Orbital Angular Momentum Communications in Commercial Multimode Fiber with Strong Mode Coupling
Fengchao Ni, Zhengyang Mao, Haigang Liu, Xianfeng Chen
Abstract
The optical orbital angular momentum (OAM) is regarded as a new dimension for next-generation communication systems for its potential to break the Shannon limit of communication capacity. However, since OAM modes cannot be stably transmitted in conventional fibers, all of the OAM communication schemes proposed so far primarily utilize specialty fibers or multimode fiber (MMF) with weak mode coupling to transmit OAM modes, which hinders the widespread application of OAM communication. Here, we demonstrate the OAM communication in commercial MMF with strong mode coupling by utilizing the transmission matrix (TM) method, for the first time as far as we know. After measuring the TM of MMF, we first experimentally realize the demultiplexing of up to 5 superimposed OAM modes after transmission over MMF with high separation accuracy. Then, the validation of our scheme is further verified by demonstrating dual-channel OAM shift keying and OAM division multiplexing communication in commercial MMF experimentally. This new method exhibits a huge potential for implementing high-capacity and low-crosstalk OAM communication in conventional MMF, which opens a path toward commercial OAM fiber communication and inspires more applications of OAM in commercial MMF.