Mechanism for self-organization of periodic structures on a metal surface by femtosecond laser pulses

The authors have presented the model to interpret the grating spaces for the first time. For femtosecond-pulse laser matter interactions, the laser produced plasma scale length is short enough for the plasma to form a surface. On such a surface the surface plasma waves may be excited. However the direct excitation by the incident laser cannot produce the plasma wave of which wavelength is as short as that of the produced periodic grating structures. The authors have proposed a parametric process for the laser light to be decayed into the surface plasma wave and light, which is in general called stimulated Raman for bulk plasmas. In this process the wavelength of the plasma wave depends on plasma frequency.