Scientists Tie Light into Knots

January 24, 2010 

Researchers have created optical beams with isolated optical vortex loops using holograms designed with knot theory. This work brings to light an application of a branch of abstract mathematics.

Natural and artificially created light fields in three-dimensional space contain lines of zero intensity, which are called optical vortices. The light around us is filled with these dark lines, even though we can't see them, said Mark Dennis (University of Bristol). 

He added that the study of knotted vortices had been initiated by Lord Kelvin in 1867 in a quest for an explanation of atoms. "This work opens a new chapter in that history,"Dennis said.

Colleague Miles Padgett (Glasgow University) said, ''The sophisticated hologram design required for the experimental demonstration of the knotted light shows advanced optical control, which undoubtedly can be used in future laser devices.''

Dennis, Padgett, Robert P. King, Barry Jack, and Kevin Holleran detailed it all in "Isolated Optical Vortex Knots", which appeared in Nature Physics (February 2010).

Source: Telegraph (Jan. 18, 2010)