Vector diffraction analysis of optical disk readout

The optical disk readout signals from ROM disks are presented by use of a r igorous three-dimensional vector diffraction method. The optical disk is mo deled as a crossed metal grating without restriction on the form of the inf ormation maths, and the permittivity of the metal is taken into account. Th e diffracted held from the disk is obtained by means of decomposing the foc used incident beam into a spectrum of plane waves and then calculating the diffracted plane waves for each respective incident component. The readout signal is obtained by integration of the energy-flux density of the diffrac ted ddd according to the detection scheme of the optical disk system. A typ ical digital versatile disk (DVD) system is applied with this theory, and t he result is far from that of scalar diffraction theory. (C) 2000 Optical S ociety of America OCIS codes: 210.4590, 050.1960.