Generation of zero-order Bessel beams with Fabry-Perot interferometer

A new concept for generating zero order Bessel beams was studied. A point source illuminated a Fabry-Perot etalon, which produced a concentric interference ring system in front of an imaging lens.If the lens aperture was adjusted so that it transmitted the first ring only and blocked all others, a zero order Bessel bean was generated beyond the lens. The spatial intensity distribution beyond the lens was calculated numerically using a wave optical model. The calculated and measured axial intensity distributions were compared. An approximate analytical expression was derived to describe the radial intensity distribution in planes perpendicular to the optical axis.