Design and optimization of bright magnetic optical sources

The design of nanoresonators which modify the local density of states to enhance the magnetic Purcell effect while suppressing the electric Purcell effect is investigated. Quasinormal modes are used in place of the usual real frequency simulations to predict Purcell enhancements and to optimize multiple nanoresonator dimensions around the magnetic transition dipole of $\mathrm{Eu}^{3+}$ resulting in bright magnetic emitters. The use of QNMs allows the optimization of the particles to be carried out in terms of fundamental physical parameters such as the quality factor and mode frequency while also being significantly more computationally efficient than real frequency simulations.