Comparison of Optical and Electrical Interconnects for Intrachip Communications

We simulated and compared optical and electrical interconnects for intrachip communications, focusing particularly on the dependence of the power consump tion versus the interconnect length and the transmis sion throughput. We conclude that optoelectronic interconnects today consume less energy when the interconnect length is (typically) longer than (23) mm. The competition is clearly open in the future. Optical interconnects might contribute to solve onchip power consump tion and crosstalk issues, provided that their technology becomes cheap, compatible with the CMOS processes, and that it will be possible to reduce the threshold current of the VCSEL emitters down to a few μAmps.