Arbitrary helicity control of circularly polarized light from lateral-type spin-polarized light-emitting diodes at room temperature

TL;DR

This paper demonstrates fast, arbitrary control of circular polarization in light emitted from a lateral spin-LED at room temperature, using electrical currents to switch and tune polarization states.

Contribution

It introduces a method for electrical, high-speed, arbitrary helicity control of CPL in lateral spin-LEDs at room temperature, advancing practical polarization sources.

Findings

CPL polarization can be switched at frequencies up to 100 kHz.

Degree of circular polarization can be tuned by current density ratio.

Room temperature operation of the lateral spin-LEDs is achieved.

Abstract

We demonstrate arbitrary helicity control of circularly polarized light (CPL) emitted at room temperature from the cleaved side-facet of a lateral-type spin-polarized light-emitting diode (spin-LED) with two ferromagnetic electrodes in an anti-parallel magnetization configuration. Driving alternate currents through the two electrodes results in polarization switching of CPL with frequencies up to 100 kHz. Furthermore, tuning the current density ratio in the two electrodes enables manipulation of the degree of circular polarization. These results demonstrate arbitrary electrical control of polarization with high speed, which is required for the practical use of lateral-type spin-LEDs as monolithic CPL light sources.