Electromagnetically induced transparency of structured light

Dr Sonja Franke-Arnold, Physics & Astronomy, University of Glasgow

Friday 24 January 2014, 1500-1600
C1 Physics Building

How does holographically shaped light interact with cold atoms? Scattering of light by atoms, and its absorption, is usually sensitive only to the intensity profile of a light beam. By simultaneously driving multiple atomic transitions, it is possible to modify the absorption profile of a "signal" laser due to the presence of a second "control" beam, an effect known as EIT.

We report first our observations of EIT with holographically shaped light beams, namely light carrying orbital angular momentum. The shaped signal and control light modify the atomic populations, generating spatially varying atomic dark states. This generates a spatially varying transparency of the atoms, with a profile encoded onto the transmitted light. The whole process therefore converts optical phase information into intensity information.