Effect of multilayer structure and laser pulse width on the reversible cycling of phase change optical storage media

The static cycling behavior of chalcogenide phase change optical recording media was investigated. Thin-film multilayer structure and laser pulse conditions were both varied to determine optimum conditions for good cycling behavior. For all structures, cyclability was always best for short pulses. An aluminum overcoat layer was found to substantially increase the performance. The effect of the temperature excursion experienced during writing on cycling was determined. At the shortest pulses it was demonstrated that the thermal excursions did not depend upon the presence of an aluminum overcoat, suggesting that mechanical strength was important for enhancing cyclability. For longer pulses the aluminum changed the thermal characteristics of the stack. These differences between various samples are compared to try to elucidate modes of failure in optical data storage structures.