These holographic gratings are characterized by seamless patterns and a low defect density on a large area, due to a special fabrication technology.

这些全息光栅的特点是无缝模式和大面积低缺陷密度，由于特殊的制造技术。

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To avoid forming layer defect, rising pouring temperature are using improved coating and selecting low density styrofoam pattern are a great help.

提高金属液浇注温度及改良涂料，选用低密度泡沫塑料作模样材料对避免产生分层缺陷有帮助。

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