All-Optical Passive Transistor Using Counter-Propagating Beams in a Nonlinear Mach-Zehnder Interferometer

A novel all-optical passive transistor using counter propagating beams in a nonlinear Mach-Zehnder interferometer is proposed. The proposed all-optical passive transistor always gives "pure" output (i.e., output contains only one of the two input beams and not a mixture of the input beams). To the best of our knowledge, this is the first proposal of an all-optical device which (i) functions with mutually incoherent (of same wavelength and polarization) as well as mutually coherent inputs and (h) gives a phase insensitive performance while functioning with coherent inputs. The proposed all-optical passive transistor can amplify a signal with zero amplifier noise and mimic NOT, AND, (and hence), NAND gates.