Picosecond optical apparatus utilizing optically induced birefringence in solids

Claim 2

An optical device comprising a body of a solid material in which birefringence can be optically induced, said body being disposed to intercept an optical information signal, means for generating an optical control pulse of substantially high power density and of picosecond duration or less, means for applying to said body the optical control pulse coincident with the transmission of at least a portion of the information signal through said body to induce the birefringence in a sense yielding a change in polarization of the portion of the information signal.

Claim 3

The optical device of claim 1 wherein said solid material is selected from the group consisting of germanium, silicon, gallium arsenide, diamond, strontium titanate, cuprous chloride and glass.

Claim 4

The device of claim 1 for use in modulating the optical information signal comprising means for polarizing the information signal in a first direction, means for polarizing the control pulse at an angle of about 45* to said first direction, means for making the polarized control pulse and the polarized information signal to be coincident and to overlaP in at least a portion of said body, thereby to cause the polarization of the information signal to change from said first direction to a second direction at approximately 90* to said first direction.

Claim 5

The device of claim 3 in combination with means for selectively transmitting the optical information signal polarized in said first direction and for absorbing the information signal polarized in said second direction.

Claim 6

The device of claim 4 wherein the optical information signal comprises a train of optical pulses of uniform spacing T and wherein the control pulse comprises an optical pulse of duration less than T.

Claim 7

The device of claim 5 wherein T is a subpicosecond time interval.

Claim 8

The device of claim 4 for use as a multiplexer wherein the optical information signal comprises a train of uniformly spaced pulses, a subset thereof defining a frame and each pulse in said frame corresponding to a different channel, and in combination with a plurality of said bodies disposed along a common optic axis, each of said bodies corresponding to a separate one of said channels, the information signal being transmitted along said common axis, and means for selectively applying a control pulse to each of said bodies coincident with the passage therethrough of the information pulse of a corresponding channel.

Claim 9

The device of claim 4 for use as a demultiplexer wherein the optical information signal comprises a train of encoded pulses, a subset thereof defining a frame and each pulse position in said frame corresponding to a different channel, and in combination with means for dividing the information signal into a plurality of paths, each of said paths corresponding to a separate channel, a plurality of said bodies, each of said paths having disposed therein one of said bodies, means for selectively applying a control pulse to each of said bodies coincident with the passage therethrough of the information pulse of a corresponding channel, and means for transmitting in each of said paths only the information pulses which have been priorly made coincident with a corresponding control pulse.