飞秒激光与金刚石相互作用机理仿真和实验研究

Simulation and Experimental Research of Interaction Mechanism Between Femtosecond Laser and Diamond

为了探究飞秒激光与金刚石的相互作用机理,本研究针对化学气相沉积法制备的单晶金刚石,基于COMSOLMultiphysic仿真软件,采用能量守恒公式和傅里叶热传导定理公式,建立基于温度场的飞秒激光加工单晶金刚石仿真模型,研究激光平均功率、激光扫描速度、激光重复频率和激光脉冲有效个数四个影响因素对金刚石流道宽度和深度形貌的影响规律。并搭建了飞秒激光加工实验平台,测试结果与仿真结果进行对比。结果表明:飞秒激光多脉冲加工金刚石,作用过程分三个阶段:弱烧蚀石墨化阶段、强烧蚀气化阶段以及稳定阶段。获得飞秒激光系统的最佳加工参数:平均功率(P_(avg))为5~10 W,重复频率(f)为50~200 kHz,正焦,光斑重叠率为63%~85%,脉宽最小。

In order to explore the interaction mechanism between femtosecond laser and diamond,this study,focusing on single crystal diamond prepared by chemical vapor deposition method,based on COMSOL Multiphysic simulation software,the energy conservation formula and Fourier heat conduction theorem formula were used to establish a simulation model of femtosecond laser processing single crystal diamond based on temperature field.The influence law of four influencing factors,including laser average power,laser scanning speed,laser repetition rate,and effective number of laser pulses,on the width and depth morphology of diamond flow channels was studied.And a femtosecond laser processing experimental platform was built,and the test results were compared with the simulation results.The results show that the femtosecond laser multi-pulse processing of diamond was divided into three stages:weak ablation graphitization stage,strong ablation gasification stage and stable stage.The optimal processing parameters for femtosecond laser system was obtained:average power(Pavg)was 5-10 W,repetition rate(f)was 50-200 kHz,positive focus,spot overlap rate was 63%-85%,and minimum pulse width.