| 摘要 |
PURPOSE:To improve the light absorption measurement precision of a measuring instrument by irradiating a thin film expanded on a liquid surface with exciting light from the liquid side and reflecting it totally, and passing probe light nearby the irradiated position and detecting the quantity of polarization of the probe light. CONSTITUTION:The thin film 4 is expanded on the liquid surface 3 in a liquid tank 1. Further, the exciting light 11 is emitted by an exciting light source 10 and sent intermittently through a chopper 12, and made incident on the thin film 4 from the liquid side and reflected totally. At this time, the irradiated part of the thin film 4 varies in refractive index. Further, the probe light 6 from a probe light source 5 is passed in parallel to the liquid surface right under the liquid surface. The probe light 6 is polarized by the refractive index variation part of the thin film 4 and reaches a detector 7. The detector 7 finds the light absorption characteristics of the thin film 4 from the quantity of polari zation of the probe light. Thus, the exciting light is made incident from the liquid side, so the measurement precision of the measuring instrument for the light absorption characteristics of the thin film is improved. |
