Khashan M A, Nassif A Y
Department of Physics, Faculty of Science, Ain Shams University, Cairo, Egypt.
Appl Opt. 1997 Sep 20;36(27):6843-51. doi: 10.1364/ao.36.006843.
The band spacing of the fringes of equal chromatic order of a thin Fabry-Perot interferometer is compared when this interferometer contains air, a solid, or a liquid. This comparison enables the dispersion of the group velocity of light in these media to be known accurately to 2.4 parts in one thousand. The Sellmeier dispersion function is used to deduce the refractive indices with the same degree of accuracy. The order-transformation method is used to find the exact order values from the roughly known optical thickness. The exact order values for air and the sample are used to find the refractive index accurately to approximately 3 x 10(-5). A least-squares fitting of the accurate experimental data to the Sellmeier dispersion function enables the coefficients of the latter to be more precisely defined for solids such as glass and mica and for liquids such as glycerin and distilled water. The atomic parameters such as the density of states and the absorption wavelengths in the ultraviolet region of the spectrum for the given samples are deduced from the more precisely found Sellmeier coefficients.
比较了薄法布里 - 珀罗干涉仪在包含空气、固体或液体时等色序条纹的条纹间距。这种比较能够将光在这些介质中的群速度色散精确到千分之2.4。利用塞耳迈耶色散函数以相同的精度推导出折射率。采用阶次变换法从大致已知的光学厚度求出精确的阶次值。利用空气和样品的精确阶次值将折射率精确到约3×10⁻⁵。通过将精确的实验数据与塞耳迈耶色散函数进行最小二乘拟合，能够更精确地确定玻璃和云母等固体以及甘油和蒸馏水等液体的塞耳迈耶色散函数系数。从更精确得到的塞耳迈耶系数推导出给定样品在光谱紫外区域的诸如态密度和吸收波长等原子参数。
