Diamond photonics platform based on silicon vacancy centers in a single-crystal diamond membrane and a fiber cavity

Abstract

We realize a potential platform for an efficient spin-photon interface, namely negatively-charged silicon-vacancy centers in a diamond membrane coupled to the mode of a fully-tunable, fiber-based, optical resonator. We demonstrate that introducing the thin (∼ 200 nm), single crystal diamond membrane into the mode of the resonator does not change the cavity properties, which is one of the crucial points for an efficient spin-photon interface. In particular, we observe constantly high Finesse values of up to 3000 and a linear dispersion in the presence of the membrane. We observe cavity-coupled fluorescence from an ensemble of SiV − centers with an enhancement factor of ∼ 1.9. Furthermore from our investigations we extract the ensemble absorption and extrapolate an absorption cross section of (2.9 ± 2) · 10 −12 cm 2 for a single SiV − center, much higher than previously reported.

Building Blocks for Quantum Network Based on Group‐IV Split‐Vacancy Centers in Diamond

“…Monolithic integration of these emitters in photonic structures helps boost the matter–photon interaction by tailoring the DOS of electromagnetic (EM) modes with respect to the patterned structure and/or cavity, a crucial phenomenon utilized to overcome the issue of low photon collection efficiency from high refractive index materials. In the past 20 years, thanks to the continuous developments of diamond‐based nanofabrication techniques and diamond synthetic methods, SiV − color centers have been successfully integrated in various photonic platforms, including nanopillar, waveguide, fiber‐based optical resonator, and nanocavity embedded in 1D or 2D photonic crystal.…”

Cryogenic platform for coupling color centers in diamond membranes to a fiber-based microcavity

“…Various approaches aim to improve the photon collection from solid-state emitters, employing solid immersion lenses [11,12], nanopillars [13] or waveguides [14]. Coupling the emitter to a nanophotonic [4,15,16], nanofiberbased [17] or open [18][19][20][21][22] optical cavity can be used to both enhance the emission into the zero-phonon line (ZPL) for emitter species with small Debye-Waller factors, like the NV − center, as well as to funnel the emission into a well-collectable optical mode via the Purcell effect. While photonic crystal cavities are attractive due to strong mode confinement [15] and their intrinsic robustness, processing the crystal environment can lead to spectral diffusion and the optical outcoupling of the signal is challenging [23].…”

“…However, the embedded emitters often suffer from spectral diffusion [31] and insufficient photostability [30]. Recently, micrometer thin diamond membranes [32] have shown to be promising hosts for color centers used in microcavity experiments [19,21,22].…”

Transverse-mode coupling effects in scanning cavity microscopy

“…The observed effects are also relevant for cavity QED experiments, in particular with solid-state emitters e.g. for the case of color centers in diamond, where thin diamond membranes are integrated into open-access cavities [9,13,14,33], mode coupling due to imperfect membrane surfaces can additionally affect the mode structure and limit the operation conditions for emitter-cavity coupling experiments.…”