飞秒激光在蓝宝石晶体表面加工微细结构的实验研究

由于蓝宝石晶体具有很高的硬度和耐磨蚀性,很难进行机械和化学腐蚀加工。笔者利用波长780 nm、频率1 kHz和脉冲宽度164 fs的飞秒脉冲激光在蓝宝石晶体表面进行了微细结构加工的实验研究。采用飞秒激光静态照射蓝宝石晶体表面,通过飞秒激光烧蚀孔的直径和脉冲能量的关系,计算了飞秒激光烧蚀蓝宝石晶体的两种烧蚀状态下的烧蚀阈值和有效烧蚀半径。通过直线扫描实验,在不同实验条件下在蓝宝石晶体表面加工微槽,获得微槽的宽度和深度与飞秒激光主要参数之间的关系。研究结果表明,微槽的加工表面可通过增加扫描次数而得到明显的提高,且扫描次数的增加对微槽的宽度和深度基本无影响。利用聚焦的飞秒激光束沿着轨迹扫描,在蓝宝石晶体表面加工出比较清洁的微小结构,可以为实现微结构的精密加工提供指导。

Experimental study on femtosecond laser micromachining of microstructures on sapphire

Aimed at addressing more difficult mechanical and chemical corrosion processing of sapphire crystal marked by high hardness and abrasion resistance,this paper introduces an experimental study on the fine structure processing of sapphire crystal surface using femtosecond laser pulses with a wavelength of 780 nm,frequency of 1 kHz,and pulse width of 164 fs.The study involves the calculation of ablation threshold and effective ablation radius due to ablation of sapphire crystal by femtosecond laser used two ablation states through static irradiation of sapphire crystal surface using femtosecond laser and the relation between pulse energy and diameter in holes produced by femtosecond laser.The paper describes the way the relation between the width and depth of the groove and key parameters of femtosecond laser is obtained by fabricating microgrooves under different experimental conditions,based on line-scanning experiment.Results reveal that the remarkable improvement in the surface quality of the fabricated microgrooves could be achieved by increasing the number of laser scans,thus leaving virtually no effect on the width and depth of the microgroove.The production of the cleaner tiny structures in the sapphire crystal surface by scanning along the track using focused femtosecond laser beam provides guidance for the precision machining of micro-structures.