Tunable wavelength-selection switch and multiplexer/demultiplexerbased on asymmetric silica-on-silicon Mach-Zehnder interferometer

Abstract

Wavelength multi/demultiplexers with 1 nm spacing have been realised with an asymmetric 2 × 2 Mach-Zehnder interferometer in silica-on-silicon. Heating one arm of the interferometer allows for wavelength tuning or wavelength switching of the outputs. Switching or tuning over 1 nm is achieved with only 95 mW within rise and fall times added to of 150 and 220 µs, respectively. Tuning and switching can be seperated, as temperature changes in the substrate also result in wavelength shifts.