Reflective Spin-Orbit Geometric Phase from Chiral Anisotropic Optical Media

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

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine

We report on highly reflective spin orbit geometric phase optical elements based on a helicity preserving circular Bragg reflection phenomenon. First, we present a dynamical geometric phase experiment using a flat chiral Bragg mirror. Then, we show that shaping such a geometric phase allows the efficient spin orbit tailoring of light fields without the need to fulfill any condition on birefringent phase retardation, in contrast to the case of transmission spin orbit optical elements. This is illustrated by optical vortex generation from chiral liquid crystal droplets in the Bragg regime that unveils spin orbit consequences of the droplet's curvature. Our results thus introduce a novel class of geometric phase elements " Bragg Berry " optical elements.

Domaines: Optique [physics.optics]

Mushegh Rafayelyan, Georgiy Tkachenko, Etienne Brasselet. Reflective Spin-Orbit Geometric Phase from Chiral Anisotropic Optical Media. Physical Review Letters, 2016, 116 (25), pp.253902 (1-5). ⟨10.1103/PhysRevLett.116.253902⟩. ⟨hal-01346264⟩