Optical apparatus

摘要

An optical apparatus includes: a focusing lens that focuses light which is one of recording light being irradiated to an optical recording medium with reference light for recording a hologram and reference light being irradiated to an optical recording medium for reading out a hologram; and a focal position-shifting unit that refracts the light while moving in accordance with a moving speed of the optical recording medium, so as to shift a focal position of the light in the optical recording medium a distance in a thickness direction of the optical recording medium.