It’s all for one and one for all as an Israeli-German team led by Distinguished Prof. Mordechai (Moti) Segev has revealed, in a recent paper in Science, how to force an array of tiny vertical cavity lasers to act together as a single coherent laser – a highly powerful laser network the size of a grain of sand.
Cell phones, medical devices, sensors, and fiber optic networks all use Vertical-Cavity Surface-Emitting Lasers (VCSELs) – semiconductor lasers of miniscule size of a few microns, which strictly limits power output. For years, scientists have sought to enhance the power emitted by semiconductor lasers by combining many tiny VCSELs and forcing them to act as a single coherent laser, but with limited success. Segev’s breakthrough uses a different scheme: it employs a photonic topological insulator platform, with a unique geometrical arrangement of VCSELs on the chip that forces the light to flow in a specific path.
WE WERE A BUCH OF LUNATICS SEARCHING FOR SOMETHING THAT WAS CONSIDERED IMPOSSIBLE. AND NOW WE HAVE ADE A LARGE STEP TOWARDS REAL TECHNOLOGY THAT HAS MANY APPLICATIONS.
– Distinguished Prof. Moti Segev
This groundbreaking research demonstrates that it is theoretically and experimentally possible to combine VCSELs to achieve a powerful, robust, and efficient coherent laser, paving the way towards new applications for medical devices, communications, and a variety of real-world applications.
“It is fascinating to see how science evolves,” says Segev, the Shillman Distinguished Professor of Physics and Electrical Engineering. “Back in 2015, when we started, nobody believed it was possible, because the topological concepts known at that time were limited to systems that cannot have gain. Yet all lasers require gain. So topological insulator lasers stood against everything known at the time.”
TOPOLOGY, ORIGINALLY A BRANCH OF MATHEMATICS, HAS EMERGED AS A REVOLUTIONARY NEW TOOLBOX FOR CONTROLLING, STEERING AND IMPROVING LASER PROPERTIES.
– Prof. Sebastian Klembt, University of Würzburg
The international team included Segev’s PhD student Alex Dikopoltsev and Klembt’s PhD student Tristan H. Harder.