Abstract

The frequency and temporal response of several magnetooptic thin films have been measured. The thin films, formed from combinations of rare earth-transition metal (RE-TM) alloys, were supplied by their commercial developers. The measurements consisted of writing at various laser carrier frequencies, duty cycles, and incident laser powers in the presence of a bias magnetic field. The resulting laser mark is read with a continuous low-power laser beam. The laser marking consists of a change in magnetization which produces a birefringence which is measured as a Kerr rotation of the linearly polarized read laser beam. The measurements obtained in this fashion have been spectrum analyzed to determine the transfer functions as a function of the write laser parameters. We found that the transfer functions vary anomalously with incident laser parameters. The anomalous behavior can be understood in terms of the heating cycle induced by the write laser. Experimental data and their analysis are presented.

© 1988 Optical Society of America