3 x 3 all-fiber routing switch

An all-fiber acoustooptic switch has been constructed from a 3×3 null fused coupler. The maximum drive power required is 4 mW, the switching time is 100 μs and the insertion loss is less than 0.5 dB and has a cross talk of 20 dB. The switch shares the advantages of an earlier 2×2 switch but with more fiber ports, and should permit the design of compound routing arrays with fewer switching elements per channel.