Chapter 2 Femtosecond pulses in optical fibers

Abstract

Publisher Summary This chapter discusses the femtosecond pulses in optical fibers. The chapter presents observation, manipulation and control of femtosecond pulses. The nomenclature and quantities in use are overviewed. The chapter illustrates the diagnostic techniques for ultrafast pulses and the application of some of these to ultrafast pulse propagation in optical fibers. Experimental results that reveal the behavior of the electric field through the temporal phase function of the pulse are illustrated, and a variety of nonlinear effects ranging from soliton formation, dark soliton formation, pulse breakup, intrapulse Raman scattering to soliton self-frequency shifts are presented. Fourier pulse-shaping is introduced along with a variety of programmable modulator techniques, and some examples of shaped pulses are presented. The application of pulse shaping to propagation in optical fibers is illustrated. The addition of feedback to the pulse-shaping capacity is described illustrating the adaptive control methods based on genetic algorithms showing that undistorted pulse propagation can be obtained by suitable preshaping of the input pulse launched in the fiber. The chapter discusses the propagation of femtosecond pulses in photonic crystal fibers, illustrating some results on the enhanced nonlinear effects, self-frequency shifting, high-order soliton formation and other aspects such as selective harmonic generation.