Authors: F. Behroozi
Affilation: The University of Northern Iowa, United States
Pages: 166 - 169
Keywords: interferometer, laser, capillary waves, viscosity
A miniature laser interferometer consisting entirely of an optical fiber held in close proximity to a fluid surface is described. The total path difference in this interferometer is less than a millimeter. The interferometer may be used to measure, for example, the amplitude of submicron capillary waves with a resolution of about 10 nm. In one application the interfermeter is used to measure, noninvasively, the amplitude decay of capillary waves as a function of the distance from the wave generator. The amplitude decay data yields the viscosity of the fluid with unprecedented precision. As a test case, the viscosity of pure water as a funtion of temperature, measured by this system, is presented.