Focusing properties of radially polarized helico-conical Lorentz-Gauss beam with radial phase wavefront

Radially polarized helico-conical Lorentz-gauss beam with radial phase wavefront modulation can change the optical properties of the focal region in focusing optical system, which has tremendous research significance and application value in a host of territories, such as exotic optics, optical micromanipulation and so on. In this paper, by the utilization of the vector diffraction theory, the focusing properties of radially polarized helicon-conical Lorentz-Gauss beam with radial phase wavefront are investigated theoretically and numerically. Results show that focus shift is considerably influenced by changing the charge number m, eccentric parameter K, the numerical aperture NA and the radial phase parameter n, and simultaneously, unconspicious changes can be observed if we only alter the radial phase parameter m without the changes of m, K or the numerical aperture NA. (C) 2017 Elsevier GmbH. All rights reserved.