Modification of spontaneous emission from nanodiamond colour centres on a structured surface

F A Inam,M J Steel,J M Dawes,J R Rabeau,T Gaebel,L Stewart,C Bradac,M J Withford

doi:10.1088/1367-2630/13/7/073012

Abstract

Colour centres in diamond are promising candidates as a platform for quantum technologies and biomedical imaging based on spins and/or photons. Controlling the emission properties of colour centres in diamond is a key requirement for the development of efficient single-photon sources having high collection efficiency. A number of groups have achieved an enhancement in the emission rate over narrow wavelength ranges by coupling single emitters in nanodiamond crystals to resonant electromagnetic structures. In this paper, we characterize in detail the spontaneous emission rates of nitrogen-vacancy centres at various locations on a structured substrate. We found a factor of 1.5 average enhancement of the total emission rate when nanodiamonds are on an opal photonic crystal surface, and observed changes in the lifetime distribution. We present a model for explaining these observations and associate the lifetime properties with dipole orientation and polarization effects.

Highlights

In order to meet some of the demanding requirements for optical quantum technologies, bright sources of single photons [1,2,3,4,5] are required
For the nitrogen vacancy (NV) centre, the overall linewidth is of order 200 nm with the zero phonon line (ZPL) at 637 nm having a width of several nm at room temperature [15, 16]
We have presented detailed measurements of single photon emission lifetimes for NV centres in nanodiamonds on flat and structured surfaces

Summary

Introduction

In order to meet some of the demanding requirements for optical quantum technologies, bright sources of single photons [1,2,3,4,5] are required. A key challenge of diamond colour centres, as compared to other systems such as quantum dots, is the linewidth of the intrinsic emission spectrum. For the NV centre, the overall linewidth is of order 200 nm with the zero phonon line (ZPL) at 637 nm having a width of several nm at room temperature [15, 16]. The primary effect of coupling the centre to a cavity mode is a reshaping of the emission spectrum, with little increase in the overall rate of emitted photons. Some improvements are possible: under cryogenic conditions, the width of the zero phonon line does narrow [17] (though it remains significantly larger than the cavity linewidth) and a slightly stronger effect is expected. One could use other centres such as the nickel-related [18,19,20,21,22] group which have narrower intrinsic spectra (though again still broader than the cavity linewidth), the fabrication and spectroscopy of these centres are not as mature as for NV centres

Methods

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Discussion

Conclusion