Microscopic diamond Solid-Immersion-Lenses fabricated around single defect ceneters by focussed ion beam milling

TL;DR

This paper discusses the fabrication of microscopic solid-immersion-lenses in diamond around single NV centers using focused ion beam milling, improving photon collection efficiency for quantum applications.

Contribution

It introduces a method to accurately locate single NV centers and optimize SIL fabrication, enhancing photon collection from quantum emitters in diamond.

Findings

Achieved a count rate of 1.0 million counts per second with a [111] NV center.

Demonstrated precise positioning of SILs around single quantum emitters.

Compared emitter characteristics before and after SIL fabrication.

Abstract

Recent efforts to define microscopic solid-immersion-lenses (SIL) by focused ion beam milling into diamond substrates that are registered to a preselected single photon emitter are summarized. We show how we determine the position of a single emitter with at least 100 nm lateral and 500 nm axial accuracy, and how the milling procedure is optimized. The characteristics of a single emitter, a Nitrogen Vacancy (NV) center in diamond, are measured before and after producing the SIL and compared with each other. A count rate of 1.0 million counts per second is achieved with a $[111]$ oriented NV center.