Chip-integrated plasmonic cavity-enhanced single nitrogen-vacancy center emission

TL;DR

This paper presents a chip-integrated plasmonic cavity that enhances and narrows the emission of single nitrogen-vacancy centers in diamond, achieving significant emission rate enhancement and tunable resonance.

Contribution

It introduces a novel cavity design integrated with a dielectric-loaded SPP waveguide that significantly enhances NV center emission at room temperature.

Findings

Achieved a cavity quality factor of ~70.

Demonstrated up to 42-fold spontaneous emission rate enhancement.

Realized full tunability of the cavity resonance wavelength.

Abstract

High temporal stability and spin dynamics of individual nitrogen-vacancy (NV) centers in diamond crystals make them one of the most promising quantum emitters operating at room temperature. We demonstrate a chip-integrated cavity-coupled emission into propagating surface plasmon polariton (SPP) modes narrowing NV center's broad emission bandwidth with enhanced coupling efficiency. The cavity resonator consists of two distributed Bragg mirrors that are built at opposite sides of the coupled NV emitter and are integrated with a dielectric-loaded SPP waveguide (DLSPPW), using electron-beam lithography of hydrogen silsesquioxane resist deposited on silver-coated silicon substrates. A quality factor of ~ 70 for the cavity (full width at half maximum ~ 10 nm) with full tunability of the resonance wavelength is demonstrated. An up to 42-fold decay rate enhancement of the spontaneous emission at the cavity resonance is achieved, indicating high DLSPPW mode confinement.