New evolution in interfering femtosecond laser processing

In interfering femtosecond laser processing, an interference pattern is transferred to material surface, and matrix with a certain unit structure can be generated in a single shot of laser irradiation. So, a metamaterial consist of meta-atoms can be fabricated by metallic thin film processing. The structure of it can be designed by controlling the phase shift and variation of amplitude between interfering laser beams. In this paper, interference patterns are summarized in the case of four and six beam correlation. In addition, the structural changes with different processing thresholds are investigated in detail.