Silica-based low loss and high extinction ratio 8/spl times/8 thermo-optic matrix switch with path-independent loss arrangement using double Mach-Zehnder interferometer switching units

We describe a low loss and high-extinction ratio 8/spl times/8 thermo-optic matrix switch with a reduced 8 stage configuration composed of silica-based planar lightwave circuits. The average insertion loss and the extinction ratio were 5.1 dB and 60.3 dB, respectively.