Laser-Beam Recording on a Magnetic Film

Abstract

A method of recording digital information on a thin magnetic film is described. The change of magnetization in the film is accomplished by a coincidence of a high-power optical beam from a laser and a magnetic field. Films having coercive force ratios Hc(25°C)/Hc(150°C) of at least 3 were used as the media. Information was recorded with a 1 W Argon-Ion laser beam controlled by an electrooptic switch to provide spots down to 3.5μ diam. Photographs and electrical readout of tracks of written bits are presented.