Laser-induced Microplasma as Effective Tool for Phase Elements Fabrication on Amorphous and Crystalline Materials

Surface precision processing of Iceland spar and fused silica is shown experimentally by laser-induced microplasma action. The optimal regimes allowed to control the relief depth up to similar to 14 mu m with the step of 50 nm are achieved and discussed. Two types of optical elements (random phase plate and spiral phase plate) are fabricated and tested in laser setups, to change initial intensity distribution (Gaussian) to flat-top and annular, consequently. Flap-top distribution characterized by low speckle modulation, i.e. high quality. The annular distribution corresponds to classical concepts.