A light application apparatus includes an optical modulation element
provided with a plurality of phase steps, a light beam which is entered
into the optical modulation element being phase-modulated by the phase
steps and exits from the optical modulation element as a light beam
having a first light intensity distribution. An optical system is
arranged between the optical modulation element and an predetermined
plane. The optical system divides the phase-modulated light beam into at
least two light fluxes having second and third light intensity
distributions and different optical characteristics from each other, and
projects a light beam including the divided two light fluxes, the light
intensity distributions of the projected light fluxes being combined with
each other, so that the projected light beam has a fourth light intensity
distribution with an inverse peak shape on the predetermined plane and
enters the predetermined plane. The first to fourth light intensity
distributions are different from each other on the predetermined plane.