一种设计二元衍射元件的优化方法

AN EFFECTIVE METHOD FOR DESIGNING BINARY OPTICAL DIFFRACTIVE ELEMENTS

基于菲涅耳衍射原理和Gerchberg-Saxton的迭代算法,提出一种孔径分区设计二元衍射元件的优化方法.采用此方法设计的二元衍射元件产生的目标光强于输入激光的模式是不敏感的.具体设计与研制了用于CO_2激光表面(火卒)火处理的二元衍射元件,该衍射元件使CO_2激光束变形成12mm×2mm的矩形光斑.试验结果表明,产生的目标光斑满足设计要求.

Based on the principle of Fresnel diffraction and Gerchberg-Saxton algorithm, an effective method for designing binary optical diffractive elements (BODE) is presented. The objective light distribution, generated by a BODE designed by this method, is not sensitive to laser mode. A BODE, used in quenching treatment of CO2 laser, was designed and fabricated by photolithography and ion etching techniques. The element could transform a CO2 laser beam into rectangle beam shape with dimensions 12 mm×2 mm. The experimental results are satisfactory for the quenching treatment .