Kazasidis Orestis S, Wittrock Ulrich
Opt Express. 2014 Dec 15;22(25):30683-96. doi: 10.1364/OE.22.030683.
We report interferometric measurements of the temperature coefficient of the refractive index (dn/dT) and the coefficient of thermal expansion (α) of a praseodymium-doped yttrium lithium fluoride (Pr:YLF) crystal and of a fused silica reference sample. Our phase-resolved interferometric method yields a large number of data points and thus allows a precise measurement and a good error estimation. Furthermore, both dn/dT and α are obtained simultaneously from a single measurement which reduces errors that can occur in separate measurements. Over the temperature range from 20 °C to 80 °C, the value of dn/dT of Pr:YLF decreases from −5.2 × 10(−6)/K to −6.2 × 10(−6)/K for the ordinary refractive index and from −7.6 × 10(−6)/K to −8.6 × 10(−6)/K for the extraordinary refractive index. The coefficient of thermal expansion for the a-axis of Pr:YLF increases from 16.4 × 10(−6)/K to 17.8 × 10(−6)/K over the same temperature range.
我们报告了掺镨氟化钇锂（Pr:YLF）晶体和熔融石英参考样品的折射率温度系数（dn/dT）以及热膨胀系数（α）的干涉测量结果。我们的相位分辨干涉测量方法产生了大量数据点，从而能够进行精确测量并得到良好的误差估计。此外，dn/dT和α都可从单次测量中同时获得，这减少了单独测量中可能出现的误差。在20℃至80℃的温度范围内，Pr:YLF的寻常折射率的dn/dT值从−5.2×10(−6)/K降至−6.2×10(−6)/K，非寻常折射率的dn/dT值从−7.6×10(−6)/K降至−8.6×10(−6)/K。在相同温度范围内，Pr:YLF的a轴热膨胀系数从16.4×10(−6)/K增加到17.8×10(−6)/K。
