The need to obtain faster processor has resulted in larger number of gates on the chip die. We tend to see larger processors as more efficient methods of integrating larger number of transistors. But due to interconnect bottleneck there would be a certain upper limit to which we could go.
Metallic interconnects on chip are typically associated with high time constants and add to the overheads when it comes to optimizing for high clock speeds. With increasing component density on chip there would even be a need to have faster interconnect between the devices to still enable single clock operation on the chip.
Optical Interconnects have the natural advantage of high bandwidth, high interconnection density and superior performance overall as an interconnection system. Most of all realized interconnection architecture using optical components facilitates parallel processing.
A typical component of an interconnect could be a switch that operates at Giga Hertz ranges and comprises of a Surface emitting Laser (VCSEL) that is powered by a driver designed using CMOS/BiCMOS technology. The Laser lases through a micro lens and reaches a particular detector which is envisaged as a part of the receiver that is designed with similar technology as the driver. The receiver comprises of Flip Chip Bondable photo detectors and transimpedance amplifiers. Use of Flip Chip interconnection lowers propagation delay and also increases interconnection density.
Proper simulation and design of the optical micrograting can facilitate various connection strategies for the hybrid optoelectronic configuration. One of the primary solution to design would be to implement a GPIB (General purpose Interface Bus). The grating can be designed to create a one to 'n' fanout and these fanouts can be sensed using detectors.
High density parallel processing could be facilitated since the laser beams can crossover without interfering. Potential application for optical switches could be in network systems that require giga-hertz switching speeds and re-configurability. Potential application may lie in integrating these Opto-MCMs in fiber optic repeater units for short/long haul communications.
