Polarization-selective enhancement of telecom wavelength quantum dot transitions in an elliptical bullseye resonator

TL;DR

This paper demonstrates broadband polarization-selective enhancement of telecom wavelength quantum dot emissions using an elliptical bullseye resonator, achieving high polarization purity, increased emission rates, and compatibility with compact cooling systems.

Contribution

It introduces a novel elliptical bullseye resonator for polarization-selective enhancement of quantum dot emissions at telecom wavelengths, enabling practical quantum light sources.

Findings

Achieved 96% linear polarization degree in emitted photons.

Reported Purcell factor of 3.9 and count rates up to 3 MHz.

Operated device at temperatures up to 40 K, compatible with compact cryocoolers.

Abstract

Semiconductor quantum dots are promising candidates for the generation of nonclassical light. Coupling a quantum dot to a device capable of providing polarization-selective enhancement of optical transitions is highly beneficial for advanced functionalities such as efficient resonant driving schemes or applications based on optical cyclicity. Here, we demonstrate broadband polarization-selective enhancement by coupling a quantum dot emitting in the telecom O-band to an elliptical bullseye resonator. We report bright single-photon emission with a degree of linear polarization of 96%, Purcell factor of 3.9, and count rates up to 3 MHz. Furthermore, we present a measurement of two-photon interference without any external polarization filtering and demonstrate compatibility with compact Stirling cryocoolers by operating the device at temperatures up to 40 K. These results represent an important step towards practical integration of optimal quantum dot photon sources in deployment-ready setups.