For decades, researchers developing electronics have had enormous success advancing almost any application that has to do with information processing: following Moore's Law, data density on an electronic chip has doubled every 18 months. Although this exponential growth is likely to continue for a while, inherent physical limitations are expected to prevent it from lasting indefinitely. Some of these limitations are already evident: as electronics in computers are forced to operate at ever higher frequencies, power dissipation and consequent hardware heating are becoming a very serious problem. In nodes of optical telecommunications networks, where data needs to be processed electronically at especially high operational frequencies, the problem is even more significant.

Realizing that electronic signal processing would eventually face a fundamental physical limitation, engineers in the early 1980s explored the possibility of building an optical computer, in which data would be carried by light (photons) instead of by charged carriers (electrons). They didn't have an easy time. True all-optical signal processing requires a way of influencing light with light itself. That is, one has to use materials with optical properties that can be modified by the presence of a light signal; this can be used to influence another light signal, thereby performing an all-optical signal-processing operation. Unfortunately, these effects tend to be extraordinarily weak, so the proposed optical logic elements of the 1980s were too large; they consumed orders of magnitude too much power to be feasible. People started viewing optical signal processing as impractical.