Optical interconnects at the multi-chip module level; a view from the system level

To the optical interconnect technologist, there exists a vision of implementation of the optical alternative at the multi-chip module (MCM) level. Expressed in its most basic form, the vision is that of a MCM being designed at a computer terminal wherein the designer has 10 or more layers of metal interconnect levels available,and perhaps 2 other layers, referred to as “opto” layers (optol, opto2). The opto layers consist of some electronically compatible dielectric layer that can be laid down and patterned to form very low-loss optical waveguides within the multi-layer MCM structure. These waveguides, and the associated driver/receiver electronics, have sufficiently superior optical performance characteristics and sufficiently robust mechanical/thermal properties that implementing them at the MCM level amounts to straightforward delineation of design rules for the layout engineer