Instabilities in nanodiamond nitrogen-vacancy centre single photon sources under prolonged pulsed excitation

Journal article

Colour centres in nanodiamonds provide robust sources of fluorescence and can be used as triggered sources of single photons at room temperature. However, practical devices require stability over thousands of hours of operation, and the use of strong pulsed optical excitation, placing significant burden on the robustness of the emitters that requires bespoke testing. In this work we report the response of single NV centres in nanodiamonds of 50 nm and 100 nm diameter to accelerated lifetime testing, exciting the defects close to saturation around 1013 times to simulate the minimum operational lifetime of a practical device. For nanodiamonds 50 nm in diameter, observed changes in the fluorescence intensity and lifetime suggest a progressive size reduction as a result of the pulsed laser excitation, combined with the introduction of non-radiative centres on or near the nanodiamond surface which affect the quantum efficiency of the NV centre and ultimately lead to photobleaching of the emission. We find examples of NV centres in 100 nm nanodiamonds for which triggered single photon emission remains stable for over these accelerated lifetime tests, demonstrating their suitability for use in practical devices.

Authors: Aspinall, J; Adekanye, SO; Brown, I; Dhawan, AR; Smith, JM

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Optical Society of America
• Journal: Optical Materials Express
• Volume: 10
• Issue: 2
• Pages: 332-341
• Publication date: 2020-01-07
• Acceptance date: 2019-11-25
• DOI: 10.1364/OME.10.000332
• EISSN: 2159-3930
• Language: English
• Keywords: FFR