Effect of vortex order on helical-phased donut mode launch in multimode fiber

Abstract

Optical fiber sensors based on mode division multiplexing (MDM) play an increasingly vital role for real-time multi-parameter measurements. For multimode fibers, the central core region typically has defects in the refractive index profile, thus limiting the stability of lower-order modes for MDM. To avoid the central core region, this paper introduces a new launch based on helical-phased ring modes in multimode fiber using a verticalcavity surface-emitting laser (VCSEL) array and a vortex lens. A data rate of 14 Gbit/s for a multimode fiber length of 1200 meters is achieved at a wavelength of 1550.12 nm. The transverse electric field, power coupling coefficients and eye diagrams are analyzed.