Open AccessExperimental generation of complex optical fields for diffraction limited optical focus with purely transverse spin angular momentum
Author(s) -
Jian Chen,
Chenhao Wan,
Lingjiang Kong,
Qiwen Zhan
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.008966
Subject(s) - physics , optics , diffraction , polarization (electrochemistry) , angular momentum , lens (geology) , electric field , transverse plane , numerical aperture , cardinal point , optical tweezers , optical axis , dipole , focal point , entrance pupil , quantum mechanics , pupil , wavelength , chemistry , structural engineering , engineering
We demonstrate a method to generate complex optical fields at the pupil plane of a high numerical aperture (NA) objective lens for the creation of diffraction limited optical focus with purely transverse spin angular momentum. The complex optical fields are analytically deduced through reversing the radiated patterns from two electric dipoles, which are located at the focal point of the high NA lens and oscillate respectively in x- and z- directions with phase difference of π/2. The derived fields can be experimentally created with a vectorial optical field generator. Using the Richard-Wolf vectorial diffraction theory, the electric fields within the focal region are calculated to evaluate the intensities and polarization distributions of the tightly focused beams corresponding to both the theoretical and experimentally generated pupil fields and the results clearly demonstrate the validity of the proposed technique.