Description and evaluation of the FAST-Net smart pixel-based optical interconnection prototype

Abstract

The design, packaging approach, and experimental evaluation of the free-space accelerator for switching terabit networks (FAST-Net) smart-pixel-based optical interconnection prototype are described. FAST-Net is a high-throughput data-switching concept that uses a reflective optical system to globally interconnect a multichip array of smart pixel devices. The three-dimensional optical system links each chip directly to every other with a dedicated bidirectional parallel data path. in the experiments, several prototype smart-pixel devices were packaged on a common multichip module (MCM) with interchip registration accuracies of 5-10 /spl mu/m. The smart-pixel arrays (SPAs) consist of clusters of oxide-confined vertical-cavity surface-emitting lasers and photodetectors that are solder bump-bonded to Si integrated circuits. The optoelectronic elements are arranged within each cluster on a checkerboard pattern with 125-/spl mu/m pitch. The experimental global optical interconnection module consists of a mirror and lens array that are precisely aligned to achieve the required interchip parallel connections between up to 16 SPAs. Five prototype SPAs were placed on the MCM to allow the evaluation of a variety of interchip links. Measurements verified the global link pattern across several devices on the MCM with high optical resolution and registration. No crosstalk between adjacent channels was observed after alignment. The I/O density and efficiency results suggest that a multi-terabit switch module that incorporates global optical interconnection to overcome conventional interconnection bottlenecks is feasible.