyun, Zhong Kai, Yao Jianquan. Theoretical Analysis of the Influence of Multi-Photon Absorptionon Terahertz Generation via ptical-Difference Frequency Generation[J]. Laser & Optoelectronics Progress, 2014, 51(3): 31901