Differential phase detection or differential time detection has been adopted as the method for deriving an optical tracking-error signal for the new generation of optical disks with increased density (DVD system). An overview is given of the various methods in the analog and the binary signal domains and of their properties with respect to optical disk structure, mechanical tolerances, and disk defocus.
© 1998 Optical Society of America
Joseph Braat, "Differential Time Detection for Radial Tracking of Optical Disks," Appl. Opt. 37, 6973-6982 (1998)