Terahertz optical asymmetric demultiplexer

Abstract

An optical demultiplexer includes an optical loop having first and second terminals and a mid point. A non-linear optical element is positioned in the loop at a distance .DELTA.x from the mid point. A first coupler is positioned in the loop and has a gating pulse applied which causes a change in the optical property of the non-linear optical element from a first state to a second state. A second coupler is optically coupled to the first and second terminals and has an input terminal for receiving a series of input optical pulses. The second coupler responds by inducing, for each input pulse, a pair of counter-propagating pulses in the optical loop. Control circuitry causes a gating pulse to be applied to the optical loop and to be timed to switch the non-linear optical element to from a first to a second state after one of the pair of counter-propagating pulses has passed through the non-linear optical element, but before the other counter-propagating pulse has reached the non-linear optical element. In this manner, one counterpropagating pulse is affected by the second state of the non-linear optical element and the other counterpropagating pulse is not, thereby enabling a differential signal to exit from the output of the second coupler to a detector.

Dependencies are inferred from the claim text.