PHASE PLATE AND OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE

摘要

A small, lightweight phase plate having a high area division accuracy and having the same action as a bisect polarization rotator and an optical information recording/reproducing device for stable recording and reproduction are disclosed. The phase plate (P1) has a polymer liquid crystal film (2) held between transparent substrates (1, 4). The polymer liquid crystal film (2) is spatially divided in the area irradiated with an incident light in such a way that the polarization of a light passing through the phase plate differs depending on the difference of the alignment direction of the polymer liquid crystal film (2). The phase plate (1) is incorporated in an optical information recording/reproducing device as a bisect polarization rotator.