Generation of Vectorial Vortex Beams with Switchable Radial and Azimuthal Polarizations

Abstract

In this work, we designed and experimentally demonstrated a silicon nitride microring resonator on top of which angular array of holes acting as grating elements are embedded to generate vectorial vortex beams. Such grating structure is fabricated during a simple reactive-ion etch process induced by lag-effect. The device is capable of generating broad-band radially and azimuthally polarized vortex beams by switching the polarization and wavelength of the excited WGMs.