INSTRUMENT FOR MEASURING LIGHT ABSORPTION CHARACTERISTIC OF THIN FILM

摘要

PURPOSE:To improve the accuracy of measuring the light absorption characteristic of a measuring instrument by providing a thin film developed on a liquid surface and a specular surface thereunder, making incident excitation light thereon from the liquid side so as to make multiple reflections between the thin film and the specular surface and polarizing largely probe light in the reflection region thereof. CONSTITUTION:The thin film 4 is developed on the liquid surface 3 in a liquid tank 1 and the specular surface 13 is provided thereunder. The excitation light 11 is emitted from an excitation light source 10 and is intermitted by a chopper 12. Said light is fed and is irradiated from the light side to the thin film 4. The reflected light thereof is totally reflected by the surface 13. The probe light 6 is passed between the film 4 and the surface 13. Since the light 11 is multiple-reflected by the film 4 and the surface 13, the light 6 is polarized largely by passing through the polarizing region. The quantity of the polarized light is detected by a detector 7 and the light absorption characteristic of the thin film is measured. The measuring instrument is so constituted as to form the multiple-reflection region by irradiating the excitation light from the liquid side on the thin film and therefore the accuracy of measuring the light absorption characteristic of the measuring instrument is improved.