Anomalous surface transformations in crystalline silicon induced by subpicosecond laser pulses

Abstract
Surface transformations in crystalline silicon are investigated, using 400 fs laser pulses, at intensities just above the melting threshold. Anomalous changes of surface heights are observed, and they are enhanced for shorter pulses. These experimental results are well understood with a picture that shock stress generated by the ultrashort pulse excitation causes anomalous surface transformations of crystalline silicon.