“…[49,50] Later, alternative methods of production have been proposed, where less expensive optical elements, like cylindrical lenses, replace the rather expensive spatial phase modulators, [52] or Airy patterns are directly produced. [53,54] As to the latter, in fact, on the basis of the approximate expression of the Airy function Ai(ξ ) ξ −1/4 e i 2 3 ξ 3/2 , [40,45,47] Airy beams have been directly generated by neglecting the amplitude dependence and encoding only the 3/2 phase pattern e iCξ 3/2 onto a liquid crystal display. [54] Figure 9 shows the contourplots of the squared amplitude of the wave function ψ (A,ε) (ξ, τ ) evolving from (50) under the Salpeter equation (32).…”