2010-01-19

Tying light in knots

Clipped from: Physicists tie light in knots


Physicists Tie Light in Knots

ScienceDaily (Jan. 18, 2010) — The remarkable feat of tying light in knots has been achieved by a team of physicists working at the universities of Bristol, Glasgow and Southampton, UK, reports a paper in Nature Physics this week.

Clipped from: | LiveScience.com

By reflecting a laser beam from a specially designed hologram (shown here as the colored circle), physicists created knots of dark filaments (represented by the colored knot). Credit: Mark Dennis.


Physicists have twisted dark filaments into knots by using a laser beam and a computer-controlled hologram. The results have implications for the future laser devices. Credit: Mark Dennis.


Clipped from: Bristol University | News from the University | Knots

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Tying light in knots

Understanding how to control light in this way has important implications for laser technology used in wide a range of industries.
Dr Mark Dennis from the University of Bristol and lead author on the paper, explained: “In a light beam, the flow of light through space is similar to water flowing in a river.  Although it often flows in a straight line – out of a torch, laser pointer, etc – light can also flow in whirls and eddies, forming lines in space called ‘optical vortices’.
“Along these lines, or optical vortices, the intensity of the light is zero (black). The light all around us is filled with these dark lines, even though we can’t see them”.
Optical vortices can be created with holograms which direct the flow of light. In this work, the team designed holograms using knot theory – a branch of abstract mathematics inspired by knots in everyday life, such as those that occur in shoelaces and rope. Using these specially designed holograms they were able to create knots in optical vortices.
Sources:
  1. Physicists tie light in knots
  2. Twisted Physics: Scientists Create Light Knots | LiveScience
  3. Bristol University | News from the University | Knots
Related:
  1. Access : Isolated optical vortex knots : Nature Physics
  2. Mark Dennis : Home page
  3. University of Glasgow :: University news
  4. Optics group » Miles Padgett
  5. Light'sTwist.ppt - Powered by Google Docs