激光微加工中,被加工材质与空气的折射率不同会产生像差,影响加工效果.基于激光微加工机理,运用波前像差函数推导出像差表达式,得到光学系统参数、加工深度与像差的关系曲线.采用泽尔尼克循环多项式对像差进行补偿,获得补偿后的系统点扩散函数.以双光子飞秒脉冲激光在光致变色材料上进行点加工为例,对该补偿函数进行数值模拟.仿真结果表明建立的补偿模型能有效校正像差.初级像差补偿后,加工点荧光信号强度衰减现象得到显著改善,加工深度可接近600 μm;二级像差补偿后,信号强度基本不随加工深度的改变而改变.提出使用开普勒望远镜系统进行像差补偿的方法并进行试验,对补偿效果进行深入分析.理论与试验结果为激光微加工过程中减小像差,改善加工效果提供了充分的依据.

Laser micromachining is processed materials and refractive index of air will produce different aberrations affect processing results. Based on the mechanism of laser micro-machining,the use of wavefront aberration function derived expressions,giving an optical system parameters versus depth of processing and aberrations. A systematic point of Zernike polynomials cycle to compensate for aberrations,get compensated spread function. In two-photon femtosecond pulse laser in photochromic material point-processing,for example,the compensation function for numerical simulation. Simulation results show that the compensation model can effectively correct aberrations. After the primary aberration compensation processing point fluorescence signal strength attenuation phenomenon has been significantly improved,the processing depth accessible 600 μm; after two aberration compensation,signal strength with almost no change in the depth of processing changes. Kepler proposed system using aberration compensation method and tested,in-depth analysis on the compensation effect. Theoretical and experimental results for the laser micromachining process,reduce aberration and improve the processing results provide a sufficient basis.