CO2 laser-produced ripple patterns on NixP1−x surfaces

Abstract

When CO₂‐laser pulses of ∼50 ns duration and intensity of ∼100–500 MW/cm² are incident upon Ni_xP_1−x surfaces in oxygen‐containing atmospheres, distinctive ’’ripple’’ patterns are etched into the surfaces. The ripple wave fronts are normal to the E field and vary in spacing from ∼λ_laser at normal incidence to ∼0.5λ_laser for π polarization at grazing incidence.