Bit-serial architecture for optical computing

Abstract

The design of a complete, stored-program digital optical computer is described. A fully functional, proof-of-principle prototype can be achieved by using LiNbO(3) directional couplers as logic elements and fiber-optic delay lines as memory elements. The key design issues are computation in a realm where propagation delays are much greater than logic delays and implementation of circuits without fip-flops. The techniques developed to address these issues yield architectures that do not change as their clocking speed is scaled upward and the size is scaled downward proportionally; these are called speed-scalable architectures. Signal amplitude restoration and resynchronization are accomplished by the novel technique of switching in a fresh copy of the system clock. Device characteristics that are important to the proof-of-principle demonstration are discussed, including the special properties and limitations that are important when designing with them. Design principles are exemplified by the design of an n-bit counter. Following this, the design for a stored-program bit-serial computer is described. We estimate that the described prototype architecture can be operated in the 100-MHz region with off-the-shelf components, and in the O. 1-1-THz region with foreseeable future components.

Coupling Single Photons from Discrete Quantum Emitters in WSe2 to Lithographically Defined Plasmonic Slot Waveguides

“…[1][2][3][4] It was already recognized several decades ago that shifting from electronic to photonic devices 5,6 promises ultra high-rate data processing, with maximum accessible clock speeds beyond ∼THz. 7 In terms of the energy required to process a single bit of information, all-optical approaches lead the way.…”

Integer Sorting and Routing in Arrays With Reconfigurable Optical Buses

“…The use of online switching is of particular importance for the AROB because signal amplitude restoration and re-synchronization can be accomplished by the technique of switching in a fresh copy of the system clock, see Ref. [16]. However, although expensive, all the opto-electronic devices assumed by our model exist.…”

“…Descriptions of an optical counter can be found in Ref. [16] and of an optical shift register in Ref. [15].…”

All-Optical Network Coding

“…3) All-Optical Logic Gates: Architectures for optical computing have been proposed which take advantage of the fact that 2×2 switches are sufficient for realizing all possible logic gates (assuming the existence of constants 0 and 1 as well as fan-out which can be implemented with a passive splitter) [41]. [44].…”