Optical Pick-up for Blue Optical Recording at NA = 0.85

Sony and Philips have recently developed the basic technology for a 22.5 GB optical recording system, based on a blue laser (#x03BB; = 405 nm) and high numerical aperture (NA = 0.85) objective lens. This system is referred to by the acronym DVR (for Digital Video Recording). In this paper we describe the relization of a compact optical pickup unit capable of writing and reading data on disc according to the DVR format.This paper was originally presented at the 2nd International Conference on Optical Design and Fabrication, ODF2000 which was held on November 15-17, 2000 at the International Conference Center Tokyo Waseda University, Japan.