飞秒激光在6H SiC晶体表面制备纳米微结构

激光诱导周期性纳米微结构在多种材料包括电介质、半导体、金属和聚合物中观察到。研究了800 nm和400 nm飞秒激光垂直聚焦于6H SiC晶体表面制备纳米微结构。实验观察到800 nm和400 nm线偏光照射样品表面分别得到周期为150 nm和80 nm的干涉条纹, 800 nm圆偏振激光单独照射样品表面得到粒径约100 nm的纳米颗粒。偏振相互垂直的800 nm和400 nm激光同时照射晶体得到粒径约100 nm的纳米颗粒阵列, 该纳米阵列的方向随400 nm激光强度增加而向400 nm偏振方向偏转。利

Laser-induced periodic nanostructures have been observed in several kinds of material including dielectric, semiconductor, metal and polymer. Fabrication of nanostructures on 6H SiC crystal illuminated by 800 nm and 400 nm femtosecond laser is studied. Interference ripples with period of 150 nm and 80 nm are produced by linearly polarized 800 nm and 400 nm femtosecond pulses, respectively. Spherical nanoparticles with diameter about 100 nm are formed after irradiation with circularly polarized 800 nm femtosecond pulses. Alignment of nanoparticles about 100 nm is obtained after simultaneous irradiation with 400 nm and 800 nm linearly polarized femtosecond laser pulses. The direction of the alignment changes to the polarization direction of 400 nm incident laser pulses, along with the increase of its pulses energy. With the help of the second harmonic generation, the formation mechanisms of these nanostructures are discussed.