Abstract

Many attempts have been made to record multilevel signals on an optical disk, however no one has succeeded in increasing significantly the recording density using this approach. In this paper we present a novel method to obtain a multilevel rf signal by modulating the position of the pit edges. With this method we utilize the theoretically available SNR margins not yet implemented in current optical disk systems. Thus we can achieve higher recording densities even when using a conventional pick-up.

© 1994 Optical Society of America