Huapu Pan

A 90nm CMOS integrated Nano-Photonics technology for 25Gbps WDM optical communications applications

The first sub-100nm technology that allows the monolithic integration of optical modulators and germanium photodetectors as features into a current 90nm base high-performance logic technology node is demonstrated. The resulting 90nm CMOS-integrated Nano-Photonics technology node is optimized for analog functionality to yield power-efficient single-die multichannel wavelength-mulitplexed 25Gbps transceivers.

Coupling modulation of microrings at rates beyond the linewidth limit

We demonstrate optical modulation rates exceeding the conventional cavity linewidth limit using a silicon coupling modulated microring. Small-signal measurements show coupling modulation was free of the parasitic cavity linewidth limitations at rates at least 6× the cavity linewidth. Eye diagram measurements show coupling modulation achieved data rates > 2× the rate attainable by conventional intracavity phase modulation. We propose to use DC-balanced encoding to mitigate the inter-symbol interference in coupling modulation. Analysis shows that coupling modulation can be more efficient than intracavity modulation for large output swings and high-Q resonators. Coupling modulation enables very high-Q resonant modulators to be simultaneously low-power and high-speed, features which are mutually incompatible in typical resonant modulators studied to date.

High-speed receiver based on waveguide germanium photodetector wire-bonded to 90nm SOI CMOS amplifier

The performance of a receiver based on a CMOS amplifier circuit designed with 90nm ground rules wire-bonded to a waveguide germanium photodetector is characterized at data rates up to 40Gbps. Both chips were fabricated through the IBM Silicon CMOS Integrated Nanophotonics process on specialty photonics-enabled SOI wafers. At the data rate of 28Gbps which is relevant to the new generation of optical interconnects, a sensitivity of -7.3dBm average optical power is demonstrated with 3.4pJ/bit power-efficiency and 0.6UI horizontal eye opening at a bit-error-rate of 10(-12). The receiver operates error-free (bit-error-rate < 10(-12)) up to 40Gbps with optimized power supply settings demonstrating an energy efficiency of 1.4pJ/bit and 4pJ/bit at data rates of 32Gbps and 40Gbps, respectively, with an average optical power of -0.8dBm.

Monolithically integrated silicon nanophotonics receiver in 90nm CMOS technology node

A monolithically-integrated germanium receiver is fabricated in the IBMs newly established 90nm CMOS-integrated nanophotonics technology node. Technology is promising for cost-effective 10Gbps to 28Gbps optical communications links operating within extended temperature range up to 95°C.

28 Gb/s silicon microring modulation beyond the linewidth Limit by coupling modulation

A silicon-on-insulator microring modulator with a linewidth of ~ 7 GHz is operated at 28Gb/s by modulation of the microring-bus waveguide coupler. The modulator was driven with pre-emphasized signals with a maximum swing of 1.5Vpp.

250 Gbps 10-channel WDM silicon photonics receiver

An ultra-compact 10-wavelength WDM echelle grating receiver is demonstrated with 250 Gbps data receiving capability on a footprint of 0.96 mm2. Less than 1 dB channel-to-channel sensitivity variation is obtained at 25 Gbps.

Breaking the conventional limitations of microrings

We demonstrate microring resonators with full tunability, modulation bandwidths exceeding the linewidth limit, and improved tolerance to wafer-scale variations. Novel device architectures and designs enable microrings to become more practical for integrated photonics.