Tunable Metasurface for Dynamic Control of Polarization in Near-Infrared

Pin Chieh Wu^1*

¹Department of Photonics, National Cheng Kung University, Taiwan

* Presenter:Pin Chieh Wu, email:pcwu@gs.ncku.edu.tw

Optical polarization performs a key characteristic of electromagnetic waves that has a significant impact on the number of applications, such as information delivery, 3D imaging technique, and quantum computations. Metasurfaces composed of planar structures have attracted a huge number of interests due to their ability on controlling the electromagnetic phase as well as amplitude at a subwavelength scale. The feasible applications based on metasurfaces include nonlinear dynamics, light beam shaping, quantum computation, etc. Besides those promising characteristics, people also intend to discover the field of versatile polarization generation in a compact device dimension. They will pave a way for the development of flat optical devices and integrated optoelectronic systems, and toward the far-reaching applications which are impossible previously. In this talk, we demonstrate that the polarization state of the light reflected from an indium tin oxide (ITO)-based active metasurface can be dynamically controlled. By suitably biasing between the ITO layer and back reflector, the linearly-polarized incident light can be actively converted to a cross-polarized, circularly-polarized or elliptically-polarized light. This dynamic control of the amplitude, phase as well as polarization state of the scattered beam provides prospects for various applications, such as spatial light modulators and adaptive wavefront control.

Keywords: Tunable polarization, Active metasurface, Transparent conducting oxide, Epsilon-near-zero