Extinction of Light and Coherent Scattering by a Single Nitrogen-Vacancy Center in Diamond

TL;DR

This paper demonstrates efficient coupling of a laser to a single nitrogen-vacancy center in diamond, enabling direct measurement of extinction and coherent scattering, with implications for quantum information applications.

Contribution

It introduces experimental techniques to measure extinction and coherent scattering from a single NV center, and models spectral diffusion effects.

Findings

Detected direct extinction signal from a single NV center.

Identified optimal excitation conditions for coherent photon generation.

Measured properties of tight focusing and Gouy-phase in the experimental setup.

Abstract

Coherently scattered light from a single quantum system promises to get a valuable quantum resource. In this letter an external laser field is efficiently coupled to a single nitrogen vacancy (NV-)center in diamond. By this it is possible to detect a direct extinction signal and estimate the NV's extinction cross-section. The exact amount of coherent and incoherent photons is determined against the saturation parameter, and reveals the optimal point of generating coherently scattered photons and an optimal point of excitation. A theoretical model of spectral diffusion allows to explain the deviation to an atom in free-space. The introduced experimental techniques are used to determine the properties of the tight focusing in an interference experiment, and allow for a direct determination of the Gouy-phase in a strongly focused beam.