It consists of two parallel polarizers, an electro-optical crystal and a birefringent crystal with radial symmetry.

该光瞳滤波器由两个平行偏光镜，一个电光晶体与一个径向对称双折射晶体组成。

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The vacuum itself is polarized, becoming strongly birefringent, like a calcite crystal.

真空本身被极化，变得具有很强的双折射性质，如同方解石一般。

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