CC BY
2*
ALT'23 The 30th International Conference on Advanced Laser Technologies
P-O-1
Dielectric microcavities as a platform for effective single photon emission of a color centers in nanodiamonds
A. Romshin1, D. Pasternak1, R. Bagramov2, V. Filonenko2, A. Zhivopistsev1, I. Vlasov1
1-Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991, Moscow, Russia 2- Vereshchagin Institute of High Pressure Physics RAS, Moscow, Russia
alex_31 [email protected]
A cavity quantum electrodynamics provides the platforms for implementation of effective single photon source (SPS) - a key node in realization of scalable quantum networks [1]. To maximize the efficiency and fidelity of operations at this node, the SPS' emission have to satisfy criteria of high brightness, radiation directivity and narrowness of spectral line. For these purposes, optical cavities with low energy loss and high emitter-cavity coupling strength are required to make use of the Purcell-enhancement of the radiative decay
3
3
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by a factor F = —- • — — (Q - quality factor, V - mode volume) into a cavity mode of interest and
p 4n2 {n) V
thereby achieve a deterministic bit stream of single-photon pulses [2]. While there are many optical cavities, most of them suffer from excessive absorption and intrinsic mode mismatch between emitter and cavity.
In present work, we demonstrate an effective tunable coupling of the single photon emitter in nanodiamond (ND) placed in fully dielectric low-loss Fabry-Perot microcavity. The cavity consists from two macroscopic dielectric mirrors: the former (R>99.999%) is planar, the latter (R>99.95%) contains an array of concave holes with diameters of 4 and 16 ^m. The finesse of the cavity is measured by transmission spectroscopy to be F~3000 at 740 nm. As an emitter we use single negatively charged silicon-vacancy (SiV)-centers formed in ND. The SiV fluorescence is characterized by a narrow (1-7 nm) zero-phonon line (ZPL) at 738 nm, in which ~70% of the SiV emission is concentrated, and demonstrates high spectral and time stability [3]. NDs were deposited onto the surface of the planar mirror from the water droplet. By means of confocal spectroscopy and Hanbury-Brown-Twiss interferometry, the fluorescence spectra and saturation curves of individual SPS were measured and the results were quantitively compared for the cases an emitter is in free space and inside cavity. An ability to change the distance between mirrors in microscale allowed us to spectrally overlap desirable cavity mode and ZPL of the SiV-center. So, such a dielectric microcavity revealed more than order enhancement of single photon emission accompanied with Fp~3 and peak coupling efficiency of Z~75%.
The work was supported by the grant of the Russian Science Foundation No. 22-19-00324.
[1] N. Gisin, G. Ribordy, W. Tittel, and H. Zbinden, Quantum cryptography, Rev. Mod. Phys. 74, 145 (2002).
[2] E. Purcell, Spontaneous emission probabilities at radio frequencies, Phys. Rev. 69, 681 (1946).
[3] I. Vlasov, A. Barnard, V. Ralchenko, O. Lebedev, M. Kanzyuba, A. Saveliev, V. Konov and E. Goovaerts. Nanodiamond photoemitters based on strong narrow-band luminescence from silicon-vacancy defects Adv. Mater., 21, 808-12 (2009).
