MAGNETIC BIREFRINGENCE IN THIN FERROMAGNETIC FILMS

Intensity variations observed in light (λsimilar, equals0·95 μm) transmitted normally by thin magnetic films of Fe, Ni-Fe (81-19) and Co with uniaxial anisotropy when switched along their hard direction, are attributed directly to magnetic birefringence. The intensity changes are of the order of one part in 103. Theoretical considerations enable the form of the intensity variations to be predicted, and show that measurement of their magnitude for a particular optical configuration leads to the magnitude of the complex magneto-optic parameter.