Free-space parallel multichip interconnection system

A parallel data-communication scheme is described for interchip communication with free-space optics. We present a proof-of-concept and feasibility demonstration of a practical modular packaging approach in which free-space optical interconnect modules can be simply integrated on top of an electronic multichip module (MCM). Our packaging architecture is based on a modified folded 4-f imaging system that is implemented with off-the-shelf optics, conventional electronic packaging techniques, and passive assembly techniques to yield a potentially low-cost packaging solution. The prototype system, as built, supports 48 independent free-space channels with eight separate laser and detector chips, in which each chip consists of a one-dimensional array of 12 devices. All chips are assembled on a single ceramic carrier together with three silicon complementary metal-oxide semiconductor chips. Parallel optoelectronic (OE) free-space interconnections are demonstrated at a speed of 200 MHz. The system is compact at only 10 in.3 (μ164 cm³) and is scalable because it can easily accommodate additional chips as well as two-dimensional OE device arrays for increased interconnection density.