Accession Number : ADA115713

Title :   Study of the Effects of Surface Roughness and Ti Diffusion on In-Plane Scattering in Ti-LiNbO sub 3 Waveguides.

Descriptive Note : Final rept. 20 Sep 80-19 Nov 81,


Personal Author(s) : Vahey,David W ; Busch,James R

PDF Url : ADA115713

Report Date : 31 Mar 1982

Pagination or Media Count : 102

Abstract : The primary objective of this program has been to understand and subsequently reduce the sources of scattering in planar Ti-diffused LiNbO3 waveguides. On the basis of previous work these were perceived to be surface roughness and surface index inhomogeneities associated with Li-/ti-O compound formation during diffusion. A secondary objective has been to characterize state-of-the-art waveguides to determine their potential for use in an integrated optical spectrum analyzer providing at least 40 dB dynamic range at the fourth off-axis pixel. A key ingredient to meeting these objectives was found to be the accurate determination of waveguide scattering parameters from in-plane scattering measurements. These were frustrated by superimposed background scattering associated with input and output coupling. Both prism and end-fire techniques were used. A statistical analysis employed to effectively subtract the background contribution provided this best estimate: Existing waveguides provide the 40 dB dynamic range at the fourth pixel that is marginally acceptable for the spectrum analyzer application; however, a +or=5 dB uncertainty in dynamic range is within one standard deviation of our average value. In the case of 35 dB dynamic range at the fourth pixel, consistent with this uncertainty, an analysis of dynamic range versus pixel number is used to show that 40 dB dynamic range is still achieved at the tenth off-axis pixel.

Descriptors :   *Waveguides, *Scattering, *Surface roughness, *Background, Diffusion, Optical properties, Output, Spectrum analyzers, Statistical analysis, Standard deviation, Parameters, Surfaces, Indexes, Dynamic range, Integrated systems, Optics

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE