Robust, tunable, and high purity triggered single photon source at room temperature using a nitrogen-vacancy defect in diamond in an open microcavity

Abstract

We report progress in the development of tunable room temperature triggered single photon sources based on single nitrogen-vacancy (NV) centres in nanodiamond coupled to open access optical micro-cavities. The feeding of fluorescence from an NV centre into the cavity mode increases the spectral density of the emission and results in an output stream of triggered single photons with spectral line width of order 1 nm, tunable in the range 640 - 700 nm. We record single photon purities exceeding 96% and estimated device efficiencies up to 3%. We compare performance using plano-concave microcavities with radii of curvature from 25 μm to 4 μm and show that up to 17% of the total emission is fed into the TEM mode. Pulsed Hanbury-Brown Twiss (HBT) interferometry shows that an improvement in single photon purity is facilitated due to the increased spectral density.

High-throughput nitrogen-vacancy center imaging for nanodiamond photophysical characterization and pH nanosensing

“…A custom-built confocal set-up was used to perform spectral measurement and photon correlation experiments as we previously reported. 41 …”

“…A custom-built confocal set-up was used to perform spectral measurement and photon correlation experiments as we previously reported. 41 For pH sensing, the 10 nm NDs were immersed in different buffer solutions using silicone gaskets to form wells. A 0.01 M HCl solution was used for pH 1.2; a 0.1 M NaOH solution for pH 12.8-12.9; a 1× phosphate-buffered saline solution (PBS) for pH 7; a commercial buffer solution (Hanna instruments) was used for pH 4 and 10.…”

Multimode Vibrational Strong Coupling of Methyl Salicylate to a Fabry–Pérot Microcavity

“… − The open Fabry–Pérot IR microcavity used in this work consists of two Au mirrors, prepared on circular CaF 2 windows ( d = 25.0 mm, 5.0 mm thickness) by a high vacuum sputtering (Leica EM MED 020). The thickness of the Au film was controlled using a quartz crystal balance as a reference during sputtering.…”

Tunable Open‐Access Microcavities for Solid‐State Quantum Photonics and Polaritonics

“…Dolan et al. demonstrated in the same type of cavity single‐photon generation, which exhibited photon purities exceeding 96% and device efficiencies up to 3% . The authors also carried out systematic studies using concave mirrors with a series of RoCs ranging from 4 to 25 µm, and concluded that RoC = 8 µm enabled the best device performance by the interplay between cavity feeding and photon extraction.…”