High quality factor multi-layer symmetric hybrid plasmonic microresonator for sensing applications

A multi-layer symmetric hybrid plasmonic microresonator with two high-index dielectric microrings symmetrically near the metallic structure is proposed. Benefiting from introducing two dielectric rings near the metal, the multi-layer hybrid plasmonic microresonator has a high quality factor about 10,000, while still capable of retaining a small mode volume around 1.27μm3. As a potential application, the symmetric hybrid microresonator with air-filled gap regions could be used for sensing with a sensitivity high of 210 nm per refraction index unit, a large figure of merit of 1319 due to the high quality factor.