Generation of multiple spherical spots with a radially polarized beam in a 4u0001 focusing system

摘要

We demonstrate the possibility of creating multiple spherical spots in a 4u0001 focusing system with a radiallynpolarized beam. Using spherical waves to expand the plane wave factor in the Richards–Wolf integral, it isnfound that a proper spatial modulation in the amplitude of the input field with radial polarization can formnmultiple spherical spots with a focusing system satisfying the Herschel condition. These spots are distributednsymmetrically about the focus on the optical axis with variable positions and intensities. Although we considernonly the case of three spherical spots in this paper, generalization to the multiple-spots case will present nondifficulty. © 2010 Optical Society of America