Abstract

A lens made of a birefringent material shows two focal points. If the polarization of incident light is switched periodically and a detector is placed between the two focal points, this property can be utilized to detect a focus error signal equivalent to that of a dual detection optics. The proposed system offers the possibility to achieve amplitude detection for the focus error. It results in a compact optical pickup with reduced adjustment requirements. A second possible pickup uses a birefringent lens and a Wollaston prism. In this case, a compact dual detection method is achieved.

© 1990 Optical Society of America

Causes of focus-error feedthrough in optical-disk systems: astigmatic and obscuration methods

Bruce E. Bernacki and M. Mansuripur
Appl. Opt. 33(5) 735-743 (1994)

Bit error analysis for optical disks

Seiji Nishiwaki
Appl. Opt. 29(5) 644-653 (1990)

Ring-toric lens for focus-error sensing in optical data storage

Michael R. Descour, Daniel I. Simon, and Wei-Hung Yeh
Appl. Opt. 38(8) 1388-1392 (1999)

Waveguide optical deflector for an optical disk tracking actuator using a surface acoustic wave device

Akira Arimoto, Kouji Muraoka, Takeshi Shimano, Kazuto Senda, and Sachiko Ishikawa
Appl. Opt. 29(2) 247-250 (1990)

Computer simulations of effects of disk tilt and lens tilt on push-pull tracking error signal in an optical disk drive

Chanda L. Bartlett, David Kay, and M. Mansuripur
Appl. Opt. 36(32) 8467-8473 (1997)