A Robust Basis for Multi-Bit Optical Communication with Vectorial Light

Abstract

Increasing the information capacity of communication channels is a pressing need, driven by growing data demands and the consequent impending data crunch with existing modulation schemes. In this regard, mode division multiplexing (MDM), where spatial modes of light form the encoding basis, has enormous potential but is impeded by noise due to imperfect channels. Here, this challenge is overcome by breaking the existing MDM paradigm of using the modes themselves as a discrete basis and instead exploiting the polarization inhomogeneity (vectorness) of vectorial light as the information carrier. It is shown that this vectorness communication basis is completely impervious to channel noise, which is verified by near perfect data fidelity maintained in multi-bit information transfer through atmospheric turbulence, with negligible changes on the order of 1%. This allows for demonstration of a new state-of-the-art of 50 vectorial modes in a communications channel with little cross-talk. This approach replaces conventional amplitude modulation with a novel modal alternative for potentially orders of magnitude channel information enhancement, offering a new paradigm to exploiting the spatial mode basis for optical communication.