飞秒激光诱导硒化锌晶体表面自组织生长纳米结构

Femtosecond pulse laser-induced self-organized nanostructures on surface of ZnSe crystal

以250 kHz高重复频率钛宝石飞秒激光聚焦到硒化锌晶体表面,利用扫描电子显微镜观测飞秒激光辐照后晶体的表面结构。发现线偏振激光辐照的区域形成了自组织周期性纳米结构,其周期为160 nm左右,并且可以通过改变激光的偏振方向调节纳米光栅结构的取向;当晶体相对于激光光束以10μm/s速度移动,经激光扫描后,在晶体表面形成了长程类布拉格光栅。当飞秒激光光束为圆偏振光时,辐照区域形成均匀的纳米颗粒。

Self-organized nanostructures were observed on the surface of ZnSe crystal after irradiation by a focused beam of a femtosecond Ti： sapphire laser with a repetition rate of 250 kHz. For a linearly polarized femtosecond laser, a periodic nanograting structure on the ablation crater surface was promoted. The period of these self-organization structures is about 160 nm. The grating orientation can be adjusted by changing the laser polarization direction. A long range Bragg-like grating formed by moving the sample at the speed of 10 μm/s in the horizontal plane. For a circularly polarized laser beam, uniform spherical nanoparticles formed.