Simplified analytic expressions are derived for the optical propagation mat
rix of magnetic anisotropic Kerr media using the Lagrange-Sylvester interpo
lation polynomial. This expression is used to investigate magnetic Kerr fil
ms in Fabry-Perot configurations, magneto-optic recording quadrilayers and
alternating periodic stacks. It is found that the magneto-optic refection c
oefficients are enhanced by a few orders of magnitude due to multiple refle
ctions. Bragg-type reflection peaks from periodic structure appear solely d
ue to the gyrotropy and it is shown that omnidirectional reflection is poss
ible under certain conditions. This analytic approach is faster than using
direct numerical calculation.