High performance integrated graphene electro-optic modulator at cryogenic temperature

TL;DR

This paper demonstrates a graphene-based electro-optic modulator operating at cryogenic temperatures with a bandwidth exceeding room temperature, highlighting its potential for low-temperature optical interconnects.

Contribution

The authors present a high-performance integrated graphene electro-optic modulator with significantly improved bandwidth at cryogenic temperatures, surpassing previous limitations of temperature-dependent modulators.

Findings

Bandwidth at 4.9 K is 14.7 GHz, higher than 12.6 GHz at room temperature.

Intrinsic RC-limited bandwidth is 200 GHz at 4.9 K.

Performance limited by contact resistance, not material properties.

Abstract

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, since 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.