Antireflection Structures for Magneto-Optic Recording

Antireflective thin film structures(1) have been used advantageously in write – once(2)(3) and reversible phase change(4) materials design to provide increased sensitivity, better marking contrast and to amplify the optical effects of small laser-induced marking effects. The same structures may be used in magneto-optic recording to increase the shot-noise-limited figure of merit R½ΘK for Kerr readout. Previous reports have analyzed the effects of single quarter-wave overlayers(5) and more powerful approaches such as the encapsulated trilayer (quadrilayer)(6). This paper will present a comprehensive analysis of the various approaches to antireflection structures and their relative enhancement capabilities for shot noise limited magneto-optic readout.