A Miniature Laser Interferometer for Noninvasive Viscometry

Fred Behroozi
The University of Northern Iowa, US

Keywords: Interferometer, laser, capillary waves, viscosity

Abstract:
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[1] 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, will be presented. [1] F. Behroozi, B. Lambert, and B. Buhrow, Applied Physics Letters 78, 2399 (2001).

NSTI Nanotech 2003 Conference Technical Program Abstract