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
Full Article | PDF ArticleMore Like This
Bruce E. Bernacki and M. Mansuripur
Appl. Opt. 33(5) 735-743 (1994)
Seiji Nishiwaki
Appl. Opt. 29(5) 644-653 (1990)
Michael R. Descour, Daniel I. Simon, and Wei-Hung Yeh
Appl. Opt. 38(8) 1388-1392 (1999)