Single-Mode Fiber Optics

Prinicples and Applications, Second Edition,

Jeunhomme, Luc B. Jeunhomme

• Publisher: Routledge
• Year: 2019
• Print ISBN: 9780824781705
• eBook ISBN: 9781351416443
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

A basic, unified reference, rather than a description of the current experimental activity, presenting the scientific and engineering principles of single-mode optical fibers. It does, however, update discussions to reflect developments since the 1983 first edition, particularly those on international standards for fibres and measurement procedures, improvements in fibre attenuation control, fibre gyrometry, high-birefringence fibres, dispersion shifted and dispersion flattened fibres, connectors and splicing equipment, long distance terrestrial and undersea communication systems, and long distance transmissions systems.

1
Basic Theory

1.1 Introduction

This chapter is devoted to an extended view of the theory of light propagation in single-mode fibers. However, before treating the case of the circular core single-mode fiber, for which the physical meaning of the results is somewhat obscured by the mathematics involved, we discuss in this section the general guiding properties of the dielectric slab waveguide. This case involves much less complicated equations and allows a better physical discussion of the main features of the modes, which are qualitatively similar to those of the circular core fiber. This section can thus be seen as an introduction to the electromagnetic formalism used in the remainder of the chapter, for readers not familiar with the modes of dielectric circular waveguides.

Readers already familiar with the theory of dielectric waveguides may jump directly to Sec. 1.2, which is devoted to a detailed study of the first two modes of ideal step-index fibers. In Sec. 1.3 graded-index single-mode fibers are treated in terms of equivalent step-index fibers after exact theories have been reviewed. Finally, fibers with cladding refractive index variations are studied in Sec. 1.4. This chapter thus provides all the necessary material for the study of the transmission characteristics of various single-mode fibers in subsequent chapters.

1.1.1 Modes of the Symmetric Dielectric Slab Waveguide

A typical example of a symmetric dielectric slab waveguide is shown in Fig. 1.1. It consists of a sheet of material with refractive index n₁ and thickness 2a, sandwiched between two infinite layers of material with refractive index n₂ lower than n₁. In the following we assume that the structure is unlimited in the y and z directions, and that the materials are isotropic and without loss (permittivities are real and scalar). We write the electric (resp. magnetic) field of a purely monochromatic wave propagating in the z direction as

E¯(resp. H¯)(x, y, z)=E¯(resp. H¯)(x) exp[i(ωt−βz)](1.1)

FIGURE 1.1 Example of a dielectric slab waveguide consisting of a sheet of material with refractive index n₁ and thickness 2a between two layers of material with refractive index n₂ lower than n₁.

where ω to is the optical pulsation, β the propagation constant of the wave, and (x, y, z) the usual cartesian coordinates shown in Fig. 1.1. There is no y dependence of the fields on the right-hand side of...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Contents
• About the Series
• Preface
• 1 Basic Theory
• 2 Birefringence Properties
• 3 Attenuation
• 4 Signal Distortion
• 5 Characterization
• 6 Passive Components
• 7 Telecommunication Applications
• 8 Sensor Applications
• 9 Nonlinear Optical Effects
• List of Symbols
• Index