Upon excitation with extreme ultraviolet (EUV) radiation, optical windows ${{\rm CaF}_2}$ and sapphire emit strong photoluminescence (PL) in the ultraviolet region 200–400 nm. The spectral profiles of the windows observed in the PL spectra appear strongly dependent on their temperature. We suggest the use of PL spectra of ${{\rm CaF}_2}$ and sapphire excited with EUV light to indicate the temperature for EUV applications such as nano-photolithography technology in manufacturing semiconductor devices; potentially, the method is applicable to a wide range of radiation including the vacuum-ultraviolet (VUV) and EUV regions and in all fields.

中文翻译：

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极端紫外线激发的光学窗的光致发光

在用极紫外线（EUV）辐射激发后，光学窗口$ {{\ rm CaF} _2} $和蓝宝石在200-400 nm的紫外线区域发出强光致发光（PL）。在PL光谱中观察到的窗口的光谱轮廓似乎强烈取决于其温度。我们建议使用$ {{\ rm CaF} _2} $的PL光谱和EUV光激发的蓝宝石来指示EUV应用的温度，例如制造半导体器件中的纳米光刻技术；该方法潜在地适用于广泛的辐射范围，包括真空紫外线（VUV）和EUV区域以及所有领域。