Optical switch reaches record throughput

An optical crossconnect switch that can route any of 112 input channels to any of 112 outputs has been developed by Lucent Technologies. Based on micro-electromechanical systems (MEMS) mirrors, it is "the largest fully functional, fully configured optical crossconnect" yet demonstrated, said David Neilson of Bell Labs (Holmdel, NJ) in a postdeadline paper presented at the 2000 Optical Fiber Communication conference (Baltimore, MD) last March. A microlens array focuses light from input fibers onto a two-dimensional array of MEMS mirrors that can tilt ±5° on each of two axes. Each micromirror bounces the input beam to a fixed reflector that directs it back to another micromirror in the array. That mirror, in turn, reflects the light to the output fiber. Neilson said switching times were less than 10 ms, and insertion loss was 7.5 ±2.5 dB. A major advantage is that the number of active switching elements increases with the port count N, not the number of possible connections N². "It should be scalable to port counts greater than 1000," said Neilson. By testing the switching array with a 320-Gbit/s data stream at one wavelength, they achieved a switching rate of 35.8 Tbit/s. Contact David Neilson at [email protected].