- Simplified analytic expressions are derived for the optical propagation matrix of magnetic anisotropic Kerr media using the Lagrange-Sylvester interpolation polynomial. This expression is used to investigate magnetic Kerr films in Fabry-Pérot configurations, magneto- optic recording quadrilayers and alternating periodic stacks. It is found that the magneto- optic reflection coefficients are enhanced by a few orders of magnitude due to multiple reflections. Bragg-type reflection peaks from periodic structure appear solely due to the gyrotropy and it is shown that omnidirectional reflection is possible under certain conditions. This analytic approach is faster than using direct numerical calculation.