提高二元光学器件衍射效率的准连续编码策略

A quasi continuous coding method to enhance DOE's diffraction effenciency

基于标量衍射理论，二元光学器件的衍射效率，微结构误差对衍射效率的影响，提出了一种准连续编码方法，并给出了加工非２ｎ台阶所需掩模板的具体形式。在一定的加工条件和工艺水平下，采用这种编码方法，可以不增加加工成本和工序，仅通过新颖的掩模板设计方法充分利用现有加工条件和设备，使二元光学器件的衍射效率得到很大程度的提高。从而不仅能使一般混合系统的效率得到提高，更能充分发挥混合光学系统的成像能力。此编码方法的采用有利于推进二元光学器件的实用化。

Basedd on the scalar diffraction theory, the feature of diffraction efficiency of binary optical elements(BOE) and the influence of the relief structure error on it, the quasi continuous mask coding(QCMC) method is presented, and its concrete mask pattens are also given used for fabricating non 2 n step microstructure. Just by taking full advantage of the available processing facilities without any additional cost or working procedure, BOE with significantly enhanced diffraction efficiency will be fabricated by using QCMC. Using this method can not only improve the performance of any hybrid optical system, but also raise the image quality of the hybrid image system. This coding technique will exactly promote the application of binary optics.