OPTICALLY ANISOTROPIC MATERIAL, OPTICAL DEVICE AND OPTICAL INFORMATION RECORDER/REPRODUCER

摘要

An optically anisotropic material having a good durability against light is provided. Further, an optical element having a good durability against light and an optical information writing/reading device employing such an element are provided. The optically anisotropic material is obtainable by polymerizing a polymerizable liquid crystal composition containing at least 5mol% of at least one type of polymerizable compound represented by a general formula CH 2 =CR 1 -COO-K-Cy-Cy-L-OCO-CR 2 =CH 2 . A phase difference plate 4 produced by employing the optically anisotropic material has a good durability against light, and accordingly, the phase difference plate 4 can realize an optical heat device suitable for large capacity writing/reading by employing a blue laser as a light source 1.