A 25Gb/s 4.4V-Swing AC-Coupled Si-Photonic Microring Transmitter with 2-Tap Asymmetric FFE and Dynamic Thermal Tuning in 65nm CMOS Conference Paper uri icon


  • 2015 IEEE. Silicon photonic microring modulators (MRMs) offer a promising approach for realizing energy-efficient wavelength-division multiplexing (WDM) optical interconnects. For data-rates greater than 10Gb/s, depletion-mode MRMs are generally preferred over their injection-mode counterparts due to their shorter carrier lifetimes and resulting higher bandwidths. Unfortunately, these depletion-mode MRMs typically exhibit low PN junction tunability, thereby requiring higher modulation voltages in order to provide >6dB extinction ratios (ER). Furthermore, negative DC-biasing of the MRMs is necessary to maintain reverse-biased depletion-mode operation. In this work, a 525Gb/s hybrid-integrated MRM WDM transmitter is demonstrated that incorporates the following key advances: 1) an AC-coupled differential output driver that applies a 4.4Vpp-diff output-swing on the MRM while providing a tunable on-chip negative DC-bias; 2) a 2-tap non-linear digital FFE that compensates for optical-dynamics-induced bandwidth limitations; 3) a dynamic thermal tuning loop that stabilizes the MRM by minimizing thermally-induced wavelength fluctuations.

name of conference

  • 2015 IEEE International Solid-State Circuits Conference - (ISSCC) Digest of Technical Papers

published proceedings


author list (cited authors)

  • Li, H., Xuan, Z., Titriku, A., Li, C., Yu, K., Wang, B., ... Chiang, P. Y.

citation count

  • 15

complete list of authors

  • Li, Hao||Xuan, Zhe||Titriku, Alex||Li, Cheng||Yu, Kunzhi||Wang, Binhao||Shafik, Ayman||Qi, Nan||Liu, Yang||Ding, Ran||Baehr-Jones, Tom||Fiorentino, Marco||Hochberg, Michael||Palermo, Samuel||Chiang, Patrick Yin

publication date

  • January 2015