Title:
|
Knotting fractional-order knots with the polarization state of light
|
Author:
|
Pisanty, Emilio; Jiménez Machado, Gerard; Vicuña Hernández, Verónica; Picón, Antonio; Celi, Alessio; Pérez Torres, Juan; Lewenstein, Maciej
|
Other authors:
|
Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions; Universitat Politècnica de Catalunya. FOTONICA - Grup de Recerca de Fotònica |
Abstract:
|
The fundamental polarization singularities of monochromatic light are normally associated with invariance under coordinated rotations: symmetry operations that rotate the spatial dependence of an electromagnetic field by an angle ¿ and its polarization by a multiple ¿¿ of that angle. These symmetries are generated by mixed angular momenta of the form J¿¿=¿L¿+¿¿S, and they generally induce Möbius-strip topologies, with the coordination parameter ¿ restricted to integer and half-integer values. In this work we construct beams of light that are invariant under coordinated rotations for arbitrary rational ¿, by exploiting the higher internal symmetry of ‘bicircular’ superpositions of counter-rotating circularly polarized beams at different frequencies. We show that these beams have the topology of a torus knot, which reflects the subgroup generated by the torus-knot angular momentum J¿, and we characterize the resulting optical polarization singularity using third- and higher-order field moment tensors, which we experimentally observe using nonlinear polarization tomography. |
Abstract:
|
Peer Reviewed |
Subject(s):
|
-Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Telecomunicació òptica::Fotònica -Photonics -Nonlinear optics -Optical physics -Optical techniques -Other photonics -Fotònica |
Rights:
|
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
|
Article - Submitted version Article |
Share:
|
|