Fractional Derivative Analysis of Helmholtz and Paraxial-Wave Equations
  Fundamental rules and definitions of Fractional Differintegrals are outlined. Factorizing 1-D and 2-D Helmholtz equations four fractional eigenfunctions are determined. The functions exhibit incident and reflected plane waves as well as diffracted incident and reflected waves of the half-plane edge. They allow to construct the Sommerfeld half-plane diffraction solutions. Parabolic-Wave Equation (PWE, Leontovich-Fock) for paraxial propagation is factorized and differetial fractional solutions of Fresnel-integral type are derived. We arrived at two solutions, which are the mothers of known and new solutions. 
A. J. Turski, B. Atamaniuk and E. Turska