COMPUTER EXPERIMENTS ON THE INFORMATION DEPTH AND THE FIGURE OF MERIT IN MAGNETOOPTICS

A numerical simulation procedure is used to answer some fundamental questions about magnetooptical phenomena. By investigating hypothetical thin buried layers of magnetic material in a non-magnetic environment of otherwise identical optical properties a suggestive law is derived for the information depth profile of Kerr effect measurements. Differences in phase between contributions from different depth often limit the range of the Kerr effect to a higher degree than absorption. In oxides the profile has usually an oscillating character, but conditions are derived under which these oscillations can be suppressed. The differing phase of sub-surface contributions connects these considerations with Kambersky's interpretation of the recently discovered magnetooptical gradient effect. Finally, the theoretical and practical possibilities are explored of enhancing the Kerr effect in ultra-thin films in which all the light is forced to react in a thin layer rather than in the depth of a thick material. In this connection a far-reaching generalization of Lissberger's limit for the Kerr amplitude in thin film mirror-based systems is discovered.