Berreman D W
Bell Telephone Laboratories, Murray Hill,New Jersey 07971, USA.
Appl Opt. 1967 Sep 1;6(9):1519-21. doi: 10.1364/AO.6.001519.
Kramers-Kronig analysis of spectra of reflectance has usually been done only with radiation incident as nearly normal to the sample surface as possible. Any effects of obliquity have been assumed to be negligible. However, it is not much more difficult or time consuming to do Kramers-Kronig analysis of spectra taken with almost any angle of incidence, provided that polarized radiation is used to obtain the data. The method for such analysis for radiation incident at almost any angle is described in this paper. The method fails with pi polarized radiation if the angle of incidence lies between the two somewhat different Brewster angles at the high and low frequency ends of the spectrum. The rather small error in a typical analysis caused by neglecting a 15 degrees angle of incidence is illustrated.
通常，仅在辐射尽可能接近垂直入射到样品表面时才对反射光谱进行克拉默斯-克勒尼希分析。倾斜的任何影响都被认为可以忽略不计。然而，只要使用偏振辐射来获取数据，对几乎任何入射角下拍摄的光谱进行克拉默斯-克勒尼希分析并不困难多少，也不会花费更多时间。本文描述了针对几乎任何入射角的辐射进行这种分析的方法。如果入射角介于光谱高频端和低频端两个略有不同的布儒斯特角之间，该方法对π偏振辐射会失效。文中说明了在典型分析中忽略15度入射角所导致的相当小的误差。
