Angular Dispersion-type Nonscanning Fabry-Perot Interferometer Applied to Ethanol-water Mixture

Abstract

The angular dispersion-type non-scanning Fabry-Perot was applied to an ethanol-water mixture in order to investigate its acoustic properties such as the sound velocity and the absorption coefficient. The scattered light from the mixture was analyzed by using the charge-coupled-device area detector, which made the measurement time much shorter than that obtained by using the conventional scanning tandem multi-pass Fabry-Perot interferometer. The sound velocity showed a deviation from ultrasonic sound velocities at low temperatures accompanied by the increase in the absorption coefficient, indicating acoustic dispersion due to the coupling between the acoustic waves and some relaxation process. Based on a simplified viscoelastic theory, the temperature dependence of the relaxation time was obtained. The addition of water molecules to ethanol reduced the relaxation time, consistent with dielectric measurements. The present study showed that the angular dispersiontype Fabry-Perot interferometer combined with an area detector could be a very powerful tool in the real-time monitoring of the acoustic properties of condensed matter.

Pressure Dependence of Acoustic Properties of Liquid Ethanol by using High-pressure Brillouin Spectroscopy

“…[10] Moreover, an angular dispersion-type Fabry-Perot interferometer combined with an area detector can be used to monitor real-time changes in the acoustic properties. [11][12][13] Excellent review articles on Brillouin spectroscopy can be referred to for more details. [14][15][16][17] One of the main areas to which Brillouin spectroscopy has been applied is the physics of phase transitions.…”

Micro-Brillouin Spectroscopy Applied to the Glass Transition of Anti-inflammatory Egonol

“…Second, it is difficult to investigate small samples of which the size is the order of µm. The first problem can be overcome by using the so-called angular dispersiontype Fabry-Perot interferometer combined by an area detector [4,5]. The second difficulty can be solved by adopting an optical microscope in the T-FPI [6].…”