A team of Australian researchers has created a revolutionary integrated nanophotonic chip that can manipulate the angular momentum (AM) of light to an unparalleled degree. This unique nanomanipulation of light could lead to the next generation of optical techniques, as well as reveal the secrets of the evolution and nature of black holes.
The new chip, created by Min Gu - a professor at RMIT University - and his team of scientists, opens up numerous doors for AM manipulation at a chip-scale in the generation, transmission, processing and recording of information.
Although light beams travel in roughly a straight line, they also spin and twist around their optical axis. The degree of this unique rotation is measured by the AM of light, a property that has attracted the attention of researchers in the recent years.
The biggest focus is on the potential of the AM of light to greatly expand the current capacity of optical fibres using parallel light channels, a process also referred to as "multiplexing."
Despite this potential, AM multiplexing has proved a challenge on the chip scale due to the lack of materials capable of sensing twisted light. Now, Gu and his team might have found a solution that can control both the spin angular momentum (SAM) and orbital angular momentum (OAM) of twisted light.
"By designing a series of elaborate nano-apertures and nano-grooves on the photonic chip, our team has enabled the on-chip manipulation of twisted light for the first time," he said. "The design removes the need for any other bulky interference-based optics to detect the AM signals."
"Our specially-designed nanophotonic chip can precisely guide AM data signals so they are transmitted from different mode-sorting nano-ring slits without losing any information," added Haoran Ren, lead author of the paper and Ph.D. candidate at Swinburne University of Technology.
In addition to its potential to provide a new platform for evolution in the big data industry, the manipulation of light by the nanophotonic chip could also offer a new way to shed light on black holes.
"Due to the fact that rotating black holes can impart OAM associated with gravitational waves, an unambiguous measuring of the OAM through the sky could lead to a more profound understanding of the evolution and nature of black holes in the universe," Gu said.
The findings were published online in the April 7 issue of Science.
