Analysis and design of optical filters consisting of dielectric grating waveguides

The propagation characteristics of dielectric grating waveguides are analyzed, using a rigorous modal theory. It is shown that the structures behave like transmission or reflection filters within a small range of some given parameters. Approximate expressions are also presented for the prediction of their characteristics and they are valuable for the design of these structures. It is also shown that the linewidths at the frequencies of maximum reflection or transmission may be conveniently adjusted by varying the design parameters. Finally, a discussion is presented on how to use these filters in some optical devices.