640-Gbit/s Data Transmission and Clock Recovery Using an Ultrafast Periodically Poled Lithium Niobate Device

This paper presents the first demonstration of the use of a periodically poled lithium niobate device for signal processing at 640 Gbit/s. Clock recovery is performed successfully using the lithium niobate device, and the clock signal is used to control a nonlinear fiber-based demultiplexer. The full 640-Gbit/s system gives error-free performance with no pattern dependence and there is less than 1-dB power penalty after 50-km fiber transmission.