Apparatus and method for optimizing performance in read/write head of an optical storage system with a magneto-optical storage medium

摘要

In a read/write head for a magneto-optical storage system, a general wave plate is positioned between the partial polarization beam splitter to which the radiation from the source is applied and the analyzing beam splitter which directs the two components of the radiation beam to the differential detection system. Using the techniques herein described, equations are developed which identify the optimal parameters for the general wave plate. The equations are derived for the retardation of the general wave plate and for the angle of the slow axis of the general wave plate relative to the read/write head optical coordinates. These two equations are given in terms of the phase between the s and the p polarization components. The equations are applied to the specific example wherein TbFeCo is the magneto-optical material. The inclusion of a liquid crystal element having a voltage controlled retardance permits the read/write head to be used with "write once" optical storage media as well as magneto-optical storage media.