Patent ID: 9383597
Filing Date: 2016-07-05
CPC Classification: B23K,G02B,G02F

Claim Text:
1. A light modulation control method by use of a phase-modulation type spatial light modulator that inputs laser light thereto and then modulates the phase of the laser light so as to output the phase-modulated laser light and which controls light condensing irradiation onto a set light condensing point with the laser light by a modulation pattern to be presented in the spatial light modulator, the light modulation control method comprising: an irradiation condition acquiring step of acquiring, as an irradiation condition for the laser light, an incident pattern of the laser light to the spatial light modulator, a first refractive index n a light condensing condition setting step of setting, as a light condensing condition for the laser light, the number s an aberration condition deriving step of deriving an aberration condition that is caused by the first propagation medium and the second propagation medium, which have refractive indices different from each other, in the propagation of the laser light from the spatial light modulator to the light condensing point s; and a modulation pattern designing step of designing the modulation pattern to be presented in the spatial light modulator by taking into account the aberration condition derived in the aberration condition deriving step, wherein in the modulation pattern designing step, assuming a plurality of two-dimensionally arrayed pixels in the spatial light modulator and focusing on an effect on a light condensing state of the laser light at the light condensing point by a change in a phase value at one pixel of the modulation pattern to be presented in the plurality of pixels, the phase value is changed so that the light condensing state is brought closer to a desired state, and such phase value changing operations are performed on all pixels of the modulation pattern to thereby design the modulation pattern, and in evaluating the light condensing state at the light condensing point, a propagation function φ