Researchers at the University of California have created the first 500 Gigahertz (GHz) photon switch, a feat made possible by advances in the control of a strong optical beam using just three protons.
The latest development opens the way to a new class of sensitive receivers which are capable of operating at very high rates, and faster photon sensors and optical processing devices, according to the scientists.
"Our switch is more than an order of magnitude faster than any previously published result to date," said UC San Diego electrical and computer engineering professor Stojan Radic.
"That exceeds the speed of the fastest lightwave information channels in use today."
To build the new switch, the team developed techniques capable of resolving "sub-nanometer" variations in the core of the fibre, which allowed them to manage dispersion over long fibre lengths.
"This was critical because local fiber dispersion varies substantially, even with small core fluctuations, and until recently, control of such small variations was not considered feasible, particularly over long device lengths," the research paper said.
The UC San Diego scientists were then able to control a Watt-scale laser beam using just three photons at a speed exceeding 500 GHz.
To characterise the fibre, the team measured sub-nanometre core variations over many kilometres of fibre to build a "nanoscale signature library".
"From there, they identified a specific core fluctuation profile that would correspond to the maximum depletion of the photon pump. Once the calculation yielded a unique core variation profile for a length of fibre, the scientists combined two distinct fibre sections from the core fluctuation library with the same variation profile," the paper said.
