飞秒激光在6H-SiC表面诱导偏振依赖纳米结构特性研究

Study on the polarization dependentproperties of femtosecondlaser-induced nanostructures on 6H-SiC crystal surface

摘要:

激光诱导偏振依赖纳米结构是一种有效实现纳米图案化的技术,并且一直备受研究者的青睐。利用飞秒激光微加工技术,对6H-SiC晶体表面激光诱导偏振依赖纳米结构特性进行了研究。通过改变入射激光加工偏振态和延迟时间样品表面诱导产生了直径约为150 nm的球形纳米颗粒、椭圆形纳米颗粒和空间周期约为150 nm的高空间频率表面条纹结构。实验结果表明,入射激光偏振特性会直接影响诱导产生的微结构形貌,并且优先入射的飞秒激光对最终产生的表面微结构形貌有决定性作用。初步探讨了偏振依赖纳米结构形成的物理机制,表面等离激元(surface plasmon polariton,SPP) 在表面微纳米结构的产生过程中扮演着重要角色,研究结果对激光诱导表面周期结构(laser-induced periodic surface structures,LIPSS) 可控制备具有重要意义。

Abstract:

Polarization dependent of laser-induced nanostructures is an effective technique to realize nano-pattering and has been favored by researchers.The polarization-dependent characteristics of laser-induced nanostructures on 6H-SiC crystal surface are investigated by the method of femtosecond laser micromachining.The spherical nanoparticles with a diameter of about 150 nm,the elliptical nanoparticles and the periodic ripple structures with the period of 150 nm have been fabricated on sample surface by controlling the laser machining parameters of polarizations and time delays.The results show that the polarization properties of incident laser directly affect the induced microstructure morphologies,and the femtosecond laser with preferential incident plays a decisive role in the final surface micro-nano structures.The physical mechanism of polarization-dependent formation of laser-induced nanostructures is preliminarily discussed,the surface plasmon polariton (SPP) plays an important role in the generation of surface micro-nano structures,and the research results are of great significance for the controllable fabrication of laser-induced periodic surface structures (LIPSS).