Characterization of magneto-optical and phase-change media and systems for optical data storage

Abstract

This dissertation contains studies on several aspects of the media and system in the optical data storage. The main subjects that have been examined are magneto-optical (MO) media, phase-change (PC) media and the optical system used for recording and readout. In the studies of MO media, we examined the optical characteristics of magnetic garnets fabricated by sol-gel method and looked at how multilayer design can enhance MO effect. In the investigation of PC media, we developed a new technique to estimate thermal coefficients of erasable PC media, which allowed us to model the thermal profile during the writing and erasing process. In the investigation of the system, we designed and fabricated a variable leaky polarizing beamsplitter used in a dynamic tester for testing different optical disks throughout the wavelength range of 440nm-690nm. We also analyzed the application of partial response equalization and maximum likelihood sequence estimation in MO readout for high density recording.