The Gouy phase of Airy beams

The phase behavior of Airy beams is studied, and their Gouy phase is defined. Analytic expressions for the idea-lized, infinite-energy type beam are derived. They are shown to be excellent approximations for finite-energy beams generated under typical experimental conditions. © 2011 Optical Society of America OCIS codes: 050.1960, 350.5030. Beams that do not spread on propagation, so-called non-diffracting beams, have attracted considerable attention since they were discovered by Durnin et al. [1–3]. A spe-cial type of such beams are the Airy beams described by Berry and Balazs in the context of quantum mechanics [4]. These beams have the remarkable property that they “accelerate ” away from the original direction of propaga-tion. Airy beams are idealizations, because they carry an infinite amount of energy. Siviloglou and Christodoulides discussed how an exponentially modulated Airy function source would produce a finite-energy beam, which woul