Reducing Interlayer Crosstalk in Reading Multilayer Disc for Compact Optical Pickup Using Polarizing Filter

We proposed an interlayer crosstalk reduction device that can be used in an optical pickup based on the astigmatic aberration method. The device has two wave plates covering the half plane at different positions on the optical axis and an analyzer, and is placed in the beam of astigmatic aberration. We can make the polarization state of the beam after transmission of the two wave plates different according to whether the focal line position is situated between the two wave plates. We measured the device transmission and confirmed that the optical characteristics agree well with the simulation.