An architecture for frame integrity optical TDM switching

Abstract

An architecture for optical time-division-multiplexing (TDM) switching which makes more efficient use of hardware is presented. The number of switches used is very close to the theoretical minimum. Lithium niobate switches, with fiber delay lines for storage, are used throughout, and the architecture allows the bit rate and wavelength transparency of these devices to be exploited. The networks are mathematically equivalent to Benes and Waksman networks, and they are constructed using recursive definitions which are justified mathematically. The use of 'feedforward' rather than 'feedback' delays produces superior crosstalk performance and more uniform attenuation than existing designs. The networks may be dilated in a similar way to dilated Benes networks, yielding vastly improved crosstalk performance at the expense of using roughly twice as many switches. >