AN OPTICAL SPACE SWITCH

An optical space switch comprising an optical output (O); three optical deflection stages (S) each comprising a twisted-nematic liquid crystal polarisation rotator (R) responsive to a respective bi-state control signal and a calcite crystal deflection means (D) for selectively deflecting optical signals according to their polarisation; the deflection stages (D) being serially arranged to define eight distinct source locations from where an optical signal is selectively deflectable successively by the deflection stages (D) to the optical output (O), a distinct combination of states of the three control signals corresponding to each location eight optical sources (I) are located at one of the source locations. Each input is formed from an array of fibres so as to be capable of launching an optical signal which is spatially modulated transverse to the signal propagation direction. Each deflection stage (S) preserves the spatial integrity of the deflected optical signals.