2 x 2 optical waveguide switch with bow-tie electrode based on carrier-injection total internal reflection in SiGe alloy

Based on the total internal reflection and the plasma dispersion effect of SiGe alloy, a 2 x 2 intersectional rib optical waveguide switch with bow-ti e electrode has been proposed and fabricated for the wavelength of 1.3-mum operation. The thickness of SiGe layer is 2.6 mum and the width is 9 mum. T he branch angle of the switch is 2 degrees and the bow-tie angle is 1.5 deg rees. The on-state crosstalk is -19.6 dB, the off-state extinction ratio is 38.5 dB and the off-state insertion loss is less than 1.70 dB, The switchi ng time is about 180 ns.