Title :
Optical RAM and Flip-Flops Using Bit-Input Wavelength Diversity and SOA-XGM Switches
Author :
Vagionas, Christos ; Fitsios, Dimitrios ; Kanellos, George T. ; Pleros, Nikos ; Miliou, Amalia
Author_Institution :
Dept. of Inf., Aristotle Univ. of Thessaloniki, Thessaloniki, Greece
Abstract :
In this paper, we demonstrate a novel RAM cell based only on three traveling waveguide semiconductor optical amplifier-cross gain modulation (SOA-XGM) switches. The RAM cell features wavelength diversity in the incoming bit signals and provides Read/Write operation capability with true random access exclusively in the optical domain. Two of the SOA-XGM switches are coupled together through an 70/30 coupler to form an asynchronous flip-flop, which serves as the memory unit. Random access to the memory unit is granted by a third SOA-ON/OFF switch and all three SOAs together form the proposed RAM cell. Proof-of-principle operation is experimentally demonstrated at 8 Mb/s using commercial fiber-pigtailed components. The distinctive simplicity of the proposed RAM cell architecture suggests reduced footprint. The proposed flip-flop layout holds all the credentials for reaching multi-Gb/s operational speeds, if photonic integration technologies are employed to obtain wavelength-scale waveguides and ultrashort coupling lengths. This is numerically confirmed for 10 Gb/s using a simulation model based on the transfer matrix method and a wideband steady-state material gain coefficient.
Keywords :
flip-flops; high-speed optical techniques; optical modulation; optical waveguides; photonic switching systems; random-access storage; semiconductor optical amplifiers; SOA-XGM switches; asynchronous flip-flop; bit-input wavelength diversity; commercial fiber-pigtailed components; flip-flop layout; optical RAM; photonic integration technologies; random access; read/write operation; semiconductor optical amplifier-cross gain modulation; transfer matrix; traveling waveguide; ultrashort coupling lengths; wavelength-scale waveguides; Optical attenuators; Optical fibers; Optical signal processing; Optical switches; Random access memory; Semiconductor optical amplifiers; Optical flip-flop; optical memory; optical signal processing; semiconductor optical amplifier (SOA); transfer matrix method (TMM);
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2012.2210696