Demonstration of pulse frequency division multiplexing using terahertz optical asymmetric demultiplexer

A new method of pulse frequency division multiplexing (PFDM) to increase the capacity of local fiber-optic communications networks heavily relies on optical signal processing using an all-optical AND gate. In this work, we report a conceptual demonstration of the PFDM method using a terahertz optical asymmetric demultiplexer as a fast (picosecond switching time), low switching energy (as low as 125 fJ) optical AND gate for the optical signal processing. This creates a real possibility for the practical realization of the PFDM method.