  Traditional silicon-on-insulator (SOI) platform based on-chip photonic
interconnects have limited energy-bandwidth scalability due to the optical
non-linearity induced power constraints of the constituent photonic devices. In
this paper, we propose to break this scalability barrier using a new
silicon-on-sapphire (SOS) based photonic device platform. Our physical-layer
characterization results show that SOS-based photonic devices have negligible
optical non-linearity effects in the mid-infrared region near 4{\mu}m, which
drastically alleviates their power constraints. Our link-level analysis shows
that SOS-based photonic devices can be used to realize photonic links with
aggregated data rate of more than 1 Tb/s, which recently has been deemed
unattainable for the SOI-based photonic on-chip links. We also show that such
high-throughput SOS-based photonic links can significantly improve the
energy-efficiency of on-chip photonic communication architectures. Our
system-level analysis results position SOS-based photonic interconnects to pave
the way for realizing ultra-low-energy (< 1 pJ/bit) on-chip data transfers.
