Low-power multichip module and board-level links for data transfer

Advanced device technologies such as vertical cavity surface emitting lasers (VCSELs) and diffractive micro lenses can be combined with novel packaging techniques to allow low-power interconnection of parallel optical signals. These interconnections can be realized directly on circuit boards, in a multi-chip module format, or in packages that emulate electrical connectors. For applications such as stacking of multi-chip module (MCM) layers, the links may be realized in bi-directional form using integrated diffractive microlenses. In the stacked MCM design, consumed electrical power is minimized by use of a relatively high laser output from high efficiency VCSELs, and a receiver design that is optimized for low power, at the expense of dynamic range. WIthin certain constraints, the design may be extended to other forms such as board-level interconnects.