We demonstrate a nanostructure composed of partially etched annular trenches in a suspended GaAs membrane, designed for efficient and moderately broadband (approx. 5 nm) emission extraction from single InAs quantum dots. Simulations indicate that a dipole embedded in the nanostructure center radiates upwards into free space with a nearly Gaussian far-field, allowing a collection efficiency > 80 % with a high numerical aperture (NA=0.7) optic, and with 12X Purcell radiative rate enhancement. Fabricated devices exhibit an approx. 10 % photon collection efficiency with a NA=0.42 objective, a 20X improvement over quantum dots in unpatterned GaAs. A fourfold exciton lifetime reduction indicates moderate Purcell enhancement.
@article{arxiv.1104.0271,
title = {A circular dielectric grating for vertical extraction of single quantum dot emission},
author = {M. Davanco and M. T. Rakher and D. Schuh and A. Badolato and K. Srinivasan},
journal= {arXiv preprint arXiv:1104.0271},
year = {2011}
}