Optical computing and the Fredkin gates

Logic synthesis for integrated optics

“…Previous work using MZIs: Optical logic design using crossbar routing devices has been investigated in literature. Shamir, Caulfield, et al and others investigated the use of optical crossbar gates as Fredkin gates [11] [12]. The Fredkin gate model assumes that an optical input can also drive the switching input of a gate, allowing the gate to be used in a reversible logic role, but precluding its applicability to our device model.…”

The logic of optics and the optics of logic

“…We ourselves noted that lossy conservative logic gates were still interesting [11] and that certain parallel operations could be done quantum mechanically using coherent optics [12][13][14][15][16].…”

Optical Symbolic Processor for Expert System Execution

“…A photorefractive gate based on four-wave mixing is an all-optical approach mentioned by the authors in [56]. Besides the two incident input message beams, the control consists of two pump beams.…”

“…Note that this approach differs significantly from the polarization switching gate discussed by Shamir et al [56]. In that gate, signals passing through a electrooptic modulator are rotated I by 90' when the gate is activated electrically.…”