Enhanced photon-extraction efficiency from InGaAs/GaAs quantum dots in deterministic photonic structures at 1.3 \mu m fabricated by in-situ electron-beam lithography

TL;DR

This paper demonstrates a method to enhance photon extraction efficiency from InGaAs/GaAs quantum dots at 1.3 μm using in-situ electron-beam lithography, enabling more efficient telecom-range quantum light sources.

Contribution

It introduces a deterministic fabrication technique for quantum dots integrated into photonic structures at telecom wavelengths, improving photon extraction efficiency.

Findings

Achieved 10% photon extraction efficiency at 1.3 μm.

Demonstrated agreement between experimental results and finite-element simulations.

Validated the use of in-situ electron-beam lithography for quantum dot integration.

Abstract

The main challenge in the development of non-classical light sources remains their brightness that limits the data transmission and processing rates as well as the realization of practical devices operating in the telecommunication range. To overcome this issue, we propose to utilize universal and flexible in-situ electron-beam lithography and hereby, we demonstrate a successful technology transfer to telecom wavelengths. As an example, we fabricate and characterize especially designed photonic structures with strain-engineered single InGaAs/GaAs quantum dots that are deterministically integrated into disc-shaped mesas. Utilizing this approach, an extraction efficiency into free-space (within a numerical aperture of 0.4) of (10${\pm}$2) % has been experimentally obtained in the 1.3 \mu m wavelength range in agreement with finite-element method calculations.