Nonlinear Fiber Optics for Bio-Imaging by Roque Gagliano Molla Ingeniero Electricista Universidad de la República, Montevideo, Uruguay, 2001 Submitted to the Department of Electrical Engineering and Computer Science and the faculty of the Graduate School of the University of Kansas in partial fulfillment of the requirements for the degree of Master of Science. Chair: Dr. Rongqing Hui Dr. Victor Frost Dr. Kenneth Demarest Date of Thesis Defense: May 20th, 2005Acknowledgements I would like to show my appreciation and gratitude to my advisor Dr. Rongqing Hui. This has been an amusing and rewarding learning experience that we started by putting some living cells in a Pyrex back in January 2004. I would like to thank him not only for his advice and financial support but also for being an endless source of optimism and an example of self-motivation. I would also like to thank the rest of my committee, Dr. Victor Frost and Dr. Kenneth Demarest. Special thanks to Jay Unruh and the rest of the group at Dr. Carey Johnson’s laboratory of the Chemistry Department at the University of Kansas where all the experiments of this work were performed. Also, I would like to acknowledge the Fulbright Program, the OAS-LASPAU Program, the Barca Family and the KU International Program for their support. Finally I would like to thank my family and friend for helping me removing all the obstacles in order to make my dream of a graduate education possible. iiTable of Contents Acknowledgements...........................................................................................................ii Table of Contents.............................................................................................................iii List of Figures..................................................................................................................vi Abstract..........................................................................................................................viii Chapter 1: Introduction............................................................................................... 1 1.1 Motivation......................................................................................................... 1 1.2 Two-photon microscopy and wavelength-tunable pulsed laser sources........... 1 1.3 Organization...................................................................................................... 4 Chapter 2: Nonlinear Effects of Optical Fibers .......................................................... 5 2.1 General Analysis............................................................................................... 5 2.2 Nonlinear Pulse Propagation............................................................................. 7 2.3 Chromatic Dispersion ..................................................................................... 10 2.4 Nonlinear effects............................................................................................. 11 2.4.1 Self Phase Modulation (SPM) ................................................................ 11 2.4.2 Cross Phase Modulation (XPM) ............................................................. 12 2.4.3 Four Wave Mixing (FWM)..................................................................... 12 2.4.4 Stimulated Raman Scattering (SRS)....................................................... 13 2.4.5 Stimulated Brillouin Scattering (SBS).................................................... 15 2.5 Split Step Fourier Method............................................................................... 15 Chapter 3: Optical Solitons....................................................................................... 17 3.1 Solitons in Physics .......................................................................................... 17 3.2 Fiber Solitons.................................................................................................. 18 3.3 Fundamental Soliton ....................................................................................... 20 3.4 Higher Order Solitons..................................................................................... 20 3.5 Soliton Interaction........................................................................................... 20 3.6 Loss-Managed Solitons................................................................................... 21 3.7 Dispersion Management Solitons (Average Solitons).................................... 22 Chapter 4: Short Pulsed Fiber Lasers ....................................................................... 24 iii4.1 Short Pulsed Cavity Lasers ............................................................................. 24 4.2 Mode-locking.................................................................................................. 25 4.2.1 Active Mode-locking .............................................................................. 26 4.2.2 Passive Mode Locking............................................................................ 26 4.3 Solid State Laser ............................................................................................. 27 4.4 Fiber Lasers..................................................................................................... 29 4.4.1 Ring Cavity Fiber Lasers ........................................................................ 30 4.4.2 Fabry-Perot or Linear cavities ................................................................ 32 4.5 High Power Pulsed Fiber Lasers..................................................................... 33 Chapter 5: Photonic Crystal Fibers........................................................................... 35 5.1 Fundamentals of photonic crystal waveguiding ............................................. 35 5.2 Classification of PCF ...................................................................................... 36 5.3 Modelling of microstructured fibers ............................................................... 37 5.4 Fabrication of photonic crystal fibers ............................................................. 39 5.5 Applications .................................................................................................... 40 Chapter 6: Experimental and Numerical Analysis of Soliton Self-Frequency Shift 42 6.1 Experimental Results