POLARIMETRIC CHARACTERIZATION OF THIN PLATES OF FERROFLUIDS - APPLICATION TO ACTIVE IMAGERY

We have measured the spatial distribution of birefringence DELTAn for two ferrofluids (Fe2C0O4 and gammaFe2O3), subjected to a continuous ma gnetic field perpendicular to the propagation direction of a laser bea m. These measurements have been made for small thickness of ferrofluid s, using an argon laser (514 nm) and a CCD camera. The samples show a linear dependence on ferrofluid concentration and thickness; the resul ts show the possibility of using ferrofluid thin plates in active imag ery.