| 摘要 |
A monolithic double-wavelength semiconductor laser diode is provided in a DVD/CD compatible player to suppress deterioration in the optical characteristics of a reading light spot. A laser diode is a monolithic element which has two light emitting points (21,22) on a single substrate for emitting two different laser beams having different wavelengths with each other. A central line of a main laser beam for use in reproducing DVDs is positioned closer to the optical axis Y of an optical system than a central line of a laser beam for use in reproducing CDs. In another arrangement, the central line of a main laser beam for use in reproducing DVDs is positioned so as to be coincident with the optical axis Y of the optical system. <IMAGE> |
