Multichannel Polarization-Controllable Superpositions of Orbital Angular Momentum States

Superposition of orbital angular momentum (OAM) states has attracted considerable attention due to its application in diverse scientific areas, such as high-capacity optical communication, kinematic sensing, spin object detection, quantum memory, and generation of rotational states in Bose-Einstein condensation. For practical applications of OAM states, a simple approach to generate OAM beams and manipulate OAM superpositions in multiple channels at will is highly desirable. Here, we propose and experimentally demonstrate a facile metasurface approach to realize polarization-controllable multichannel superpositions of OAM states at will. Multiple OAM beams in separate channels are generated by a single metasurface for an incident Gaussian beam with circular polarization. By manipulating the polarization state of the incident light, arbitrary control of the superpositions of various OAM states in multiple channels is realized. This approach provides a fast and efficient way for the manipulation of OAM superposition and significantly simplifies the experiment setup, which is of great importance for the current efforts in the fields of quantum entanglement, metrology, and optical data storage.