Optical pickup in which at least one of a reflecting mirror and a beam splitter has a function of a phase difference plate

摘要

In an optical pickup provided with an optical system including a reflecting mirror and a beam splitter, at least one of the reflecting mirror and the beam splitter having a base member and a film member attached to the base member to introduce a phase difference between an incident laser beam and an outgoing beam. A laser beam is emitted or radiated from a semiconductor laser. The laser beam is converged through the optical system to be focused on a signal recording surface of an optical disk. A return beam from the signal recording surface is detected through the optical system by a photodetector.