Abstract:
This thesis describes research on parametric processes in photonic crystal fibers and dispersion-shifted fibers. The research programme encompassed a study of optical parametric generation and the modeling of this process. These studies have culminated in the development of fiber optical parametric oscillators based on photonic crystal fibers and dispersion-shifted fibers. These oscillators generate widely tunable coherent radiation in the visible and infrared regions of the electromagnetic spectrum. These studies have shown that the frequency shift of the parametric sidebands depend strongly on the detuning of the pump from the fiber's zero dispersion wavelength. In the absence of walk-off it is found that fluctuations in the refractive index profile of the fiber along its length provide the ultimate limit to the tuning range. In addition, it is shown that tunable optical parametric generation can be used as a tool for measuring chromatic dispersion in photonic crystal fibers, as well as in conventional optical fibers. A simple analytical model for the dispersive properties of photonic crystal fibers has been developed, and its accuracy has been verified by a full numerical simulation. The combined effect of Raman and parametric gain on single-pump optical parametric amplifier has also been studied. The real part of the Raman susceptibility is shown to have a strong influence on the phase-matched parametric gain.
