Abstract

Digital information in optical data storage systems can be encoded in the intensity, in the polarization state, or in the phase of a carrier laser beam. Intensity modulation is achieved at the surface of the storage medium either through destructive interference from surface-relief features (e.g., CD or DVD pits) or through reflectivity variations (e.g., alteration of optical constants of phase-change media). Magneto-optical materials make use of the polar magneto-optical Kerr effect to produce polarization modulations of the focused beam reflected from the storage medium. Both surface-relief structures and material-property variations can create, at the exit pupil of the objective lens of the optical pickup, a phase modulation (this, in addition to any intensity or polarization modulation or both). Current optical data storage systems do not make use of this phase information, whose recovery could potentially increase the strength of the readout signal. We show how all three mechanisms can be exploited in a scanning optical microscope to reconstruct the recorded (or embedded) data patterns on various types of optical disk.

© 2002 Optical Society of America

Analysis of the effects of disk tilt on the differential-phase-detection signal in a high-density DVD read-only disk driver

Quanhong Shen and Duanyi Xu
Appl. Opt. 45(17) 3998-4004 (2006)

Optical readout for optical storage with phase jump

Weidong Zhou and Lilong Cai
Appl. Opt. 38(23) 5058-5065 (1999)

Vector diffraction from subwavelength optical disk structures: two-dimensional modeling of near-field profiles, far-field intensities, and detector signals from a dvd

Wei-Chih Liu and Marek W. Kowarz
Appl. Opt. 38(17) 3787-3797 (1999)

Evanescent coupling in magneto-optical and phase-change disk systems based on the solid immersion lens

Wei-Hung Yeh and M. Mansuripur
Appl. Opt. 39(2) 302-315 (2000)

Measurements and simulations of differential phase-tracking signals in optical disk data storage

Chubing Peng, Wei-Hung Yeh, and M. Mansuripur
Appl. Opt. 37(20) 4425-4432 (1998)