Formation of arrayed holes on metal foil and metal film by multibeam interfering femtosecond laser beams

We report on an optical interference method to fabricate arrayed holes on metal nickel foil and aluminum film deposited on glass substrate by means of five-beam interference of femtosecond laser pulses. Optical microscope and scanning electron microscope observations revealed that arrayed holes of micrometer-order are fabricated on both metal foil and metal film. The present technique allows one-step, large-area, micrometer processing of metal materials for potential industrial applications.