Abstract

The nucleation and growth of domains written into a rare earth-transition metal thin film by thermo-magnetic writing with an AlGaAs diode laser have been observed with a high speed magneto-optic camera having a 10 nsec exposure time.lt is observed that the domain is nucleated thermo-magnetically within 20 nsec after the leading edge of the write pulse. The domain grows in size until 50-150 nsec after the termination of the write pulse, then shrinks as the heated area cools and finally reaches an equilibrium size. For very short write pulses, no shrinking of the domain is observed after the termination of the write pulses. It is found that increased laser power or longer laser pulse duration increases the final domain size, but not in proportion to total energy applied. Over 10⁶ write/erase cycles on the same spot on the film have been found to produce no deterioration in magneto-optical performance and no change in nucleated domain size or its erasability.

© 1984 Optical Society of America