Misalignment Tolerance of Orbital Angular Momentum Modes for Mode Group Division Multiplexing in Conventional Multimode Fibers

Abstract

Mode group division multiplexing, a subgroup of space division multiplexing, is one of the promising techniques for increasing the transmission capacity of multimode fibers (MMFs). In this context researchers have shown a lot of interest in orbital angular momentum modes, particularly in MMFs. This paper studies misalignment tolerances of the orbital angular momentum modes when used for mode group division multiplexing in conventional MMFs. This is one of the limiting factors in increasing the number of mode groups. We show that the alignment tolerance progressively decreases from 3.6 µm to 1.3 µm as we go from principal mode group number 1 to 8.