Circularly-Polarized Light Emission from Semiconductor Planar Chiral Photonic Crystal

TL;DR

This paper demonstrates a novel surface-emitting circularly polarized light source using a chiral photonic crystal, achieving significant polarization at room temperature through vacuum field imbalance.

Contribution

It introduces a new scheme for circularly polarized light emission by manipulating vacuum fields in a chiral photonic structure, with experimental validation.

Findings

Achieved up to 25% polarization at room temperature.

Observed circularly polarized spontaneous emission from quantum dots.

Numerical simulations show vacuum field mode modifications.

Abstract

We proposed and demonstrated a scheme of surface emitting circularly polarized light source by introducing strong imbalance between left- and right-circularly polarized vacuum fields in an on-waveguide chiral grating structure. We observed circularly polarized spontaneous emission from InAs quantum dots embedded in the wave guide region of a GaAs-based structure. Obtained degree of polarization reaches as large as 25% at room temperature. Numerical calculation visualizes spatial profiles of the modification of vacuum field modes inside the structure with strong circular anisotropy.