Dynamic Tunable Deflection of Radiation Based on Epsilon-Near-Zero Material

Epsilon-near-zero nanoantennas can be used to tune the far-field radiation pattern due to their exceptionally large intensity-dependent refractive index. In this study, we propose a hybrid optical antenna based on indium tin oxide (ITO) to enable optical tuning of the deflection of radiation, specifically a hybrid structure antenna of ITO and dielectric material, which makes the deflection angle changes 17 degrees as incident intensities increase. Moreover, by employing an array of ITO or hybrid nanodisks, we can enhance the unidirectionality of the radiation pattern, resulting in a needle-like shape with an angular beam width a < 8 degrees of the main lobe. The deflection angle of the radiation pattern response with the needle-like lobe paves the way for further studies and applications in beam steering and optical modulation where dynamic control of the nanoantennas is highly desirable.