Analysis of the axial distribution of a tightly focused beam with different polarizations

The paper analyzes an axial distribution of the tightly focused laser beam with different polarizations. The beam is presented as a superposition of the vortex phase functions. An analytical solution for the each component of the electric field is obtained for the incident beam narrowed by a ring aperture of arbitrary width. Approximate analytical estimates for the axial distribution in elementary functions have been obtained also. This makes to easily analyze the nature of the intensity along the optical axis. The influence of weighted superposition of vortex phase functions in the incident beam and the type of polarization on the relative contributions of the different components of the electric field in the focal region of the optical axis is numerically investigated.