Nonreciprocal reflection of mid-infrared light by highly doped InAs at low magnetic fields

TL;DR

This study demonstrates room-temperature nonreciprocal mid-infrared light reflection from highly doped InAs surfaces at low magnetic fields, advancing potential applications in thermal management and magnetic sensing.

Contribution

It provides experimental evidence of nonreciprocal reflection in InAs at low magnetic fields, a step toward practical nonreciprocal optical devices.

Findings

Nonreciprocal reflection observed at magnetic fields as low as 0.07 T.

Nonreciprocal reflectance contrast increases with magnetic field strength.

Nonreciprocal effects demonstrated for p-polarized mid-infrared light.

Abstract

We report an experimental observation of room-temperature nonreciprocal reflection of mid-infrared light from planar highly doped InAs surfaces at low magnetic fields ranging from 0.07 T to 0.16 T. Using ellipsometry, we demonstrate that the amplitude ratio and phase shift of reflected light are nonreciprocal in the Voigt configuration. We also demonstrate using Fourier-transform infrared spectroscopy that the nonreciprocal reflectance contrast (the difference in reflectance in opposite directions) increases with the magnitude of the magnetic field for p-polarized light. Our work is a step toward the practical implementation of nonreciprocal thermal emitters and absorbers and applications such as remote magnetic field sensing.