Lasers that can twist?
The light can be used as a type of "optical spanner" to or for encoding information in optical communicationsEuropost
When talking about lasers, it's common knowledge that it goes a straight line. However, that isn't the case for the new laser, developed by the University of Witwatersrand. Instead, researchers have demonstrated the world's first metasurface laser that produces "super-chiral light" - light with ultra-high angular momentum.
There are more strange quantities for lasers that go beyond wavelengths and intensity, which scientists have been exploring for years. Chirality, spirality, vorticity are being tested to make the laser beam effect a corkscrew motion. The reason for bending the laser would be to effectively improve optical data speeds by intensifying the laser even more. The problem with "twisted light" is that it is tough to detect. For years researchers on twisted lasers gone progressively and just a few weeks ago have made new advances on the field.
The laser developed by the University of Witwatersrand can make twisted light of utmost purity and angular momentum that uses metamaterials. Then another pair of experiments that were used to create a transmitter that can send vortex lasers as well as a receiver that will detect and classify the lasers with relative ease. The last experiment is most impressive since we mentioned that it's challenging to see the orbital angular momentum of an incoming photon.
"Because light can carry angular momentum, it means that this can be transferred to matter. The more angular momentum light carries, the more it can transfer. So you can think of light as an 'optical spanner'," Professor Andrew Forbes from the School of Physics at the University of the Witwatersrand (Wits) in Johannesburg, South Africa, who led the research. "Instead of using a physical spanner to twist things (like screwing nuts), you can now shine light on the nut and it will tighten itself."