Magnetic and Electric Purcell Enhancement in a Hybrid Metal-Dielectric Nanostructure

Hybrid metal-dielectric structures combine the advantages of both metal and dielectric materials, enabling high-confined but low-loss magnetic and electric resonances through deliberate arrangements. However, their potential for enhancing magnetic emission has yet to be fully explored. Here, we study the magnetic and electric Purcell enhancement supported by a hybrid structure composed of a dielectric nanoring and a silver nanorod. This structure enables low Ohmic loss and highlyconfined field under the mode hybridization of magnetic resonances on a nanoring and electric resonances on a nanorod in the optical communication band. Thus, the 60-fold magnetic Purcell enhancement and 45-fold electric Purcell enhancement can be achieved. Over 90% of the radiation can be transmitted to the far field. For the sufficiently large Purcell enhancement,the position of emitter has a tolerance of several tens of nanometers, which brings convenience to experimental fabrications. Moreover, an array formed by this hybrid nanostructure can further enhance the magnetic Purcell factors.The system provides a feasible option to selectively excite magnetic and electric emission in integrated photonic circuits. It may also facilitate brighter magnetic emission sources and light-emitting metasurfaces with a more straightforward design.