All-optical binary counter promises optical switching

The growth of high-speed optical networks is driving demand for replacing electronic components with all-optical devices. Researchers at BT Adastral Park (Ipswich, England) and Aston University (Birmingham, England) built an all-optical binary counter consisting of four all-optical switching gates based on semiconductor optical amplifiers (SOAs). Such a binary counter, operating at the bit level, could perform several functions, including packet regeneration, parity checking, network-performance verification, header extraction, and payload processing.

In their proof-of-principal experiment, the researchers built the counter using two optical regenerative memories. Each memory was based on two SOA-based all-optical switching gates, one for wavelength conversion and one to act as an AND/OR gate. The system was designed so that optical pulses would cause the gate to output either a zero or a one, depending upon the time it took the pulse to travel the system. The device should be capable of gate-switching speeds of approximately 100 Gbit/s, the researchers said. They predicted that further research would allow them to build a less-complex device. Contact Keith Blow at [email protected].