Fig. 1: Polarization-independent Surface Nanostructuring.

a Schematic of polarization-independent nanostructuring in far field via microsphere by MHz femtosecond laser irradiation. b SEM and c AFM images of polarization-independent nano-lines created at a laser fluence of 0.14 mJ cm⁻² and a scanning speed of 150 μm s⁻¹. d Corresponding cross-sectional profiles obtained by AFM measurement