Bright quantum dot light sources using monolithic microlenses on gold back-reflectors
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
We demonstrate a scalable method for fabricating bright GaAs quantum dot (QD) photon sources by embedding them into broadband monolithic AlGaAs microlens arrays on gold-coated GaAs substrates. Cylindrical photoresist templates (2-5 µm diameter) are thermally reflowed and transferred into AlGaAs thin films using an optimized 3D reactive ion etching process. This yields large-area (2 mm × 4 mm), high-density (∼ 40 × 10 3 mm−2) microlens arrays of uniform shape. The brightest QD emissions are found in lenses with 2.7 µm diameter and 1.35 µm height. Finite-difference time-domain simulations of lens geometries reveal optimization potentials, including anti-reflection coatings. It is found that free-space and fiber-coupled extraction efficiencies can reach up to 62% and 37%, respectively. A statistical fabrication model, validated through photoluminescence spectroscopy, shows intensity enhancements up to × 200 in ca. 1 out of 200 lenses, aligning well with theoretical predictions. This approach highlights the promise of compact, efficient photon sources for future large-scale quantum network applications.
Details
| Original language | English |
|---|---|
| Article number | 225301 |
| Journal | Nanotechnology |
| Volume | 36 |
| Issue number | 22 |
| Publication status | Published - 2 Jun 2025 |
| Peer-reviewed | Yes |
External IDs
| PubMed | 40315872 |
|---|---|
| ORCID | /0000-0001-8469-9573/work/203069097 |
Keywords
ASJC Scopus subject areas
Keywords
- 3D-micro engineering, nanophotonics, quantum dots, quantum light sources, semiconductor Heterostructures