減衰全反射 (ATR) 赤外分光における金属面の重ね合せの効果

Abstract

A surface casted thinly polymer (PVAC for experiment) on Au layer deposited on a PET film was overlaid to a reflection surface of a germanium prism at an incident angle of 22°. Absorbance of reflection spectra by P polarized radiatioa from these configuration was 2.5 times more than one of reflection-absorption spectra at an incident angle of 80°. Gains of absorbance by overlaying metal surfaces to the reflection surface of the germanium prism decreased at large incident angles, when coarse surfaces of metals were applied. It was due to an air layer between the metal surface and the reflection surface of the germanium prism, whose thickness exceed a penetration depth of the electromagnetic field from the refrection surface. Spectra of the PVAC film on the reflection surface of the prism by the S poralized radiation suggested how thick the air layer was in comparison with the penetration depth.