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Abstract Jean-Pierre Galaup et Laurence Pruvost

Twisted light exchanged with atoms and optical tweezers.

Laurence Pruvost, Jean-Pierre Galaup
Laboratoire A. Cotton, CNRS, Univ Paris-Sud, ENS-Cachan, Univ Paris-Saclay, bat 505, campus d'Orsay, 91405, Orsay.

A vortex beam -or twisted beam- characterized by a topological point on its  wavefront is also carrying an orbital angular momentum (OAM). This  quantized quantity is used in many contexts, as quantum computing or telecommunication. In Laboratoire A. Cotton we focus the studies on the exchange between optical vortices and atoms (cold or not) and with mesoscopic objects.

For this talk L. Pruvost will  present vortex generation and detection and experiments on the OAM  transfer via atomic ensembles. Using nonlinear processes, and with adequate configurations of the input light beams, storing/retrieval of OAM  and amplification in the output vortex have  been demonstrated [1,2,3]. In a recent experiment on Rb,  the OAM  transfer has been realized with a frequency conversion.

In a second part, J.- P. Galaup will present experiments and results on objects trapped in optical tweezers [4], and manipulated by spin angular momentum (SAM)  and on the associated future developments.

[1] Modes de Laguerre-Gauss et canalisation d'atomes froids, C. Cabrera-Guittierez, thèse de doctorat, univ Paris-Sud, décembre 2014.
[2] Storage of orbital angular momenta of light via coherent population oscillation, A.J.F. de Almeida, S. Barreiro, W.S. Martins, R.A. de Oliveira, D. Felinto, L. Pruvost, J.W.R. Tabosa, Opt. lett. 40 , 2545-2548 (2015).
[3] Narrow band amplification of light carrying orbital angular momentum, G.C. Borba, S. Barreiro, L. Pruvost, D. Felinto, J.W.R. Tabosa, Opt. Expr. 24, 10078-10086 (2016).
[4] High rotation speed of single molecular microcrystals in an optical trap with elliptically polarized light, M. Rodriguez-Otazo, A. Augier-Calderin, J.-P. Galaup, J.-F. Lamère, and S. Fery-Forgues, Appl. Opt.,48, 2720 (2009).