中文摘要：

固体的光学性质是凝聚态物理学中的一类重要问题，它可以用一系列的光学常数进行描写．在实验上，最常用的方法是，测量材料在一个尽可能宽的频率范围内的正入射反射率，然后通过Kramers-Kronig（KK）变换的方法来得到光学常数．文章介绍了傅里叶变换红外反射光谱的原理、仪器组成和一种原位蒸发镀膜技术．这样的方法可以很好地测量包括小尺寸和不规则样品在内的材料从数个毫电子伏至数个电子伏范围内的反射率，因而在研究固体的各种不同的单粒子激发（或集体激发）中起重要的作用．

英文摘要：

The optical properties of solids is of great importance in condensed matter physics, and can be characterized by a set of optical constants. The most common experimental practice is to measure the sample＇s reflectivity at normal incidence over a broad frequency range, and then obtain the optical constants via the Kramers-Kronig transformation. In this article we introduce the basics of Fourier transform infrared reflectivity spectroscopy, the experimental setup, and an in-situ overcoating technique which can measure the reflectivity of samples, including those of small size or irregular shape, from several meV to several eV. This method should thus play an important role in the study of various single particle excitations or collective excitations in solids.