Weexperimentallydemonstratea16×16reconfigurablynonblockingopticalswitchfabricusingaBenesarchitecture.Theswitchfabricconsistsof562×2Mach–Zehnderinterferometerbasedelementaryswitches,witheachintegratedwithapairofwaveguidemicroheaters.Theaverageon-chipinsertionlossis~5.2dBforbothofthe'all-cross'andthe'all-bar'states,withalossvariationof1dBoverallroutingpaths.Thecrosstalkforallswitchingstatesisbetterthan-30dB.Theswitchingtimeoftheswitchelementisabout22μs.Theswitchingfunctionalityisverifiedbytransmissionofa40Gb∕squadraturephase-shiftkeyingopticalsignal.