Patent ID: 8345516

Claim:
A magneto-optical switching device for switching magnetization in a medium, comprising: a base substrate comprising a heat sink layer; a magnetizable medium stacked on the heat sink layer, the magnetizable medium comprising: a magnetizable domain layer consisting essentially of a metallic rare earth—transition metal alloy, and a capping layer; and an electromagnetic radiation system configured to produce an electromagnetic radiation beam having right or left handed circular or elliptical polarization of a selected angular momentum, the electromagnetic radiation system further being configured to produce a magnetized domain of a desired polarity on the magnetizable domain layer by the steps of: targeting the electromagnetic radiation beam at the magnetizable domain layer; and transferring the selected angular momentum to a magnetic spin system of the magnetizable domain, the transferring consisting essentially of irradiating the magnetizable domain through the capping layer, the transferring selectively orienting magnetization of a targeted part of the magnetizable domain layer in one or an opposite direction by an effective magnetic field depending on said right or left handed circular or elliptical polarization of the electromagnetic radiation beam.