3x3 all-fibre routing switch

An all-fibre acousto-optic switch has been constructed from a 3x3 null fused coupler. The maximum drive power required is 4 mW, the switching time is 100µs and the insertion loss is less than 0.5 dB. The switch shares the advantages of an earlier 2x2 switch but with more fibre ports. and should permit the design of compound routing arrays with fewer switching elements per channel