Nonlinear phenomena in dipole-waveguide structures

Thesis (Ph. D.)--University of Rochester. Institute of Optics, 2002.When an oscillator is situated near a waveguide and such a system is driven in the nonlinear domain, interesting results can occur. For the situation in which the waveguide develops an intensity-dependent nonlinearity, the intrinsic linear properties of the oscillator, such as its radiative lifetime, are modified. Forcing the oscillator to move outside the regime of simple harmonic motion can result in unexpectedly strong harmonic fields. Theoretical results for the linear oscillator and the nonlinear waveguide are studied for an array of fundamental geometries. Intensity-induced lifetime changes of > 15% were found to be possible. Experimental results for the nonlinear oscillator and the linear waveguide are given for the case of a frequency-doubling nonlinearity. The structure was found to impart two orders of magnitude enhancement in the second-harmonic radiation the oscillators could produce. Variations of this geometry provide insight into the nature of the geometry such as mode-coupling effects and the precise mechanism for second-harmonic generation