Periodic nanoscale structures on polyimide surfaces generated by temporally tailored femtosecond laser pulses

Abstract : Ultrashort laser pulses tailored on a picosecond time scale were employed to study the influence of different pulse durations and double pulses on the formation of ripples on polyimide. A strong dependence of the ripple formation on the pulse duration as well as the double pulse delay time could be explained in terms of thermal expansion of the polymer lattice correlated to a loss of long range order and polarisation memory.