Researchers have discovered that light can possess a new property, self-torque. This discovery could open up exciting possibilities in light-related applications including smart phones and hard drives.
Light beams with self-torque possess an angular momentum that changes continuously in time. These beams can be naturally generated through the process of high-harmonic generation. They look like a croissant, containing over an octave of orbital angular momentum values along the light pulse.
In several experiments, the authors studied the unique properties of beams with self-torque. "This is the first time that anyone has predicted or even observed this new property of light," said Rego, the researchers’ team leader. "For example, we think we can modulate the orbital angular momentum of light in the same way frequency is modulated in communications."