Properties of High Energy Laser Transmission through Optical Fibers
High energy laser transmission through large core optic cables
By christopher Kennedy
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in CREOL – College of Optics and Photonics at the University of Central Florida
Orlando, Florida
Summer Term
2013
Major Professors: Michael Bass
©2013 Christopher Kennedy
ABSTRACT
ACKNOWLEGEMENTS
TABLE OF CONTENTS
LIST OF FIGURES
LIST OF TABLES
LIST OF ACRONYMS/ABBREVIATIONS
1. INTRODUCTION
1.1 Research Motivation
Laser induced damage is of interest in studying the transmission of large amounts of optical energy through step-index, large core multimode fibers. Optical fibers often have to be routed around objects when laser light is being transmitted between two locations which require the fiber to bend into a curve. Depending on how tight the bend is, this can result in transmission losses or even catastrophic damage when the energy density of the laser pulse exceeds the damage threshold of silica glass.
Waveguide theory predicts that light travelling through a bend will form whispering-gallery modes that propagate through total internal reflection bounces along the inside of the outer edge of the bend. This is critical since in these locations the energy density of the light will increase significantly, raising the potential of laser damage, nonlinear effects, and transmission losses. This loss is especially problematic when two 90° bends going in opposite directions are in close proximity of each other, forming an ‘S-bend’. Light that is grouped along the outer edge going through the first bend will enter the second bend at a sharper angle
By christopher Kennedy
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in CREOL – College of Optics and Photonics at the University of Central Florida
Orlando, Florida
Summer Term
2013
Major Professors: Michael Bass
©2013 Christopher Kennedy
ABSTRACT
ACKNOWLEGEMENTS
TABLE OF CONTENTS
LIST OF FIGURES
LIST OF TABLES
LIST OF ACRONYMS/ABBREVIATIONS
1. INTRODUCTION
1.1 Research Motivation
Laser induced damage is of interest in studying the transmission of large amounts of optical energy through step-index, large core multimode fibers. Optical fibers often have to be routed around objects when laser light is being transmitted between two locations which require the fiber to bend into a curve. Depending on how tight the bend is, this can result in transmission losses or even catastrophic damage when the energy density of the laser pulse exceeds the damage threshold of silica glass.
Waveguide theory predicts that light travelling through a bend will form whispering-gallery modes that propagate through total internal reflection bounces along the inside of the outer edge of the bend. This is critical since in these locations the energy density of the light will increase significantly, raising the potential of laser damage, nonlinear effects, and transmission losses. This loss is especially problematic when two 90° bends going in opposite directions are in close proximity of each other, forming an ‘S-bend’. Light that is grouped along the outer edge going through the first bend will enter the second bend at a sharper angle
References: 11) G. H. Spencer and M. V. R.K. Murty (1962). "General ray tracing Procedure" (PDF). J. Opt. Soc. Am. 52 (6): 672–678. doi:10.1364/JOSA.52.000672. 20) P. N. Butcher, D. Cotter, The Elements of Nonlinear Optics, Digital ed. Cambridge, UK: Cambridge University Press, 2003.