New Optical Storage Head Using Grating Lenses
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
The conventional optical head for magneto-optic read/write optical storage, as shown in Fig. 1, suffers two key deficiencies. First, it needs a partial polarization beam splitter (PPBS) for the focus and track servo signals. The partial polarization beam splitter can reduce the total throughput of the head by 20 to 30 percent. Secondly, the minimum head profile is limited by the sum of the beam diameter and the focusing lens focal length. The head profile height is important for the volumetric density consideration of the optical storage. The weight of the focusing element plus the attached actuator will determine the speed of the head.