“…In recent years, the properties of beams focused by an NA lens system have attracted more attention and extensive investigation, because of their fascinating features and wide potential applications in modern micro-lithography optical data storage, microscopy, material processing, and manipulation of particles (Rydberg 2008, Foreman and Torok 2009, Bokor and Davidson 2007, Walker and Milster 2001, Helseth 2002. Moreover, the properties of optical vortex beams have received substantial interest from many researchers (Zhan and Leger 2002, Hricha et al 20021a, Hricha et al 2021b, Hricha et al 20021c, Hricha et al 2021d, El Halba et al 2021, Milster 2001, Rao et al 2009.…”