Via www.sci-news.com: An international team of physicists has theoretically predicted
and experimentally generated light beams with a new property that they
call the self-torque of light. The discovery, reported in the journal Science, could help us understand physics in binary black holes as well as how to control dynamics in molecules and nanostructures.
Two time-delayed infrared vortex laser pulses (upper-left) impinge on a gas target to generate coherent, EUV light with a time-dependent orbital angular momentum (right): the self-torque of light. Image credit: Kevin Dorney, JILA.
Light beams carry both energy and momentum, which can exert a small but detectable pressure on objects they illuminate.
In 1992, it was
realized that light can also possess
orbital angular momentum (OAM) when the spatial shape of the beam of light rotates — or twists — around its own axis.
Although not visible to the naked eye, the presence of OAM can be revealed when the light beam interacts with matter.
OAM beams are enabling new applications in optical communications, microscopy, quantum optics, and microparticle manipulation.
To date, however, all OAM beams — also known as vortex beams — have been static; that is, the OAM does not vary in time...
Full text: http://www.sci-news.com/physics/self-torque-light-07340.html
