KEYWORDS: Axicons, Global system for mobile communications, Spatial coherence, Light, Optical engineering, Plutonium, Optical components, Monochromatic aberrations, Optical design, Electron beam lithography
In this paper, both backward and forward-type lens axicons illuminated by a Gaussian-Schell model (GSM) beam are studied. A numerical calculation is performed to investigate the axial intensity distribution of the focal segment. It is shown that when a backward-type lens axicon is illuminated with an appropriate beam radius and spatial coherence of the incident GSM beam, one can achieve a focal segment with uniform axial intensity. The rapid oscillation of the axial intensity can be reduced by the decreasing of spatial coherence. This method is very simple and efficient. A forward-type lens axicon illuminated by a GSM beam is also investigated.
We show that when a partially coherent beam with a Gaussian intensity distribution is focused by a lens, the intensity distribution near geometrical focus is strongly dependent upon the spatial coherence. Based on this, the desired intensity distribution near the focus can be generated by choosing appropriate form of spatial coherence. It is shown that the partially coherent flat-top intensity distribution near the geometrical focus or a partially coherent bottle beam can be produced by choosing appropriate forms of spectral degree of coherence. The influence of some parameters of the incident beams on the resultant beams near geometrical focus is investigated.