Thermooptical digital switch arrays in silica-on-silicon with defined zero-voltage state

Arrays of thermooptical digital switches for 1300 nm wavelength have been fabricated employing PECVD silica on silicon technology. The switches are based on mode sorting in asymmetric waveguide branches. An asymmetric layout of the waveguide branch/crossing leads to a defined zero-voltage state which is useful for protection switching in optical SDM-networks. The power consumption is reduced by heat flow optimization using silica and silicon microstructuring. The switch arrays are coupled to fiber ribbons.