Abstract
In a typical optical disk drive, the beam of a semiconductor laser diode is collimated, shaped, polarized, and then sent through an aberration-free, high-NA lens to be focused on the "active" surface of an optical disk. To reach this active surface, the beam must pass through the disk substrate, which is typically a plastic or glass medium of known thickness and refractive index. During recording and/ or erasure, the focused laser beam creates or annihilates certain "marks" in the active region. During readout, the same focused beam, attenuated to avoid recording and/or erasure, picks up the information as represented by marks, and returns to the objective lens. The lens recollimates the beam and sends it to the detection channel, where focus-error, track-error, and data signals are extracted from the returning beam.
© 1996 Optical Society of America
PDF ArticleMore Like This
Seiji Murata, Kenji Asano, Noboru Mamiya, Yoshihisa Suzuki, Seiichirou Takahashi, Akiomi Kunisa, Nobuo Itou, and Kenji Torazawa
OMC.4 Symposium on Optical Memory (ODS) 1996
F. B. McCormick, I. Cokgor, A. S. Dvornikov, M. Wang, N. Kim, K. Coblentz, S. E. Esener, and P. M. Rentzepis
OWB.1 Symposium on Optical Memory (ODS) 1996
T. D. Milster, W. L. Bletscher, E. P. Walker, and E. C. Gage
OFA.5 Symposium on Optical Memory (ODS) 1996