An important recent development in linear wave physics is the discovery by M.V. Berry of Bristol Univesity, England, of an unexpected phase shift in the adiabatic limit for the Schroedinger equation. This phase is acquired upon adiabatic transport of a quantum system around a closed circuit in the parameter space of the Hamiltonian, and is solely a topological property of the circuit. These ideas have recently been extended by Professor Chiao to the field of optics. An experiment in linear optics has shown that this phase appears as the angle of optical rotation of linear polarization of light in a helically wound optical fiber. The current research extends these investigations both theoretically and experimentally to nonlinear wave propagation, with emphasis on the propagation of linearly polarized optical solitons generated by picosecond pulses inside a helical fiber. The question of how Berry's phase extends to the nonlinear case will thereby be partly answered. Potential applications of this new fundamental phenomenon will be explored.
