Analyses of a radially polarized vector beam in the source region

摘要

The contribution of propagating and evanescent waves to a radially polarized beam is separated by the vector angular spectrum method, and the characteristics of a radially polarized beam close to the source in the nonparaxial regime are investigated. The analytical expressions for the propagating and evanescent waves of a radially polarized beam in the source region have been obtained without any approximation. The analyses show that the waist width and the order n of the Laguerre polynomial play an important role in the behavior of the evanescent waves. The influence of the evanescent waves on the radially polarized beam is discussed by the numerical results.