On-Chip Wireless Optical Broadcast Interconnection Network

An on-chip wireless optical broadcast network for future multicore CPU interconnections is introduced in this paper. A baseline topology is composed of 32 identical transmitting/receiving optical dielectric rod antennas arranged around a circular ring. To ensure balanced power distribution between the channels, the optical antenna design was governed by the antennas' far-field radiation pattern and near-field coupling. Over the frequency range of 172 THz (1750 nm) and 222 THz (1350 nm), the broadcasting network has average and minimum transmissions of ${-}16$ and ${-}21.5$ dB, respectively. The overall transmission efficiency is maintained above 70% throughout the operating bandwidth. Results are confirmed by the full-wave simulations based on finite integration and finite element methods. For additional validation, an eight-channel microwave broadcasting network is fabricated, and excellent agreement between the full-wave design and measurements are obtained.