| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical apparatus such as a laser coupler capable of obtaining stable output characteristics by constantly offsetting thermal characteristics for a light beam of an arbitrary wavelength, even in the case plural laser elements are monitored with a PD of the same characteristics; and also to provide an optical disk device using this apparatus. SOLUTION: Among the outgoing laser beams L1, L2 of plural laser diodes LD1, LD2, in one laser beam L1 (e.g. with a wavelength of 780 nm), the protective film 53 of the laser end face is provided with such a reflection characteristic as offsets the thermal characteristics of a PD for monitoring; and, in addition, an optical film 54, in which reflectivity for the other laser beam L2 (e.g. with a wavelength of 650 nm) increases at the time of rising temperature, is provided in the optical path between the plural laser diodes LD1, LD2 and the plural photodiodes 16, 17 and 18, 19, particularly on the spectral surface 20a of a prism 20. |
