Hybrid Photonic-Plasmonic Cavity Design for Very Large Purcell Factors at Telecommunication Wavelengths

Abstract

[EN] Hybrid photonic-plasmonic cavities can be tailored to display high Q factors and extremely small mode volumes simultaneously, which ultimately results in large values of the Purcell factor. Amongst the different hybrid configurations, those based on a nanoparticle-on-a-mirror plasmonic cavity provide one of the lowest mode volumes, though so far their operation has been constrained to wavelengths below 1 ¿m. Here, we propose a hybrid configuration consisting of a silicon photonic crystal cavity with a slot at its center in which a gold nanoparticle is introduced. This hybrid system operates at telecom wavelengths and provides high Q-factor values and small normalized mode volumes, leading to extremely large Purcell-factor values. The proposed cavity could be used in different applications such as molecular optomechanics, bio- and chemosensing, efficient quantum emitters, or enhanced Raman spectroscopy in the relevant telecom-wavelength regime.