Graphene based all-optical spatial terahertz modulator

Authors

Qi-Ye Wen, University of Electronic Science and Technology of China
Wei Tian, University of Electronic Science and Technology of China
Qi Mao, University of Electronic Science and Technology of China
Zhi Chen, University of Electronic Science and Technology of China
Wei-Wei Liu, Nankai University
Qing-Hui Yang, University of Electronic Science and Technology of China
Matthew Sanderson, University of WollongongFollow
Huai-Wu Zhang, University of Electronic Science and Technology of China

RIS ID

97235

Publication Details

Wen, Q., Tian, W., Mao, Q., Chen, Z., Liu, W., Yang, Q., Sanderson, M. & Zhang, H. (2014). Graphene based all-optical spatial terahertz modulator. Scientific Reports, 4 1-5.

Abstract

We demonstrate an all-optical terahertz modulator based on single-layer graphene on germanium (GOG), which can be driven by a 1.55 mu m CWlaser with a low-level photodoping power. Both the static and dynamic THz transmission modulation experiments were carried out. Aspectrally wide-band modulation of the THz transmission is obtained in a frequency range from 0.25 to 1 THz, and a modulation depth of 94% can be achieved if proper pump power is applied. The modulation speed of the modulator was measured to be similar to 200 KHz using a 340 GHz carrier. A theoretical model is proposed for the modulator and the calculation results indicate that the enhanced THz modulation is mainly due to the third order nonlinear effect in the optical conductivity of the graphene monolayer.