Open AccessAchievement of needle-like focus by engineering radial-variant vector fields
Author(s) -
Bing Gu,
Jialu Wu,
Yang Pan,
Yiping Cui
Publication year - 2013
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.21.030444
Subject(s) - paraxial approximation , optics , polarization (electrochemistry) , physics , physical optics , focus (optics) , ray , optical power , electric field , radius , nonlinear optics , laser , computer science , quantum mechanics , beam (structure) , chemistry , computer security
We present and demonstrate a novel method for engineering the radial-variant polarization on the incident field to achieve a needle of transversally polarized field without any pupil filters. We generate a new kind of localized linearly-polarized vector fields with distributions of states of polarization (SoPs) describing by the radius to the power p and explore its tight focusing, nonparaxial focusing, and paraxial focusing properties. By tuning the power p, we obtain the needle-like focal field with hybrid SoPs and give the formula for describing the length of the needle. Experimentally, we systematically investigate both the intensity distributions and the polarization evolution of the optical needle by paraxial focusing the generated vector field. Such an optical needle, which enhances the light-matter interaction, has intriguing applications in optical microma-chining and nonlinear optics.