Reflection-type optical waveguide switch with bow-tie electrode

Based on the total internal reflection and the plasma dispersion effect of SiGe alloy, an intersectional rib optical waveguide switch with bow-tie electrode has been proposed and fabricated for operating wavelengths of 1.3 and 1.55 /spl mu/m. The thickness of the SiGe layer is 2.6 /spl mu/m and the width is 9 /spl mu/m. The branch angle of the switch is 2/spl deg/ and the bow-tie angle is 1.5/spl deg/. The crosstalks are -19.6 dB for 1.3 /spl mu/m and -21.8 dB for 1.55 /spl mu/m. At both wavelengths, the extinction ratio is larger than 38.5 dB and the insertion loss is less than 1.70 dB. The switching time is about 180 ns.