Methods and technique of manufacturing silica graded-index fibers with a large central defect of the refractive index profile for fiber-optic sensors based on few-mode effects

This work presents an alternative fast and simple method for the design of a refractive index profile of silica multimode optical fibers (MMFs) with extremely enlarged core diameters of up to 100 µm for laser-based multi-gigabit short-range optical networks. We demonstrate some results of 100 µm core MMF graded index profile optimization performed by a proposed solution, which provides a selected mode staff differential mode delay (DMD) reduction over the “O”-band under particular launching conditions. Earlier on, a developed alternative model for a piecewise regular multimode fiber optic link operating in a few-mode regime for the computation of laser-excited optical pulse dynamics during its propagation over an irregular silica graded-index MMF with an extremely large core diameter, is utilized to estimate the potentiality of fiber optic links with the described MMFs. Here, we also present the comparison results of the simulation of 10GBase-LX optical signal transmission over 100 µm core MMFs with conventional and optimized graded-index refractive index profiles.

Download Full-text

Utilizing multimode interference effects in integrated graded-index optical waveguides for efficient power splitting

COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ◽

10.1108/compel-09-2017-0374 ◽

2018 ◽

Vol 37 (4) ◽

pp. 1556-1563 ◽

Cited By ~ 4

Author(s):

Jan-Philipp Roth ◽

Thomas Kühler ◽

Elmar Griese

Keyword(s):

Refractive Index ◽

Ion Exchange ◽

Refractive Index Profile ◽

Multimode Interference ◽

Power Splitting ◽

Index Profile ◽

Content Type ◽

Graded Index ◽

Waveguide Components ◽

Efficient Power

Purpose For the realization of optical waveguide components, needed for photonic integrated circuits, multimode-interference based (MMI-based) devices are an excellent component class for the realization of low loss optical splitters. A promising approach to the manufacturing of these components is their embedding in thin glass sheets by ion-exchange diffusion processes, which has not yet been extensively studied. This study aims to significantly enhance the modeling of the diffusion process to support manufacturing of graded-index, MMI-based optical splitters. Design/methodology/approach The methods of design and analysis of MMI-based components are based on a step-index refractive index profile. In this work, fundamental correlations between the properties of the manufacturing ion-exchange process and the characteristics of the graded-index, MMI-based components are established. The refractive index profile is calculated with a proprietary solver based on the finite element method. Any further investigation with respect to parameter influence is based on the beam propagation method, specifically a finite difference based, semi-vectorial, wide-angle beam propagation algorithm. The influence of the parameters of the self-imaging effect is investigated. On this basis, different approaches for efficient power splitting with graded-index, MMI-based waveguide components are evaluated. Findings Easy approximations – mostly linear – can be found to model the dependencies of the investigated parameters. The resulting graded-index splitters are characterized by their low excess and insertion loss. Originality/value These findings are the first step in the direction of the semi-analytical modeling of the respective waveguide components to reduce the numerical effort.

Download Full-text