Giant Tunable Faraday Effect in a Semiconductor Magneto-plasma for Broadband Terahertz Polarization Optics

TL;DR

This paper demonstrates a giant, tunable Faraday effect in n-InSb electron plasma using terahertz spectroscopy, enabling broadband, adjustable polarization devices for THz applications.

Contribution

It introduces a novel, large Faraday rotation in a semiconductor plasma at THz frequencies, with potential for tunable polarization optics.

Findings

Polarization rotation angles up to {}/2 at 0.3-2.5 THz

Ellipticity reaching 1 at a few Tesla magnetic fields

Theoretical simulations confirm experimental results

Abstract

We report on a giant Faraday effect in an electron plasma in n-InSb probed via polarization-resolved terahertz (THz) time-domain spectroscopy. Polarization rotation angles and ellipticities reach as large as {\pi}/2 and 1, respectively, over a wide frequency range (0.3-2.5 THz) at magnetic fields of a few Tesla. The experimental results together with theoretical simulations show its promising ability to construct broadband and tunable THz polarization optics, such as a circular polarizer, half-wave plate, and polarization modulators.