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Room-temperature single-photon sources using solid-state emitters and open-access microcavities (Conference Presentation)

MetadataDetails
Publication Date2018-03-14
AuthorsSanmi Adekanye, Philip R. Dolan, A. A. P. Trichet, Sam Johnson, Jason M. Smith
InstitutionsUniversity of Oxford

Single photons are the key ingredient for many photonic quantum technologies including quantum key distribution and measurement-based quantum computing. However, it remains difficult to create devices with the appropriate specifications for use in non-laboratory environments. The optical microcavity platform provides an attractive route towards a room temperature single photon source device. Our ultra-small focused ion beam (FIB) milled open-access cavities offer enhancement of the spontaneous emission rate, tunability of the emission spectrum and increased light collection. The embedment of solid-state emitters within these cavities enables us to create a robust room temperature single photon source device, with the potential for high efficiencies and single photon purities. Defects such as the nitrogen-vacancy (NV) centre in diamond have been shown to be stable room-temperature sources of single photons. There are new single emitters emerging in two-dimensional materials such as hexagonal boron nitride (hBN). Here we present developments in room-temperature coupling of single defects to open-access microcavities of a planar-hemispherical geometry with mode volumes down to λ3. We report enhancements in the spectral density of photons into a single cavity mode, combined with improved single photon purities. It will be shown that the NV-cavity system provides a ~3% single photon emission efficiency with purities of up to 94%. The hBN-cavity system provides count rates >1Mcts/s into a single cavity mode with purities up to 96%. With these high single photon purities, such devices would be robust against photon number splitting attacks making them attractive for applications in quantum cryptography.