Focusing of Azimuthally Polarized Hyperbolic-Cosine-Gaussian Beam

X.M Gao,S.L Zhuang,M.Y Gao,H.M Guo,J Wang,S Hu

doi:10.4236/eng.2010.22018

Abstract

The focusing properties of azimuthally polarized hyperbolic-cosine-Gaussian (ChG) beam are investigated theoretically by vector diffraction theory. Results show that the intensity distribution in focal region of azimuthally polarized ChG beam can be altered considerably by decentered parameters, and some novel focal patterns may occur for certain case. On increasing decentered parameters, ring shape of focal pattern can evolve into four-peak focal pattern, and azimuthal field component affects focal pattern more significantly than radial field component. Optical gradient force is also calculated to show that the focusing properties may be used in optical tweezers technique.

Highlights

Laser beams with cylindrical symmetry in polarization have attracted many researchers recently for their interesting properties and applications
Results show that the intensity distribution in focal region of azimuthally polarized ChG beam can be altered considerably by decentered parameters, and some novel focal patterns may occur for certain case
On increasing decentered parameters, ring shape of focal pattern can evolve into four-peak focal pattern, and azimuthal field component affects focal pattern more significantly than radial field component

Summary

Introduction

Laser beams with cylindrical symmetry in polarization have attracted many researchers recently for their interesting properties and applications. These beams are called cylindrical vector beams and can be generated by active or passive methods [1,2,3,4]. To investigate focusing properties of this kind of light beam with azimuthally polarized distribution is very interesting, which may deepen understanding of its properties and expand application. The focusing properties of the azimuthally polarized hyperbolic-cosine-Gaussian (ChG) beam are investigated theoretically by vector diffraction theory.

Principle of the Focusing Azimuthally Polarized ChG Beam

Results and Discussions

Conclusions