YbF3和YF3薄膜在0.4~14 μm超宽光谱内光学常数反演

为了获得红外低折射率材料的光学常数，采用电子束热蒸发技术在多光谱硫化锌基底上以不同的基底温度分别制备了单层氟化钇(YF₃)和氟化镱(YbF₃)薄膜。通过分光光度计和傅里叶变换红外光谱仪分别测试其在可见至远红外波段的透射率光谱曲线，使用包络法和色散模型拟合相结合的方法对其在可见至红外波段的光学常数进行了反演，得到了其在0.4~14 μm波段内的折射率与消光系数。采用椭偏测试结果验证了YF₃和YbF₃薄膜在0.4~1.6 μm波段内的光学常数正确性；将拟合得到的光学常数代入TFCalc 膜系设计软件，计算得到的单层薄膜的透射率光谱曲线与实测的光谱曲线吻合较好。实验结果表明，该方法获得的在超宽光谱0.4~14 μm范围内的光学常数准确、可靠。

Inverting optical constants of YbF3 and YF3 thin films in the ultra-wide spectrum from 0.4 to 14 μm

In order to obtain the optical constants of infrared low refractive index materials, single-layer yttrium fluoride (YF₃) and ytterbium fluoride (YbF₃) thin films were prepared on multispectral zinc sulfide substrates by electron beam thermal evaporation technique at different substrate temperatures. Spectrophotometer and Fourier transform infrared spectrometer were used to test the transmittance spectra of the optical parameters from visible to far-infrared bands, and the refractive index and extinction coefficient in the band of 0.4-14 μm were obtained by using the combination of envelope method and dispersion model fitting. The accuracy of the optical constants of YF₃ and YbF₃ films in the band of 0.4-1.6 μm was verified by the ellipsometry test results. The obtained optical constants were substituted into the TFCalc film design software, and the calculated transmittance spectrum curve of the monolayer film was in good agreement with the measured spectrum curve. The experimental results show that the optical constants obtained by this method are accurate and reliable in the ultra-wide spectral range of 0.4-14 μm.