Graphene photonic chip could enable lower power telecommunications
1 min read
Researchers in the US have demonstrated optical nonlinear behaviour in graphene that they say could lead to new developments in optical interconnects and low power photonic integrated circuits.
The team at Columbia Engineering created a hybrid graphene-silicon device whose optical nonlinearity enabled system parameters such as transmittance and wavelength conversion to change with input power level.
"We have been able to demonstrate and explain the strong nonlinear response from graphene, which is the key component in this new hybrid device," said Tingyi Gu, a PhD candidate in electrical engineering. "Showing the power efficiency of this graphene-silicon hybrid photonic chip is an important step forward in building all optical processing elements that are essential to faster, more efficient, modern telecommunications."
By optically driving the electronic and thermal response in the chip, the researchers observed that they could generate a radio frequency carrier on top of the transmitted laser beam and control its modulation with the laser intensity and colour. Using different optical frequencies to tune the radio frequency, they found that the graphene-silicon hybrid chip achieved radio frequency generation with a resonant quality factor more than 50 times lower than what is normally achieved in silicon.
"We generated new optical frequencies through nonlinear mixing of two electromagnetic fields at low operating energies, allowing reduced energy per information bit," commented professor of mechanical engineering, Chee Wei Wong. "This allows the hybrid silicon structure to serve as a platform for all optical data processing with a compact footprint in dense photonic circuits."
