Optical PCB interconnects, Niche or mainstream?

Summary form only given. The continued scaling of information processing systems-on-a-chip using modern technology have made conventional electrical interconnects using copper the bottleneck for data traffic in many applications. Efforts in the area of optical backplane and technology have been underway for several years, generating significant interest due to its potential benefits in power, density and speed. Recently, these efforts have led to discussions regarding the role of embedded optics for chip to chip communication on printed circuit boards. Most signficantly, the advancement in silicon photonics compatible to CMOS technology have accelerated this discussion. A consensus appears to be emerging that PCB interconnects for mainframes and high-end servers will leverage optical technologies, but will these approaches ever go mainstream?