divergent light input 发散光输入
The astigmatism from a plane grating placed in the divergent light beam was used to compensate the astigmatism from an objective lens.
将平面光栅置于发散光中，利用平面光栅产生的像散来补偿物镜产生的像散。
The advantages are that defects light are not divergent and just transforming mask can fabricate different types of photonic lattice. The disadvantages are complexity of device, not easy to adjust.
此方法的优点是缺陷光是不发散的，只需变换掩膜就可以得到不同类型的光子晶格，缺点是装置复杂，不易调节。
The disadvantage of sheet-light is divergent and can not make more small defects, and can only use thin crystal in experiment.
缺点是经圆柱透镜形成的片光具有发散性，不能制作小数量级的缺陷，并且实验中只能使用薄晶体。
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