Ultra-thin silicon-on-sapphire component technology for short reach parallel optical interconnects

Parallel optical interconnects are gaining popularity in data communications applications requiring short distance (<300 m) and high bandwidth (>10 Gbps) links. This article describes the merging of three crucial technologies applicable to parallel optical interconnects: CMOS circuitry, 850 nm VCSEL technology, and chip-scale-packaging. We describe CMOS ICs demonstrated in an opto-electronic module based on ultra thin silicon, UTSi^® CMOS. These CMOS on sapphire ICs enable high speed, low power driver and TIA functions on a transparent substrate that is an integral element of a unique assembly technique called flipped optical chips on UTSi, FOCUTS^®, technology. Performance of the IC functions is discussed, showing compliance with 3.125 Gbps standards. Assembled modules that transmit 850 nm VCSEL light through the transparent sapphire substrate and into self-aligned optical elements for transmission through either parallel fibers or free space are also described and measured performance presented.