Hlubina P, Ciprian D, Lunácek J, Lesnák M
Opt Express. 2006 Aug 21;14(17):7678-85. doi: 10.1364/oe.14.007678.
We present a white-light spectral interferometric technique for measuring the absolute spectral optical path difference (OPD) between the beams in a slightly dispersive Michelson interferometer with a thin-film structure as a mirror. We record two spectral interferograms to obtain the spectral interference signal and retrieve from it the spectral phase, which includes the effect of a cube beam splitter and the phase change on reflection from the thin-film structure. Knowing the effective thickness and dispersion of the beam splitter made of BK7 optical glass, we use a simple procedure to determine both the absolute spectral phase difference and OPD. The spectral OPD is measured for a uniform SiO(2) thin film on a silicon wafer and is fitted to the theoretical spectral OPD to obtain the thin-film thickness. The theoretical spectral OPD is determined provided that the optical constants of the thin-film structure are known. We measure also the nonlinear-like spectral phase and fit it to the theoretical values in order to obtain the thin-film thickness.
我们提出了一种白光光谱干涉测量技术，用于测量以薄膜结构作为反射镜的轻微色散迈克尔逊干涉仪中光束之间的绝对光谱光程差（OPD）。我们记录两个光谱干涉图以获得光谱干涉信号，并从中检索光谱相位，该相位包括立方分束器的影响以及薄膜结构反射时的相位变化。已知由BK7光学玻璃制成的分束器的有效厚度和色散，我们使用一个简单的程序来确定绝对光谱相位差和光程差。对硅片上的均匀SiO₂薄膜测量光谱光程差，并将其拟合到理论光谱光程差以获得薄膜厚度。假设薄膜结构的光学常数已知，则可确定理论光谱光程差。我们还测量了类似非线性的光谱相位，并将其拟合到理论值以获得薄膜厚度。
