Topological Shaping of Light by Closed-Path Nanoslits

Etienne Brasselet (1) , Gediminas Gervinskas (2, 3) , Gediminas Seniutinas (2, 3) , Saulius Juodkazis (2, 3)

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine
2 Centre for Micro-Photonics
3 MCN - Melbourne Centre for Nanofabrication

We propose a discrete set of continuous deformation of a circular nanoslit to generate and control optical vortices at the microscopic scale. The process relies on the interplay between the spin and orbital angular momentum degrees of freedom of light mediated by appropriate closed-path nanoslits milled on a thin gold film. Topological shaping of light is experimentally demonstrated in the visible domain. Moreover, all experimental observations are quantitatively validated by a simple model that takes into account the transverse manipulation of the optical phase via the space-variant form birefringence of subwavelength slits.

Mots clés: Wave optics; Optical angular momentum and its quantum aspects; Birefringence polarization

Domaines: Optique [physics.optics]

Etienne Brasselet, Gediminas Gervinskas, Gediminas Seniutinas, Saulius Juodkazis. Topological Shaping of Light by Closed-Path Nanoslits. Physical Review Letters, 2013, 111 (19), pp.193901. ⟨10.1103/PhysRevLett.111.193901⟩. ⟨hal-00880432⟩