Few Mode Fiber Designs For Next Generation Communication Networks

Abstract

The importance of optical fiber and its research is growing exponentially, due to newlinethe variety of applications in this digital world. Starting from components, and sensors to newlinethe high data rate communication the demand for use is very high. Though different newlinetypes of optical fibers are there, for a long, the few-mode fiber (FMF) research is newlineregenerated due to its high data rate transmission ability. In this dissertation work, the newlinedesigns of FMFs are carried out with an update of material composition, and geometry to newlineestablish weakly coupled spatial division multiplexing (SDM)/ mode division newlinemultiplexing (MDM) links. Also, the machine learning technique is used with an inverse newlinemodeling approach to design FMFs with weak coupling optimization. newlineA new approach for designing FMFs by varying the material compositions of newlinecore and cladding to attain a maximum of ten modes with mode separation of greater newlinethan 1x10-3 is proposed in the first phase of the dissertation work. Two types of FMFs newlinenamely, gaussian core (G-FMF) and dual-core trench-assisted FMF (DC-TA-FMF) are newlineproposed with fused silica cladding and Germanium Oxide (GeO2) doped core. The newlinerelative index difference (and#916;) between core and cladding is maintained within a range of newline1% - 3% by varying the mole fraction of GeO2. This range of index difference allows newlineguiding a few ten linearly polarized (LP) modes under weakly guiding approximations newlinewith mode degeneracy. However, the other profile parameters are selected systematically newlinethrough simulation to maintain the mode count to ten with low mode coupling, low newlineDMGD, large effective mode area, low dispersion, and low bending loss. The proposed newlineG-FMF is used to establish a 10x10 Gbps SDM/MDM link over C+L-band through newlinesimulation to verify the usefulness of the proposed FMF for MDM application. The link newlinehas been extended over a length of 50 km without amplifiers with a loss of 0.2dB/km newlineusing intensity modulation and direct detection (IM-DD). The link performance is newlineanalyzed and measured through an acceptable bit-error rate (B