Friday, July 6, 2018

Abstract-Semiconductor terahertz modulator arrays: the size and edge effect

Tianlong Wen, Chong Zhang, Xiaochen Zhang, Yulong Liao, Quanjun Xiang, Qiye Wen, Dainan Zhang, Yuanpeng Li, Huaiwu Zhang, Yulan Jing, and Zhiyong Zhong

A terahertz spatial modulator is the critical component for active terahertz imaging using compressive sensing. Here small silicon pieces were put in arrays on flexible polymer substrate to fabricate semiconductor terahertz spatial modulators. By doing this, the inter-diffusion of photo-generated charge carriers is prevented for better resolution, and flexibility is achieved. Since the size of silicon is comparable to the wavelength of the terahertz wave, and the dielectric properties of the gap are very different from silicon, the optical modulation of each element is very different from the large silicon. In this Letter, the terahertz wave interaction and optical modulation of the small silicon are systematically studied by time domain spectroscopy. Notably, a strong resonance-like absorption peak was observed in a transmittance spectrum for the small silicon due to the size and edge effect. The spatial modulation of the terahertz wave was also compared between the silicon array and the large silicon samples.
© 2018 Optical Society of America

No comments: