Patent ID: 7265845
Filing Date: 2007-09-04
Classification: G01N

Abstract:
1. A magneto-optical indicator element comprising: a substrate; a thin film indicator structure comprising a plurality of thin-film layers disposed on a said substrate, at least one of said layers comprising magneto-optically (MO)-active material having predetermined magnetic properties including magnetic anisotropy, magnetization saturation value, coercive field value; and a magneto-optical effect value; said indicator structure including at least one of said layers having a thickness and/or refractive index modulated in a predetermined fashion; said indicator structure having at least one optical mode which is at least partially localized within and/or at at least one interface of said at least one MO-active layer; said at least one optical mode being at least partially localized in said one layer having modulated thickness and/or refractive index, further comprising a thin layer of metal having a thickness of no more than 15 nm and selected from the group, consisting of: Ag, Al, Au, Cu disposed contiguous to said layer of ferromagnetic material, wherein the optical mode comprises a surface plasmon mode and at least one magneto-optically-active layer provides a single surface that supports the surface plasmon mode, wherein said MO-active layer comprises ferromagnetic material, wherein said thin layer of metal has a constant thickness, and wherein said metal layer has a modulated thickness and is disposed adjacent to a thin layer of metal on a side opposite to the MO-active layer.