Integrated Orbital Angular Momentum Emitters Based on Silicon Nitride Photonic Platform

Integrated orbital angular momentum emitters have been studied widely in the past few years. Meanwhile, silicon nitride (SiN
_x
) material provides a veritable platform for on-chip compact photonic integrated circuit. In this paper, we demonstrate integrated orbital angular momentum (OAM) emitters based on silicon nitride micro-ring resonators with angular gratings. By changing waveguide dimensions and duty cycle of gratings, several OAM emitters have been designed and fabricated. The relative high average emission efficiency was measured to be ( 13±1.2) %. The near and far-field fields of emitted OAM modes have excellent angular distributions. Therefore, the SiN
_x
material raises the prospect of practical and flexible platform for on-chip integrated OAM devices that offers excellent performance and high reliability.