The wavelength converting material is mounted on the exit surface and directly or indirectly emits converted light into a medium that has a relatively low refractive index.

波长转换材料安装于出射表面上并且直接地或间接地将所转换的光发射到具有相对较低折射率的介质内。

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All-reflective optical systems, due to their material absorption and low refractive index, are used to create the most suitable devices in extreme ultraviolet lithography (EUVL).

由于材料的吸收和低折射率问题，极紫外光刻所采用的光学系统发展趋势是全反射型。

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