Wavefront aberration correction unit, optical pickup and wavefront aberration correction device

摘要

An LCD panel will rotate based on an external control signal by a prescribed angle such portion of light flux, that enters an objective lens, corresponding to a predetermined incident point and, at the same time, will change by a prescribed length an optical path of this portion of optical flux whose aberrations are in excess of a prescribed standard value. It is thus possible to compensate the wave-front aberrations due to the differences in the effective optical-path length and also to control the effective numerical aperture of the objective lens by utilizing linearly polarized light as the light to be emitted from the laser beam source. It is also possible to compensate the aberrations due the differences in the substrate thickness of the optical recording medium and those due to a tilt of the optical recording medium.