Abstract

A high density optical disk format named DVD adopts a 0.6 mm disk to simultaneously use a high numerical aperture (NA) lens and gain tolerance of disk tilt.¹ Because of the immense popularity of the CD format, it is important to playback the current widely used Compact Discs (CDs) on DVD format players. This requires an optical head that can read both conventional 1.2 mm disks and the new 0.6 mm disk. To read both disks with the same optical head, it is necessary to overcome spherical aberration caused by the difference in disk thickness.

© 1998 Optical Society of America