为了解决目前光学分束器件衍射效率低的问题,在传统的Gerchberg-Saxton(GS)算法基础上, 对初始相位和迭代算法中的振幅限制方式作改进.先利用二次相位来作为迭代算法的初始相位, 再在迭代过程中将输出平面分为信号区和噪音区两部分, 保持这两部分的相位不变, 信号区内振幅乘上一个随迭代次数不断变化的因子, 噪音区内振幅保持不变. 通过该方法设计9×9连续面形的分束器件, 并与传统GS算法设计的分束器进行了对比, 结果表明: GS算法设计得到的分束器相位存在严重的突变和不连续等问题, 而本文方法设计得到的分束器相位连续平滑, 可利用移动掩模技术加工. 最终制备出1×3和1×9分束器, 其实测的衍射效率分别为83.5%和89.4%, 均匀性误差分别为3.56%和15.23%.

Aiming at the low diffraction efficiency of optical beam splitting devices, based on the traditional Gerchberg-Saxton (GS) algorithm, the initial phase and the amplitude limitation method is improved. The secondary phase is used as the initial phase of the iterative algorithm, and then the output plane is divided into the signal area and the noise area. Keeping the phase of the two parts unchanged, the amplitude in the region is multiplied by a factor which varies with the number of iterations, and the amplitude in the noise region remains unchanged. A 9×9 continuous-face beam splitting device designed by the proposed method is compared with the beam splitter designed by the traditional GS algorithm. The results show that the phase of the beam splitter designed by GS algorithm has serious mutation and discontinuity. However, the beam splitter phase designed by the proposed method is continuously smooth and can be processed by the moving mask technique.The 1×3 and 1×9 beam splitters are prepared, the measured diffraction efficiency are 83.5% and 89.4%, the uniformity error are 3.56% and 15.23%, respectively.