采用化学腐蚀辅助皮秒激光成丝技术获得蓝宝石亚微米级精细切面的研究

Submicron Fine Cutting-Surface of Sapphire Obtained by Chemical Corrosion Assisted Picosecond Laser Filamentation Technology

以波长为1064nm的超短脉冲激光(脉宽为10ps)作为成丝激发源,引导自聚焦效应在蓝宝石内部产生了突破瑞利长度限制的成丝线迹。利用成丝区因相变而造成的与材料其他区域物相的不同,辅以化学腐蚀的方法,获得了切面粗糙度为800nm的蓝宝石切割件,该技术可实现自由路径切割。分析了皮秒激光的成丝特征和技术实现的工艺参数,确定了皮秒激光在蓝宝石内的自聚焦阈值功率为2.78×106 W,探究了激光峰值功率、聚焦位置及辐照点脉冲数对皮秒激光在蓝宝石内部成丝起始位置和切割质量的影响,获得了实现蓝宝石高精度切割的工艺参数。

The ultra-short pule laser with the wavelength of 1064 nm and the pulse width of 10 ps is used as filamentation excitation source to induce the self-focusing effect inside sapphire creating a long filamentation trace,and the length of the filamentation trace breaks through the limitation of Rayleigh length.On the basis of different phases between filamentation region and the rest of the sapphire,we obtain fine cutting-surface of sapphire with roughness of 800 nm with the help of chemical corrosion.Arbitrary cutting paths can be achieved by this technique.The filamentation characteristics of picosecond laser and the processing parameters for the presented technique are studied.The laser power threshold of self-focusing effect is determined to be 2.78×10^6 W.The effects of picosecond laser peak power,focusing position and the number of pulses on the initial position of filamentation and cutting quality are investigated.The processing parameters for realizing high precision cutting of sapphire are obtained.