Interference Experiment of a Soap-Bubble Film by Optical Spectroscopy: Synchronous Measurements of Interference Spectra of the Light Reflected from and Transmitted through the Soap Bubble

Abstract

Recently, a rapid-scan multichannel CCD optical spectrometer has enabled us to measure the thickness of a soap film. In this research, we carried out a synchronous measurement of interference spectra of the light reflected from and transmitted through the soap bubble produced along the optical path to the spectrometer. The observed spectra showed fringe patterns whose phase was different by π between reflected and transmitted spectra, which was caused by the difference between fixed-end and free-end reflections. The precise time-dependent changes in the thickness of the soap-bubble film were obtained by simulation analysis of the interference spectra observed. The results suggest a useful teaching material suitable for the diffraction and interference experiment of light in science education.