168 Gbps error-free demultiplexing with hybrid-integrated symmetric Mach-Zehnder all-optical switch

摘要

All-optical switches are essential for various types of high-speed all-optical processing (demultiplexing, wavelength-converting, or regenerating) expected in future optical communications. Recently, the symmetric Mach-Zehnder (SMZ) all-optical switch [1] has attracted considerable attention as a promising approach to a practical level. The SMZ all-optical switch is based on a nonlinear phase shift induced by the carrier density change in a semiconductor, but its switching speed is not restricted by the carrier lifetime. In this switch, two nonlinear waveguides, one in each arm of the Mach-Zehnder interferometer, are excited with an appropriate time delay. This switching mechanism cancels out the effect of the slow relaxation of the utilized optical nonlinearity, and thus provides ultrafast switching with a nearly square window. We have demonstrated the ultrafast and highly efficient capabilities of the SMZ all-optical switch [2-3], and have predicted its applicability to all-optical processing at bit rates far beyond 100 Gbps. In this report, we describe the hybrid integration of the SMZ all-optical switch, and the error-free demultiplexing of 168 Gbps data pulses with this switch.