Nanophotonics (Sep 2020)

High-performance integrated graphene electro-optic modulator at cryogenic temperature

  • Lee Brian S.,
  • Kim Bumho,
  • Freitas Alexandre P.,
  • Mohanty Aseema,
  • Zhu Yibo,
  • Bhatt Gaurang R.,
  • Hone James,
  • Lipson Michal

DOI
https://doi.org/10.1515/nanoph-2020-0363
Journal volume & issue
Vol. 10, no. 1
pp. 99 – 104

Abstract

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High-performance integrated electro-optic modulators operating at low temperature are critical for optical interconnects in cryogenic applications. Existing integrated modulators, however, suffer from reduced modulation efficiency or bandwidth at low temperatures because they rely on tuning mechanisms that degrade with decreasing temperature. Graphene modulators are a promising alternative because graphene’s intrinsic carrier mobility increases at low temperature. Here, we demonstrate an integrated graphene-based electro-optic modulator whose 14.7 GHz bandwidth at 4.9 K exceeds the room temperature bandwidth of 12.6 GHz. The bandwidth of the modulator is limited only by high contact resistance, and its intrinsic RC-limited bandwidth is 200 GHz at 4.9 K.

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