Vertical beaming of incoherent quantum emitters via the near-field coupling of Fano resonance

Abstract

We report highly collimated radiation from incoherent quantum emitters coupled to photonic dispersion-engineered structures. Two-dimensional free-standing photonic crystal slabs sustained an extremely high density of states for vertically leaky light at discrete frequencies, which results from the constructive interference between directly reflected light and quasi-bound guided modes, referred to as Fano resonance. Electromagnetic simulations showed that an electric dipole that is excited near a photonic crystal slab generates vertically directional radiation at every Fano resonance frequency. The radiation distribution of an electric dipole is strongly correlated with the angular reflectance of a coupled photonic crystal slab. The strategy developed herein will be useful to achieve a vertical beam from quantum emitters such as transition metal dichalcogenide monolayers, facilitating the delivery of light into other external optics.