Waveguide Surface Coherent anti-Stokes Raman Scattering Spectroscopy and optical second harmonic generation spectroscopy of molecules adsorbed on metal oxide surfaces

This dissertation reports the application of nonlinear optical effects for the investigation of vibrational and electronic spectroscopy of molecules adsorbed on thin film metal oxide surfaces and metal oxide surfaces. The main emphasis of the experiments cited here is to introduce the recently developed multi-photon technique, Waveguide Surface Coherent anti-Stokes Raman Scattering Spectroscopy (WSCARS), to the scientific community. Planar optical waveguides have been utilized to generate large optical field enhancements on metal oxide surfaces. Guided waves have been employed to obtain the surface coherent anti-Stokes Raman scattering spectra of pyridine, phenol, benzene, methanol, CD;Electronic spectra of surface bound species have been examined by resonantly enhanced surface second harmonic generation (SSHG). SHG spectra of trans-cinnamic acid adsorbed on optically cleaned fused silica have been obtained at room temperature and at 4 K. Surface second harmonic generation has been applied to study the adsorption of water and acetone onto thermally grown silicon dioxide/silicon surface. SSHG has been successfully applied to monitor photo-oxidation and photo-reduction of a rutile (110) surface.;Experiments are described, data are presented, and surface-adsorbate binding modes are discussed.