Optical waveguide characterization of dielectric films deposited by reactive low-voltage ion plating

We determine the quality of single films of various oxides, which are deposited on thermally oxidized silicon wafers by reactive low-voltage ion plating (RLVIP), by measuring their optical waveguide losses. We use a prism coupler for inserting the radiation of a wavelength-selectable He-Ne laser into the waveguide and a CCD camera for imaging the light scattered from the surface of the films. The waveguide losses of the RLVIP films are typically of the order of 1 to 10 dB/cm. Some data obtained for TiO(2) layers on thermally grown SiO(2) and RLVIP SiO(2) seem to confirm the presence of an absorbing boundary layer between RLVIP SiO(2) and TiO(2) that has been found in SiO(2)-TiO(2) multilayers. The waveguide measurements also reveal unusual index gradients in thick (~ 10 µm) single layers of Al(2)O(3) derived from multimode effective index calculations.