Progress in integrated devices for optical vortex emission.

Optical vortices are the light beams with orbital angular momentum (OAM), helical phase fronts and azimuthal component of the wave vector. The demand for miniaturization and scalability requires avoiding shortcomings of bulk optics via photonic integration. The integrated OAM emitters are designed to generate and manipulate OAM beams. Photonic integration is compatible with high purity of single mode emission and high efficiency, achieving controllable mode superposition and multiplexing. The potential applications in microscopy, micromanipulation, telecommunications and quantum information are presented and reviewed. [ABSTRACT FROM AUTHOR]