Introduction Research Results Further research Publications and patents : one patent pending. : 2 published, 2 writing : 3 presentation (2 in international conferences) A different, interesting issue worth to consider is the use of modules containing several different, independent addressable permutations (sharing the same folding properties). This can lead to a concurrent multistage interconnection paradigm not based on size-reduced (elemental) crossbars (as in most multistage networks) but on cascaded permutation-reduced crossbars instead. Promising buffer-based architectures based on this paradigm as well as routing algorithms are currently being explored in our lab. A lot of effort has been put on free-space interconnects as a way to alleviate the wiring congestion inherent to planar VLSI technology. However, industry is still awaiting for a reliable support, comparable in robustness to optical fibers (1D) or planar guided-wave optics (2D). We present here first steps towards a set of robust, pre-aligned 3D fiber-based interconnection blocks, usable as elemental building modules for most parallel computing architectures. Thanks to the guided nature of the interconnect, we can expect these to achieve better efficiency than diffractive optics, while the use of a third dimension will certainly eliminate cross-talk. Misalignment measurement Active Alignment OFF Active Alignment ON Frequency [Hz] Misalignment Reduction Ratio (Active Alignment ON / OFF) Quadrant photodetector VCSEL xy Piezo Stage Vibration generator Controller Interconnection optics Control signal VCSEL Vibration generator Interconnection optics Quadrant detector Piezo microstage Although technologically challenging, there is no fundamental reason excluding the use of optical fibers as a way to implement complex interconnection patterns between plane arrays. However, compared to free-space optics, alignment (of both inputs and outputs) may represent a real challenge. Our solution consist of using pre-aligned micromachined fiber-holder arrays. Also, multistage architectures using regular plane-to-plane wave-guide based interconnections may represent (today) the most advantageous hardware implementation of a theoretically-optimal architecture for massively interconnected systems, so we have concentrated on the design of inter-stage single or multiple- permutation modules. Active alignment is being explored as a way to deal with the interconnection difficulties inherent to the cascading of the modules, or even for selecting (switching) them. We plan to use several similar modules to build a spanned hypercube network with TDM (Time-Division- Multiplexed) weak communication links. As a demonstration of these principles, we implementing whole shuffle- exchange multi-stage interconnection networks (using these modules and the optoelectronic processor arrays developed in our lab for the Vision-Chip project). We have designed, fabricate and tested a folded 16-input/output exchange permutation module, where cross-talk between channels is made negligible. Scalability and modularity of the blocks is another important issue being explored through fractal and row/column recursive decomposition. Time Division Multiplexed Banyan network with global switching PPT Created: Alvaro 28/10/2002