Analysis of Finite Beam Contributions to Waveguide Wavelength Division Demultiplexer Design

Micrograting devices have recently been implemented in chalcogenide [1], polymer [2], GaAs [3], and InP [4] based materials for multichannel wavelength multiplexer/demultiplexer applications. In waveguide grating demultiplexers, the micrograting length/beam width ratio (q = d/ωo) is an important parameter in determining device performance. Finite beam Bragg diffraction effects have previously been considered in the case of thick planar gratings [5,6], but should also be accounted for in the design of waveguide demultiplexers, if beam profiles, efficiencies, and channel selectivities are to be optimized in such devices.