Papers by Keyword: Interference Fringe

Abstract: In this study, we proposed a moved-view analysis, a method for obtaining the Soret coefficient S_T by analyzing the interference fringe change during field-of-view movement in the steady state. This analysis was designed to solve the problem that the sign of the concentration gradient could also be reversed if the plot of the concentration distribution was only slightly shifted owing to the narrow field of view. The data obtained from the experiment conducted to measure S_T at the International Space Station were analyzed using moved-view analysis. For the moved-view analysis, the linearity of the concentration distribution induced by the Soret effect is larger than that for the method without field-of-view movement, and a more reliable S_T can be obtained. The analysis error that sometimes occurred when the laser wavelength switched led to the underestimation of the phase change Δϕ, resulting in generating the data with low linearity. This unreliable data should be removed.

Abstract: Phase-shifting digital holography can be used for displacement measurement instead of strain gauge. Our research group is developing the measurement equipment for phase-shifting digital holography. Generally, in the measurement equipment, piezo stages are used as phaseshifting devices. But the piezo stage is expensive. Cheaper and smaller phase-shifting device is required in order to put the measurement equipment into practical use. In this paper, we, therefore, propose a phase-shifting device using the deflection of a cantilever and we verify whether this phase-shifting device can be used
for digital holography.