Spin-orbit optomechanics of optically levitated chiral Bragg microspheres

Georgiy Tkachenko (1) , Mushegh Rafayelyan (1) , Etienne Brasselet (1)

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine

We explore the spin-orbit nature of the optical torque exerted on chiral liquid-crystal microspheres exhibiting circular Bragg reflection. Experimental investigation relies on the direct optomechanical observation of spinning liquid-crystal droplets immersed in water and held in a circularly polarized laser levitator. More generally, we anticipate that the total angular momentum transfer per photon may depart from the commonly assumed spin-only ±2¯ h contribution, when the topological features of the illuminated microsphere are taken into account.

Domaines: Optique [physics.optics]

Georgiy Tkachenko, Mushegh Rafayelyan, Etienne Brasselet. Spin-orbit optomechanics of optically levitated chiral Bragg microspheres. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2017, 95 (5), pp.053839. ⟨10.1103/PhysRevA.95.053839⟩. ⟨hal-01542702⟩