Ultrafast Laser Surface Nanostructuring with Programmable Temporal Polarization Shaping

Programmable femtosecond polarization pulse shaping has emerged as a powerful control tool across various fundamental and applied research fields driven by light, including quantum control, nonlinear optics, and ultrashort pulse laser technology, [1]–[3]. we explore here the generation of novel nanostructures self-organized under light using ultrafast laser pulses with time-domain polarization synthesis. The ultrafast temporal polarization shaping system enables precise design the polarization ellipticity and the orientation of the principal axes distributed in time-domain by using a programmable two-layer liquid crystal display (LC-SLM) inside a Fourier domain zero-dispersion compressor [4], [5], By shaping and recombining the orthogonal components of the incident laser field, we achieve temporally tailored polarization dynamics at the optical cycle. We focus on the specific case of surface laser-induced periodic structures. Generally, the generation of laser-induced periodic patterns by ultrafast laser pulses relies on the interference of incident and scattered light [6] along the interfaces. Evanescent patterns of light drive matter alignment and redistribution in relation to the laser electric field, therefore a dynamic laser polarization can play a remarkable role in controlling nanostructuring. Using Ti metal surfaces, we demonstrate that engineered time-dependent polarization significantly influences the formation of nanostructures. Specifically, we show that customized vectorial pulse shapes and sequences with variable polarization states across the pulse envelopes can profoundly impact the resulting nanostructures, opening new possibilities for advanced laser based material processing.