Enhancing the Purcell Factor at Telecom Wavelengths by means of a Photonic-Plasmonic Hybrid Cavity

Hybrid cavities that combine photonic and plasmonic elements can be customized to exhibit both high Q factors and extremely small mode volumes, leading to significant increases in the Purcell factor ($F_{\mathrm{P}}$). In this work, we propose a hybrid system consisting of a silicon photonic crystal cavity with a slot at its center where a gold nanoparticle is located. We demonstrate large Purcell factors ($F_{\mathrm{P}}\approx10^{7}-10^{S}$) in the telecom spectral region. The presented results can find applications in molecular optomechanics, sensing, or enhanced Raman spectroscopy.