4 × 4 InAlGaAs/InAlAs optical switch fabric by cascading Mach-Zehnder interferometer-type optical switches with low-power and low-polarization-dependent operation

High-speed optical switches are essential devices to construct next generation optical networks. We have studied on 2 × 2 Mach-Zehnder interferometer-type optical switches and demonstrated low-polarization-dependent switching operation with crosstalks of less than −20 dB and injection currents of about 5 mA, and response times of about 3 nanoseconds. In this work, our conventional 2 × 2 switch was extended to a 4 × 4 optical switch fabric by cascading approach. As a result, fundamental switching operation was confirmed with low power and low-polarization dependence.