Criteria for Selection of Graded Index Filter Materials Based on an Analysis of Wave Propagation in a Periodic Medium

摘要

This report includes a survey of the factors affecting the performance of a filter. Although specifically directed at optical filters, most of the discussion is quite general, applying to the propagation of any wave in a medium with a spatially modulated response or susceptance. The intent of this work is to examine the factors affecting filter performance with a view toward perfecting filter design, to gain a deeper understanding of the relationship between rugate index profile parameters and the consequent optical properties, and to guide rugate deposition experiments. A wide range of systems which are usually treated as unique share important features with optical filters. Examples are acoustic filters, electronic energy bands in solid, lattice dynamics, transmission line theory, and waveguide theory. This report begins to lay the groundwork for development of an optimum transfer function and to determine the appropriate values for the filter parameters. Keywords include: Optical filter, Rugate, Spatially Modulated response, Chalcogenides, Halides, Oxides, Dielectric constant, Raleigh scattering, and Wave propagation.