Study on the Compensation of Silicon Photonics-Based Modulators in DCI Applications

Naim Ben-Hamida1,a, Mahdi Parvizi1,b, Ahmad Abdo2,c, Claude D'Amours2,d, Xueyang Li3,e, David V. Plant3,f and Md Samiul Alam3,g

1 Ciena Corporation Ottawa, Canada
anbenhami@ciena.com
bmparvizi@ciena.com
2 School of Electrical Engineering and Computer Science University of Ottawa Ottawa, Canada
caabdo013@uottawa.ca
dcdamours@uottawa.ca
3 Department of Electrical and Computer Engineering McGill University Montreal, Canada
exueyang.li@mail.mcgill.ca
fdavid.plant@mcgill.ca
gmd.samiul.alam@mail.mcgill.ca

ABSTRACT

For next generation high speed optical coherent systems, digital pre-emphasis filters are essential as they can precompensate for the transmitter frequency response and mitigate receiver noise enhancement. However, the downside of using full pre-emphasis to completely pre-compensate for the low bandwidth transmitter is that it increases the signal peak-toaverage power ratio (PAPR), thus posing a higher effective number of bits (ENoB) requirement for the digital to analog converter (DAC) and increases optical modulation loss. In this paper, we study the impact of partial pre-emphasis filters on signal PAPR and show how partial pre-emphasis reduces DAC ENoB requirements and MZM modulation loss. Our proposed scheme reduced the DAC ENoB requirement from 5 to 4.5 bits at the same implementation SNR. This enables a lower optical module power through the reduction of DAC and driver amplifier (DA) power. The experimental results, for single-pol case for a partial preemphasis filter, showed that the system bandwidth can be extended from 10GHz to 20GHz and tolerate a 6dB loss for a 0.4dBQ penalty factor, and a 0.8dB PAPR reduction.

Keywords: Pre-emphasis, Optical Pluggable, Coherent Transceivers, Data-Center Interconnect, Silicon Photonics.



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