Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : logic gates


Inmar N. Ghazi

Engineering and Technology Journal, 2008, Volume 26, Issue 9, Pages 1143-1157

In this paper few high speed (i.e. as high as 80 GB/s) all-optical logic gates has been studied.
These logic gates include a ( 80Gb/s XOR ) gate using semiconductor optical amplifier (SOA)
based Mach-Zehnder interferometer incorporated with a delayed interferometer (DI), The
performance of XOR operation has been investigated using numerical simulations. The quality of
the XOR result is improved using a (DI) delayed interferometer after the Mach-Zehnder
interferometer. . A (80Gb/s XNOR) gate using four wave mixing (FWM) in highly nonlinear
fibers (HNLF) have been studied also, the four wave mixing process is a very fast process in
fibers ,the nonlinear Schrödinger equation that describes (FWM) process in fiber is solved
numerically using the split-step Fourier transform method ,this scheme is capable of operating at
a data rate as high as 250Gb/s ,finally A(40Gb/s) NOR gate operation has been analyzed by a
numerical solution of the SOA rate equations. To investigate the quality of NOR operation by
simulation, Q factor of the NOR output signal has been calculated. Q factor gives the information
of the optical signal to noise ratio in digital transmission .All numerical simulation programs
performed through Matt-Lab 7.0 prgram.