| dc.description.abstract | Ultra wide-band optical channel’s insensitivity to frequency and communication distance makes it suitable to support ever-increasing data-rate, while electrical copper channel is no longer a solution. Optical transceiver based on micro-ring resonator is an effective approach bridging optical channel’s THz bandwidth and electrical circuit’s GHz running speed, but has increased design complexity.
This dissertation presents three designs focusing on power-efficient short-reach optical communication up to hundreds of meters, including one wire-boned optical receiver and two 3D-integrated optical transceivers. TIA with a multi-stage amplifier is proposed to reduce optical receiver’s noise and improve its sensitivity, without extra power and silicon area. Clocking, transmitter and micro-ring resonant wavelength stabilization are also discussed to make a complete power-efficient optical transceiver.
Combining all noise reduction techniques, the 12.5 Gb/s optical receiver fabricated in 28 nm CMOS technology achieves 0.11 pJ/bit power efficiency and -10.7 dBm OMA sensitivity at 10−12 BER with a 0.6 A/W wire-bonded PD. Power efficiency improves by 3.6X while normalized OMA sensitivity improves by 3.2 dB, compared to conventional TIA using a single-stage amplifier. Its minimal silicon area without on-chip inductors makes it suitable for high bandwidth-density applications.
Further improvement is achieved in the 32-channel optical transceiver fabricated in 12 nm CMOS technology, with co-designed optical devices and 3D integration. Optical transmitter has 157 fJ/bit power efficiency at 18 Gb/s. The measured optical receiver power efficiency of 84.8 fJ/bit and -17.0 dBm OMA sensitivity at 25 Gb/s is the state-of-the-art result to our best knowledge. Normalized OMA sensitivity is second only to power-hungry design using DFE, with 18.75X better power efficiency.
The 20-channel design has been taped-out in 22 nm CMOS technology, with simulated 179 fJ/bit overall power efficiency at 500 Gb/s aggregate data rate. 3D-integrated optical transceiver incorporates MOS-capacitor modulator transmitter with DVFS and multi-phase clock generated by DLL for less power. Electrostatic micro-ring resonant wavelength stabilization is included to eliminate high-power heater-based tuning. | |
