Effect of metal surface morphology on nano-structured patterns induced by a femtosecond laser pulse and its experimental verification

The effect of material surface morphology on the periodic subwavelength of nano-structures induced by a femtosecond(fs) laser was investigated systematically from the initial surface roughness, the different scratches, the pre-formed ripples, and the "layer-carving" technology experiments. The results of the comparative experiments indicate that the initial surface conditions of the target surface have no obvious effects on the spatial structured periods(SSPs) and the ripple orientation of the periodic nano-structures induced by a fs laser, which agreed well with the foretold present surface two-plasmon resonance(STPR) model. Furthermore, different shapes of nanogrids with high regularity and uniformity were obtained by fs-laser fabrication.     

纳秒激光单脉冲烧蚀硅表面的超快成像研究

利用ICCD可以在纳秒时间尺度下成像的特点,以飞秒准连续激光产生的超短脉冲光为探测光,对纳秒激光单脉冲烧蚀硅靶表面的演化过程进行动态监测。在能量密度为50J／cm^2时,捕获了纳秒单脉冲激光烧蚀硅靶面过程中等离子体演化的时间分辨图像。图像表明,纳秒激光烧蚀硅靶产生的等离子体开始时密度大,膨胀速度快,当纳秒激光脉冲过后,等离子体不再产生,并且其膨胀速度不再增加,直至完全消失。