Abstract
Silicon-photonics is an emerging techno logy that can overcome the tradeoffs faced by traditional electrical I/O. Due to ballooning development costs for advanced CMOS nodes, however, widespread adoption necessitates seam less photonics in- tegration into mainstream proce sses, with as few process changes as possible. In this work, we demonstrate a silicon-photonic link with optical devices and electronics integrat ed on the same chip i na0 . 1 8µ mb u l kC M O Sm e m o r yp e r i p h e r yp r o c e s s .T oe n a b l e waveguides and optics in process-n ative polysilicon, we introduce deep-trench isolation, placed underne ath to prevent optical mode leakage into the bulk silicon substrate, and implant-amorphization to reduce polysilicon loss. A res onant defect-trap photodetector using polysilicon eliminates need fo r germanium integration and completes the fully polysilicon-based photonics platform. Trans- ceiver circuits take advantage of photonic device integration, achieving 350 fJ/b transmit and 71 µA pp BER = 10 -12 receiver sensitivity at 5 Gb/s. We show hig h fabrication uniformity and high-Q resonators, enabling den se wavelength-division multi- plexing with 9-wavelength 45 Gb/s transmit/receive data-rates per waveguide/fiber. To combat perturbations to variation- and thermally-sensitive resonant dev ices, we demonstrate an on-chip thermal tuning feedback lo op that locks the resonance to the laser wavelength. A 5 m optical chip-to -chip link achieves 5 Gb/s while con