Optical space switch

Claim 2

An optical space switch comprising: an optical output; n optical deflection stages each comprising a polarization rotator responsive to a respective control signal to rotate the polarization of an optical signal through 90°, and a deflection means for selectively deflecting optical signals according to their polarization; said n deflection stages being serially arranged to define 2 n distinct source locations from where any single optical signal is selectively deflectable successively by the n deflection stages to said optical output, a distinct combination of states of the n control signals corresponding to each location; a plurality of up to 2 n optical sources each located at one of said 2 n source locations; and in which each deflection stage preserves the spatial integrity of the deflected optical signals.

Claim 3

A switch as claimed in claim 1 in which the optical sources emit an optical signal whose spatial modulation is representative of at least one binary word.

Claim 4

An optical space switch comprising: an optical output; n optical deflection stages each comprising a polarization rotator responsive to a respective control signal to rotate the polarization of an optical signal through 90°, and a deflection means for selectively deflecting optical signals according to their polarization; said n deflection stages being serially arranged to define 2 n distinct source locations from where any single optical signal is selectively deflectable successively by the n deflection stages to said optical output, a distinct combination of states of the n control signals corresponding to each location; a plurality of up to 2 n optical sources each located at one of said 2 n source locations, said optical sources each comprising a plurality of optical fibers; and in which each deflection stage preserves the spatial integrity of the deflected optical signals.

Claim 5

An optical space switch comprising: an optical output; n optical deflection stages each comprising a polarization rotator responsive to a respective control signal to rotate the polarization of an optical signal through 90°, and a deflection means for selectively deflecting optical signals according to their polarization; said n deflection stages being serially arranged to define 2 n distinct source locations from where any single optical signal is selectively deflectable successively by the n deflection stages to said optical output, a distinct combination of states of the n control signals corresponding to each location; a plurality of up to 2 n optical sources each located at one of said 2 n source locations, said optical sources each comprising a plurality of optical fibers; and in which each deflection stage preserves the spatial integrity of the deflected optical signals.

Claim 6

An optical space switch comprising: an optical output; n optical deflection stages each comprising a polarization rotator responsive to a respective control signal to rotate the polarization of an optical signal through 90°, and a deflection means for selectively deflecting optical signals according to their polarization; said n deflection stages being serially arranged to define 2 n distinct source locations from where any single optical signal is selectively deflectable successively by the n deflection stages to said optical output, a distinct combination of states of the n control signals corresponding to each location; a plurality of up to 2 n optical sources each located at one of said 2 n emitter locations, said optical sources each comprising a plurality of individually modulated optical emitters; and in which each deflection stage preserves the spatial integrity of the deflected optical signals.

Claim 7

An optical space switch comprising: an optical output; n optical deflection stages each comprising a polarization rotator responsive to a respective control signal to rotate the polarization of an optical signal through 90°, and a deflection means for selectively deflecting optical signals according to their polarization; said n deflection stages being serially arranged to define 2 n distinct source locations from where any single optical signal is selectively deflectable successively by the n deflection stages to said optical output, a distinct combination of states of the n control signals corresponding to each location; a plurality of up to 2 n optical sources each located at one of said 2 n emitter locations, said optical sources each comprising a plurality of individually modulated optical emitters; and in which each deflection stage preserves the spatial integrity of the deflected optical signals.

Claim 8

A switch as claimed in either claims 1, 3 or 4 in which said deflection means comprises a birefringent material.

Claim 9

A switch as claimed in claim 5 in which said birefringent material is calcite.

Claim 10

A switch as claimed in either claims 1, 3 or 4 in which said deflection means comprises a combination of polarization beamsplitters and prisms.

Claim 11

A switch as claimed in either claims 1, 3 or 4 in which said polarization rotator is a twisted-nematic liquid crystal.

Claim 12

A switch as claimed in either claims 1, 3 or 4 in which the optical signals are collimated.

Claim 13

A switch as claimed in either claims 1, 3 or 4 in which said optical sources provide divergent optical signals and further comprising a means for directing the optical signal which emerges axially from the final deflection stage to said output.

Claim 14

A switch as claimed in either claims 1, 3 or 4 in which each said optical source is capable of launching an optical signal which is spatially modulated transverse to the signal propagation direction.

Claim 15

An optical space switch comprising: n optical deflection stages serially arranged, each comprising a polarization rotor and a deflector for selectively deflecting optical signals according to their polarization; said polarization rotor alters the polarization of an optical signal in response to a control signal; said n deflection stages define 2 n distinct source locations, an optical signal from any of said locations is selectively deflectable to an optical output by said deflection stages, a unique combination of states of said control signals corresponding to each location, and up to 2 n optical sources each located at one of said source locations.

Claim 16

An optical space switch comprising: n optical deflection stages serially arranged, each comprising a polarization rotor and a deflector for selectively deflecting optical signals according to their polarization; said polarization rotor alters the polarization of an optical signal in response to a control signal; said n deflection stages define 2 n distinct source locations, an optical signal from any of said locations is selectively deflectable to an optical output by said deflection stages, a unique combination of states of said control signals corresponding to each location, and up to 2 n optical sources each located at one of said source locations.

Claim 17

An optical connection network comprising: n passive optical signal distributors, each distributor receiving an optical input signal and emitting m duplicate signals copied from said optical input signal; m optical space switches wherein each switch receives at said source locations one of said m duplicate signals from each distributor, and said optical signals being the emitted signals from the distributor, each optical space switch comprising: an optical output; n optical deflection stages each comprising a polarization rotator responsive to a respective control signal to rotate the polarization of an optical signal through 90°, and a deflection means for selectively deflecting optical signals according to their polarization; said n deflection stages being serially arranged to define 2 n distinct source locations from where any single optical signal is selectively deflectable successively by the n deflection stages to said optical output, a distinct combination of states of the n control signals corresponding to each location; a plurality of up to 2 n optical sources each located at one of said 2 n source locations; and in which each deflection stage preserves the spatial integrity of the deflected optical signals.

Claim 18

An optical connection network comprising: n passive optical signal distributors, each distributor receiving an optical input signal and emitting m duplicate signals copied from said optical input signal; m optical space switches wherein each switch receives at said source locations one of said m duplicate signals from each distributor, and said optical signals being the emitted signals from the distributor, each optical space switch comprising: an optical output; n optical deflection stages each comprising a polarization rotator responsive to a respective control signal to rotate the polarization of an optical signal through 90°, and a deflection means for selectively deflecting optical signals according to their polarization; said n deflection stages being serially arranged to define 2 n distinct source locations from where any single optical signal is selectively deflectable successively by the n deflection stages to said optical output, a distinct combination of states of the n control signals corresponding to each location; a plurality of up to 2 n optical sources each located at one of said 2 n source locations; and in which each deflection stage preserves the spatial integrity of the deflected optical signals.