A wavelength demultiplexer based on waveguide broadening in silicon-on-insulator platform

Abstract

We propose a modified arrayed waveguide grating (AWG) demultiplexer formed by an array of parallel ridge waveguides of equal length fabricated in silicon-on-insulator (SOI). Each waveguide contains two sections with different widths. The lenghts of the two sections are modified from a waveguide to the adjacent waveguide, resulting in a wavelength dispersive phase array. With an appropiate demultiplexer output geometry, the light is focussed in the output slab waveguide combiner. The focal position is wavelength, dependent in the transverse direction, so that the optical signal is demultiplexed into separated output channels corresponding to different spectral bands. This device does not require bending waveguide sections which are essential in a conventional AWG demultiplexer, yielding very compact devices with potentially low loss. Numerical simulations have, been carried out to evaluate the influence of waveguide parameters such as lengths and widths of different waveguide sections on demultiplexer performance.