Signal processing beyond conventional limits

It is argued that any useful photonic processor is unlikely to incorporate direct photon storage; rather, it is expected to perform pipelined operations that cannot be drastically delayed. In spite of this, optical processing holds critical importance that will only grow as operational speeds in lightwave communications increase. Indeed, 400 Gbps commercial channel requires electronic backplane that poses significant challenge with respect to dissipation, sampling speed and post-reception processing. By interfacing purely electronic backplane to photonic preprocessing layer, these challenges can be addressed in qualitatively different manner. In contrast to traditional vision of optical processing in which electronic functions are entirely displaced, the real prospect for advanced processor leads to the hybrid constrict: specialized, fast functions will be performed in preprocessing optical stage designed to condition and pass signals at much slower rate to the matched electronic plane. Such construct will not only provide for qualitatively higher (aggregate) throughput, but will also lead to drastic decrease in dissipation and size. Consequently, the strict boundary, presently seen in O/E interface, will be blurred in the future, bringing us closer to the original (if misguided) concept of optical processor.