title: Investigation of certain diffraction effects in an optical disk.
abstract: We report certain diffraction effects that are pertinent to the operation of double-layer optical recording media. For simulating cross-talk effects for double layers, the diffraction of light from the out-of-focus layer and the resulting distribution on the in-focus layer are studied by use of computer simulations. The findings are then verified qualitatively by direct measurements. We also describe a technique for analyzing (by computer simulation) the focus-error signal (FES), taking into account the cross talk between two layers, in systems that use the astigmatic method in conjunction with the double-layer disk. The results of our computer simulations of the FES give us a 10% cross-talk contribution to the original signal. The results of the FES evaluation are compared with those measured in an actual disk drive; good agreement between computation and measurement is obtained.
authors.forename: J H
authors.initials: JH
authors.lastname: Yoo
authors.forename: C W
authors.initials: CW
authors.lastname: Lee
authors.forename: D H
authors.initials: DH
authors.lastname: Shin
authors.forename: C
authors.initials: C
authors.lastname: Bartlett
authors.forename: K L
authors.initials: KL
authors.lastname: Cheong
authors.forename: J K
authors.initials: JK
authors.lastname: Erwin
authors.forename: M
authors.initials: M
authors.lastname: Mansuripur