Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

A circular dielectric grating for vertical extraction of single quantum dot emission



Marcelo I. Davanco, Matthew T. Rakher, Dieter Schuh, Antonio Badolato, Kartik A. Srinivasan


We demonstrate a suspended circular grating composed of partially etched annular trenches in a thin GaAs membrane, designed for e±cient and moderately broadband ( approx. 5 nm) extraction of emission from single InAs quantum dots. Simulations indicate that a single dipole embedded in the center of the nanostructure radiates upwards into free space with a nearly Gaussian far-feld, allowing a collection e±ciency > 80% with a high numerical aperture (NA=0.7) optic, and with 12 times Purcell radiative rate enhancement. Fabricated devices exhibit a 10 % photon collection effciency with a NA=0.42 objective, a 20 times improvement over quantum dots in unpatterned GaAs. A fourfold reduction in quantum dot exciton lifetime is observed, suggesting moderate Purcell enhancement.
Applied Physics Letters
Created July 25, 2011, Updated February 19, 2017