Silicon-on-insulator eight-channel optical mulltiplexer based on a cascade of asymmetric Mach-Zehnder interferometers

A monolithically integrated eight-channel optical multiplexer (Mux) with a 400 GHz channel spacing similar to 1550 nm is presented based on a silicon-on-insulator rib waveguide and an asymmetric Mach-Zehnder interferometer. All channels were optimized independently with integrated heaters. The fully tuned Mux shows an adjacent channel isolation of similar to 13 dB, an excess loss of similar to 2.6 dB, and a channel uniformity of similar to 1.5 dB over a 25 nm wavelength span. In addition, the phase tuning efficiency for different interlevel dielectric layer thicknesses and thermal crosstalk were investigated. (c) 2008 Optical Society of America.