Paola Galli | Searcharxiv

arXiv2020

High-speed double layer graphene electro-absorption modulator on SOI waveguide

We report on a C-band double layer graphene electro-absorption modulator on a passive SOI platform showing 29GHz 3dB-bandwith and NRZ eye-diagrams extinction ratios ranging from 1.7 dB at 10 Gb/s to 1.3 dB at 50 Gb/s. Such high modulation speed is achieved thanks to the quality of the CVD pre-patterned single crystal growth and transfer on wafer method that permitted the integration of high-quality scalable graphene and low contact resistance. By demonstrating this high-speed CVD graphene EAM modulator integrated on Si photonics and the scalable approach, we are confident that graphene can satisfy the main requirements to be a competitive technology for photonics.

physics.app-ph↗

arXiv2013

Graphene Based Optical Phase Modulation

In this paper we report phase modulation obtained by inducing a capacitive charge on graphene layers embedded in the core of a waveguide. There is a biasing regime in which graphene absorption is negligible but large index variations can be achieved with a voltage-length product as small as $V_π\,L_π\simeq 0.04 $\,V\,cm . Examples of phase induced changes are computed for straight waveguides and for microring resonators showing the possibility to implement several optoelectronic functionalities as modulators, tunable filters, and switches.

physics.optics↗