Picosecond Optical Switching Using RF Nonlinear Transmission Lines

We propose a novel sub-ps optical switch composed of an interferometer in which the phase difference between the arms is controlled by a pair of electrooptic modulators (EOMs) driven by integrated nonlinear transmission lines (NLTLs). As a proof-of-concept we demonstrate 70 ps switching using discrete LiNbO₃ traveling wave EOMs and commercially available NLTLs capable of delivering a 35 ps falling edge. This technique is simple and robust, and can potentially be extended to sub-ps switching by integrating the NLTL into the EOM waveguide. This fast switch can be used to implement an Optical Time Division Multiplexing (OTDM) network architecture.