Abstract

Recent studies have focused on the demonstration of active nano-devices whose optical properties can be controlled electrically for applications. Studies using electro-optical materials, such as graphene, phase change materials, and transparent conducting oxides have been reported [1-3]. In particular, indium tin oxides (ITOs) have attracted a lot of attention owing to outstanding electro-optical characteristics, where the refractive index change reaches unity if biased in near-infrared range. However, the thickness of charge accumulation layer of which the refractive index changes is about only 1 nm when electric field is applied on ITO. In addition, owing to the structural limitation for applying the voltage, so far, only research on reflection-type with metal layers has been reported.

© 2017 Japan Society of Applied Physics, Optical Society of America