Materials science

Photodetector

Optoelectronics

Detector

Silicon photonics

Telecommunications

Physics

Optical power

Nanotechnology

CMOS

Optics

Gigabit

Amplifier

Graphene

Computer science

Bandwidth (computing)

Laser

Photonics

Nature Communications

One of the main challenges of next generation optical communication is to increase the available bandwidth while reducing the size, cost and power consumption of photonic integrated circuits. Graphene has been recently proposed to be integrated with silicon photonics to meet these goals because of its high mobility, fast carrier dynamics and ultra-broadband optical properties. We focus on graphene photodetectors for high speed datacom and telecom applications based on the photo-thermo-electric effect, allowing for direct optical power to voltage conversion, zero dark current, and ultra-fast operation. We report on a chemical vapour deposition graphene photodetector based on the photo-thermoelectric effect, integrated on a silicon waveguide, providing frequency response >65 GHz and optimized to be interfaced to a 50 Ω voltage amplifier for direct voltage amplification. We demonstrate a system test leading to direct detection of 105 Gbit s-1 non-return to zero and 120 Gbit s-1 4-level pulse amplitude modulation optical signals.

Photo thermal effect graphene detector featuring 105 Gbit s−1 NRZ and 120 Gbit s−1 PAM4 direct detection