| 摘要 |
PURPOSE:To provide a beam splitter capable of simplifying a photodetecting system. CONSTITUTION:This beam splitter is provided with a planar first surface 2 splitting an incident beam to a reflected beam and a transmitted beam, and a second surface 3 having, positive refractive power converging and emitting the transmitted beam. In such a manner, by using the beam splitter having a converging action, a detective optical system in an optical system for an optical head is simplified, and the number of parts constituting the optical head is reduced. |
