Enhancement of debris attachment in phase-shifted ultrashort-pulse laser ablation

A 130fs laser pulse in which half of beam cross-section is phase-shifted regarding the other half carry out enhancement of debris attachment along diameter and periodical deposition corresponding to intensity variation due to Fresnel diffraction. The phase-shifted ultra-short laser pulsed was used to ablate the metallic targets. The phase shift is accomplished by using a phase-edge mirror with a step of Al coating with a height of a quarter wavelength of laser light. An abrupt intensity change was obtained by the phase-shift.