Optical characterization and selective addressing of the resonant modes of a micropillar cavity with a white light beam

TL;DR

This study demonstrates spatially resolved optical characterization of GaAs/AlAs micropillar cavity modes using white-light reflectivity, enabling selective mode addressing and matching experimental coupling efficiencies.

Contribution

It introduces a method to resolve and selectively address individual cavity modes in micropillars via spatial scanning with white light.

Findings

Spatial field distribution of modes resolved in real space

Selective addressing of single cavity modes achieved

Coupling efficiencies match theoretical calculations

Abstract

We have performed white-light reflectivity measurements on GaAs/AlAs micropillar cavities with diameters ranging from 1 {\mu}m up to 20 {\mu}m. We are able to resolve the spatial field distribution of each cavity mode in real space by scanning a small-sized beam across the top facet of each micropillar. We spectrally resolve distinct transverse optical cavity modes in reflectivity. Using this procedure we can selectively address a single mode in the multimode micropillar cavity. Calculations for the coupling efficiency of a small-diameter beam to each mode are in very good agreement with our reflectivity measurements.