Optical switch fabrics for ultra-high-capacity IP routers

Next-generation switches and routers may rely on optical switch fabrics to overcome scalability problems that arise in sizing traditional electrical backplanes into the terabit regime. In this paper, we present and discuss several optical switch fabric technologies. We describe a promising approach based on arrayed waveguide gratings and fast wavelength tuning and explain the challenges with respect to technical and commercial viability. Finally, we demonstrate an optical switch fabric capable of 1.2-Tb/s throughput and show packet switching with four ports running at 40 Gb/s each.