Excitation of exciton-polariton vortices in pillar microcavities by a Gaussian beam

TL;DR

This study investigates how Gaussian pump beams excite and control vortex and antivortex structures in exciton-polariton microcavities, revealing dependence on cavity parameters and nonlinear interactions, with potential applications in optical interferometry.

Contribution

It provides a detailed analysis of vortex excitation mechanisms in microcavities using coupled Gross-Pitaevskii equations, highlighting the influence of pump geometry and nonlinear effects.

Findings

Weak Gaussian beams can excite vortex-antivortex pairs and high angular momentum states.

Vortex structures depend strongly on microcavity radius and pump geometry.

Nonlinear exciton interactions limit vortex excitation with stronger beams.

Abstract

With coupled Gross-Piteavskii equations we study excitation of exciton-polariton vortices and antivortices in a pillar microcavity by a Gaussian pump beam. The structure of vortices and antivortices shows a strong dependence on the microcavity radius, pump geometry, and nonlinear exciton-exciton interaction. Due to the nonlinear interaction the strong Gaussian beam cannot excite more polariton vortices or antivortices with respect to the weak one. The calculation demonstrates that the weak Gaussian beam can excite vortex-antivortex pairs, vortices with high angular momentum, and superposition states of vortex and antivortex with high opposite angular momentum. The pump geometry for the Gaussian beam to excite these vortex structures are analyzed in detail, which holds a potential application for Sagnac interferometry and generating the optical beams with high angular momentum.