Shaping twisted light with atom-thin crystals

Los Alamos scientists have discovered a way to precisely control twisted beams of light — known as optical vortices — at the ultimate limit of material dimensionality. By doing so, they can adjust not only the light’s spectrum but also its topology, all at the nanoscale. The journal ACS Nano featured the work on its cover.
 
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Why this matters: Twisted light carries unique properties that could be used to pack more information into optical communication systems, enable more resilient quantum key distribution and allow for higher-dimensional quantum computing.
 
How they did it: The team’s method uses single-layer materials called van der Waals crystals.

• The team mixed multiple laser pulses in a two-dimensional quantum material, producing new twisted vortex light through nonlinear effects such as difference-frequency generation, sum-frequency generation and four-wave mixing. 
• The atomic thinness of the crystals makes it possible to control both the spectrum and the elementary structural properties of the generated vortex light field across a wide spectrum in an ultracompact platform, beyond the limits of traditional bulk materials.
• The work leverages Los Alamos’ experimental and theoretical expertise in nonlinear optics, ultrafast spectroscopy and 2D quantum materials.
   
  Funding: Laboratory Directed Research and Development program at Los Alamos, DOE NNSA Minority Serving Institution Partnership Program and DOE NNSA Laboratory Residency Graduate Fellowship. Work was primarily performed at the Center for Integrated Nanotechnologies, an Office of Science user facility. 

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