Ultra-thin, single-layer polarization rotator

T V Son,P A Do,A Haché,V V Truong

doi:10.1063/1.4960552

Abstract

We demonstrate light polarization control over a broad spectral range by a uniform layer of vanadium dioxide as it undergoes a phase transition from insulator to metal. Changes in refractive indices create unequal phase shifts on s- and p-polarization components of incident light, and rotation of linear polarization shows intensity modulation by a factor of 103 when transmitted through polarizers. This makes possible polarization rotation devices as thin as 50 nm that would be activated thermally, optically or electrically.

Highlights

The need for compact polarization rotators in displays and integrated optics is driving research for functional materials with optical activity and controllable anisotropy
We demonstrate light polarization control over a broad spectral range by a uniform layer of vanadium dioxide as it undergoes a phase transition from insulator to metal
Liquid crystals achieve 90 degrees polarization rotations over lengths of about one micrometer, and recent advances in transparent magneto-optic materials combined with photonic crystal technology has created devices with roughly the same thickness.[1,2]

Summary

INTRODUCTION

The need for compact polarization rotators in displays and integrated optics is driving research for functional materials with optical activity and controllable anisotropy. We investigate vanadium dioxide as a candidate for ultrathin, controllable polarization rotating devices. In this material, a phase transition from insulator to metal occurs at the relatively low critical temperature of Tc = 68 ◦C, which coincides with large changes in refractive indices. A phase transition from insulator to metal occurs at the relatively low critical temperature of Tc = 68 ◦C, which coincides with large changes in refractive indices Exploiting this effect, we demonstrate broadband, highly efficient polarization control by a single layer with thicknesses from 50 to 100 nm.

Substrate Zerodur Glass Quartz

With zr

CONCLUSIONS