Investigation of Periodic Microstructure Induced by 355 nm UV Polarized Laser on Polyimide Surface

We investigate a periodic microstructure induced by 355 nm ultraviolet polarized laser on polyimide surface and the dependence of the structures on laser parameters. Laser-induced periodic surface structures (LIPSS) of sub-micrometer size were generated on three kinds of polyimide films by a polarized Nd:YAG laser of 355 nm within a wide range of laser fluence. The chemical structure of polyimide, the film-making process, the number of laser pulses and the laser fluence greatly influenced the formation of LIPSS. The periodicity of LIPSS was decided by the wavelength, the incidence angle of the laser beam and the apparent refractive index of the material.