Optical Multilevel Signaling for High Bandwidth and Power-Efficient On-Chip Interconnects

The scalability of high-performance computing systems is increasingly dependent on high-bandwidth and power-efficient communication between a growing number of processing cores on-and off-chip. Recent developments in silicon photonics technology can potentially alleviate many of the challenges associated with these stringent interconnection demands. In this letter, we propose the use of an optical multilevel signaling technique for on-chip interconnects in conjunction with wavelength division multiplexing to double the aggregate communication bandwidth without increasing the number of waveguides and wavelengths used, thereby reducing scaling costs.