Broadband fluorescence collection efficiency enhancement system based on a short-focal-length metalens
Phys. Rev. Applied 26, 044094 – Published 30 October, 2026
DOI: https://doi.org/10.1103/sm6w-tcfv
Abstract
Efficient fluorescence collection is essential for precise quantum measurements based on nitrogen-vacancy (NV) centers in diamond. However, photon extraction is limited by total internal reflection at the diamond-air interface. To address this challenge, we propose a short-focal-length metalens on a support for broadband fluorescence collection over 600–800 nm in an ensemble-NV ODMR system. The metalens is designed as a compact replacement for the conventional lens collection path. FDTD simulations show that the metalens improves the forward photon collection efficiency by a factor of 3.2 compared with bare diamond. Experimentally, ODMR measurements show fluorescence-related signal enhancements of 33% and 45% for microring and double-split-ring microwave antennas, respectively. These results confirm that the proposed design provides an effective and compact solution for enhancing fluorescence collection in diamond-based quantum sensing systems.
