We have observed terahertz generation via injection current induced by harmonically related two-color beams in an unbiased ZnSe bulk at room temperature using a femtosecond Ti:sapphire oscillator. The terahertz intensity is just several times smaller than that obtained via optical rectification and further enhancements are believed possible. Experimental results demonstrate that the terahertz radiation is mainly attributed to the transition from the split-off band. This conclusion provides a novel approach to effectively generate a broadband and coherently controlled terahertz radiation, which leads to practical applications of terahertz radiation via this mechanism.
© 2012 Optical Society of America
Original Manuscript: October 13, 2011
Manuscript Accepted: November 11, 2011
Published: February 10, 2012
Zhihui Lü, Dongwen Zhang, Zhaoyan Zhou, Lin Sun, Zengxiu Zhao, and Jianmin Yuan, "Coherently controlled terahertz source for a time domain spectroscopy system via injection current in bulk ZnSe," Appl. Opt. 51, 676-679 (2012)