Modulation properties of terahertz waves going through a light excited high resistivity silicon wafer are analyzed and measured. Free carrier lifetime of the silicon wafer affects the modulation depth and speed of the terahertz wave. The lifetime is reduced to less than 1 μs by thermal processing for high speed modulation. Experimental results show that the response time and modulation depth of the proposed modulating structure are close to 1 μs and 51%, respectively.
© 2014 Chinese Optics Letters
Tao Li, Dongxiao Yang, and Jian Wang, "High speed optical modulation of terahertz waves using annealed silicon wafer," Chin. Opt. Lett. 12, 082501- (2014)