Linear and Nonlinear Optical Investigation of Films: I. Formalism for Time Resolved Multiphoton Process. I. Detection of Solid Water Phase Transitions on Silicon - Dioxide. III. Wave Guided Cars Spectroscopy.

Nonlinear optical processes can be described as multiphoton scattering events in terms of high order perturbation theory. The standard procedure for quantitative calculation of high order terms is to impose a steady state condition on the perturbative radiation fields. In the present work, this condition will be lifted, and explicit time dependencies in terms of pulsed radiation will be examined at length. Enhanced Linear and nonlinear scattering of laser radiation from a cryogenic Si-SiO_2 surface in the presence of H_2O vapor reveals the influence of the irreversible structural phase changes of solid water on and within the oxide layer of Silicon. Coherent Anti-Stokes Raman Scattering (CARS) is a four-photon process which, when conducted within the boundary conditions of a waveguiding medium, can serve as an enhanced surface and bulk probe.