Sellmeier色散公式和扩展的Lorentz-Lorenz色散函数表达式是两种常用的描述不同温度条件下物质折射率与入射光波长的变化关系式。为了探讨两 者在计算光在水中色散问题的区别,运用两种不同的计算模型,在400～1100 nm波长范围内,4种不同温度下,分别模拟了蒸馏水中折射率、 群折射率、群速度色散及三阶色散随光波长的变化曲线,同时分析了由此两种不同理论计算模型给出的主要计算结果之间的差异。 结果显示,尽管由两种关系式计算得出的蒸馏水的折射率和群折射率基本相同,但群速度色散和三阶色散的结果却存在很大的差别。

Sellmeier dispersion formula and Lorentz-Lorenz function are two common formulas that describe the relationship between the refractive index of materials and the wavelength of the incoming light wave at different temperatures. To examine the differences between the calculation results based on these two formulas, two theoretical models are used to simulate the refractive index, group index, group velocity dispersion (GVD), and the third order dispersion (TOD) of distilled water within the wavelength range of 400～1100 nm at four different temperatures respectively. The differences between the calculated results are analyzed. It is shown that the difference between refractive index and group index is rather small, but the differences in GVD and TOD can be relatively large.