WDM-Enabled Optical RAM at 5 Gb/s Using a Monolithic InP Flip-Flop Chip

We experimentally demonstrate an all-optical static random access memory (RAM) cell using a novel monolithic InP set-reset flip-flop (FF) chip and a single hybridly integrated semiconductor optical amplifier-Mach-Zehnder interferometer (SOA-MZI)-based access gate employing wavelength division multiplexing (WDM) data encoding. The FF device is a 6×2 mm
²
InP chip having a 97.8% reduced footprint compared with previous FF devices that were successfully employed in optical RAM setups. Successful and error-free RAM operation is demonstrated at 5 Gb/s for both read and write functionalities, having a power penalty of 4.6 dB for write and 0.5 dB for read operations. The theoretical potential of this memory architecture to allow RAM operation with memory speeds well beyond 40 GHz, in combination with continuously footprint-reducing techniques, could presumably lead to future high-speed all-optical RAM implementations that could potentially alleviate electronic memory bottlenecks and boost computer performance.