Abstract
In this paper, the focusing properties of radially polarized modified Bessel-modulated Gaussian (RPMQBG) beam with quadratic radial dependence through a high numerical aperture (NA) lens are investigated, theoretically and numerically, using the vector diffraction theory model. The tight focusing properties are studied in great detail. The numerical simulation results show that the intensity distribution of the RPMQBG beam at the focal region of the numerical aperture can be changed considerably by the variation of the optical vortex beam topological charge 1 and by the high numerical aperture angle (NA).