大功率半导体激光加工光致等离子体折射效应  

Refraction effect of light-induced plasma during high-power diode laser processing

作　　者：潘吉兴 唐霞辉[1] 盛利民[1] 钟理京 许成文[1] 

机构地区：[1]华中科技大学光学与电子信息学院,武汉430000

出　　处：《激光技术》2015年第4期557-561,共5页Laser Technology

摘　　要：为了研究大功率半导体激光加工过程中,光致等离子体对激光光束显著的屏蔽作用,以波长为976nm、光斑尺寸为0.5mm×1mm、最大功率为4k W的半导体激光加工系统为实验基础,采用了与实际相符的光致等离子体电子密度数学模型和几何光学ABCD矩阵算法,从吸收和折射两方面对光致等离子体的屏蔽作用进行了理论分析和实验研究,得到了在光致等离子体电子密度ne≤1.0×1018/cm3的条件下,光致等离子体的折射效应才是引起半导体激光光束屏蔽的主要原因这一结果。结果表明,光致等离子体改变了聚焦光束的形态,使其焦点下移、光斑变大、能量密度变小,其效果类似于一个非线性梯度折射率的负透镜。In order to solve the significant shielding effect of light-induced plasma on laser during high-power diode laser processing,with the help of the mathematical model of electron density of light-induced plasma and ABCD matrix algorithm,the shielding effect of light-induced plasma was studied from the view of absorption and refraction based on a diode laser processing system with wavelength of 976 nm,spot size of 0. 5mm × 1mm and the maximum power of 4k W. The results showed that laser beam shielding effect is mainly due to refraction effect of light-induced plasma under the condition of electron density ne≤1. 0 × 10^18/ cm^3. Laser beam shielding effect changes laser beam shape,i. e.,making the laser focus down-shift,enlarging the spot and making the laser energy density smaller. The effect of induced-laser plasma is similar to a negative lens with non-linear gradient refractive index.

关 键 词：几何光学 折射效应 ABCD矩阵 光致等离子体 

分 类 号：O472.3[理学—半导体物理]