Fresnel-type solid immersion lens for efficient light collection from quantum defects in diamond

Abstract

Quantum defects in diamonds have been studied as a promising resource for quantum science. The subtractive fabrication process for improving photon collection efficiency often require excessive milling time that can adversely affect the fabrication accuracy. We designed and fabricated a Fresnel-type solid immersion lens using the focused ion beam. For a 5.8 & mu;m -deep Nitrogen-vacancy symbolscript center, the milling time was highly reduced (1/3 compared to a hemispherical structure), while retaining high photon collection efficiency (> 2.24 compared to a flat surface). In numerical simulation, this benefit of the proposed structure is expected for a wide range of milling depths.& COPY; 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement