Design for dynamic wavefront manipulation based on phase change materials

Abstract

In the past decades, metasurfaces have shown their extraordinary ability to manipulate the wavefront of electromagnetic wave. However, the most of previously proposed designs based on metasurfaces are fixed once design, which are unsuitable for applications where light manipulation needs to be dynamically. In this paper, we proposed a design for dynamic wavefront manipulation achieved by the combination of metasurfaces and phase change materials (PCM) in the near infrared spectral range. Here, we present a metal-insulator-metal (MIM) configuration with the polarization conversion exceeding 80% for circular polarized (CP) light converted to its opposite handedness when PCM is in the amorphous state, but the efficiency turns to 0 when PCM switch into its crystalline state. By utilizing the Pancharatnam- Berry (PB) phase, we can achieve the dynamic wavefront manipulation between the amorphous and crystalline states. As a proof-of-concept, a deflector and focus lens are designed and characterized, and the results further verify the ability for dynamic wavefront manipulation. It is believed that the design in our work may pave the way towards the dynamic manipulation of light.