mNoC: Large Nanophotonic Network-on-Chip Crossbars with Molecular Scale Devices

Moore's law and the continuity of device scaling have led to an increasing number of cores/nodes on a chip, creating a need for new mechanisms to achieve high-performance and power-efficient Network-on-Chip (NoC). Nanophotonics based NoCs provide for higher bandwidth and more power efficient designs than electronic networks. Present approaches often use an external laser source, ring resonators, and waveguides. However, they still suffer from important limitations: large static power consumption, and limited network scalability.

In this article, we explore the use of emerging molecular scale devices to construct nanophotonic networks: Molecular-scale Network-on-Chip (mNoC). We leverage on-chip emitters such as quantum dot LEDs, which provide electrical to optical signal modulation, and chromophores, which provide optical signal filtering for receivers. These devices replace the ring resonators and the external laser source used in contemporary nanophotonic NoCs. They reduce energy consumption or enable scaling to larger crossbars for a reduced energy budget. We present a Single Writer Multiple Reader (SWMR) bus based crossbar mNoC. Our evaluation shows that an mNoC can achieve more than 88% reduction in energy for a 64×64 crossbar compared to similar ring resonator based designs. Additionally, an mNoC can scale to a 256×256 crossbar with an average 10% performance improvement and 54% energy reduction.