ABSTRACT
This chapter shows that solitons and other special solutions of soliton equations play important roles in helping people understand the transverse structure of optical beams in optical cavities, the longitudinal structure of pulses in resonant media, superfluorescence, and the production of the Stokes wave in Raman scattering processes. It describes the fundamental ingredients required for laser operation. The chapter introduces the simplest model of a laser involving a medium of two-level atoms. It discusses the manifestation of optical bistability in ring and Fabry–Perot cavities. The chapter also discusses the stability of the "stable" solutions and find that they can undergo a series of period-doubling bifurcations leading to a temporally chaotic output. It looks at the remarkable behavior of a pulse propagating through an almost perfectly tuned resonant and initially passive medium. The resonator is tuned to support frequencies close to that of the laser transition.
