不同类型修复坑形貌对光传输的影响北大核心CSCD

建立了不同类型熔石英元件损伤修复坑形貌的三维模型,利用标量衍射理论并结合快速傅里叶变换算法研究了在351nm激光辐照下修复坑形貌对光传输的影响规律。研究表明,无论是锥形、抛物形或是高斯形修复坑形貌,均会产生离轴位置的环形光场调制增强区,其环形调制极大值均主要受修复坑深度影响,随着修复坑深度的增大而增大,而其分布位置随着修复坑深度的增加逐渐靠近修复元件后表面,随着修复坑底面半径的增大而远离修复元件后表面;同时,当修复坑深度与底面半径一定时,三类修复坑形貌中以抛物形修复坑形貌最为理想。

Effects of different kinds of mitigated pits on transport of laser beam

According to the different kinds of morphology features, 3D grid models of mitigated pits were built, and effects of different kinds of mitigated pits models on transport of laser beam (351 nm) was studied by using scalar diffraction theory and Fast Fourier Transform (FFT) methods. The results indicate that the off-axis downstream intensification of different kinds of mitigated pits, including conic, parabolic and Gaussian, pits, mainly relies on the depth of the mitigated pit. For the off-axis intensification, the maximum intensity increases with deepening depth, and the location of the maximum intensity approaches the output surface of optics with increasing pit depth, and is far away from the output surface of optics with the increasing diameter of mitigated pits. In addition, when the depth and diameter of different kinds of mitigation pits are equal, the parabolic mitigated pits can be the best choice for mitigated morphology. The results of this research indicate that the downstream intensification, which is induced by the mitigated damage pits, can be suppressed by controlling the morphology features of mitigated pits.