Integrated photonic emitter with a wide switching range of orbital angular momentum modes

Due to the nature of infinite dimensionality, the orbital angular momentum (OAM) has been considered as a new degree of freedom of light and widely expanded the scopes of substantial optical applications such as optical telecommunication, quantum information, particle manipulation and imaging. In recent years, the integrated photonic OAM emitters have been actively investigated due to both compactness and tunability. Essentially, the number of available OAM modes by dynamic switching should be large enough so that the dimensionality of OAM could be explored as much as possible. In this work, an integrated photonic emitter with a wide switching range of OAM modes is theoretically developed, numerically simulated, and experimentally verified. The independence of the micro-ring cavity and the scattering unit provides the flexibility to design the device and optimize the performance. Specifically, the dynamic switching of nine OAM modes (l = -4 ~ 4) with azimuthal polarization has been demonstrated by electrically controlled thermo-optic effect.