Towards Polarization Routing of Magnetic and Electric Dipolar Emission with Dielectric Metasurfaces

Abstract: We investigate the polarization properties of emission associated with the magnetic dipole and electric dipole transitions of europium(III) coupled to an anisotropic dielectric metasurface with polarization-engineered electric and magnetic photonic local density of states. The metasurface consists of a square array of Mie-resonant elliptical a-Si:H dimers situated on an SiO$_2$ substrate and embedded in a PMMA film containing Eu(TTA)$_3$. Based on reciprocity principle, it was designed to achieve maximum electric (magnetic) field enhancement in the dimer gap at 610 nm (590 nm) for $x$-polarized ($y$-polarized) normally incident light in order to selectively enhance the electric dipole (magnetic dipole) emission into the $x$-polarized ($y$-polarized) emission channel, respectively. Momentum-resolved spectroscopy and back-focal plane imaging of emission of the fabricated light-emitting metasurface clearly reveal the intended polarization-dependent emission behaviour, with the $x$-polarized ($y$-polarized) emission showing a reduced (enhanced) ratio of the magnetic-/electric dipole emission intensity, correspondingly where the magnetic dipole emission is enhanced with a magnetic field enhancement from the nanostructures. The demonstrated polarization-dependent interaction of a designed nanostructure with the electric- and magnetic dipolar transitions of trivalent lanthanide ions opens an avenue towards routing of emission of different multipolar orders into different polarization channels.