| 摘要 |
PROBLEM TO BE SOLVED: To provide the light emitting device and the light receiving and emitting element which are small in the size, light in the weight and low in the cost and correctly conduct a recording and reproducing of two kinds of optical disks different in wavelength, strength, etc., and to provide the optical pickup and the optical disk device using the light emitting device and the element. SOLUTION: The device is provided with light receiving elements 21g and 21h formed on a first semiconductor substrate 21a, a first light emitting element 21b formed on a second semiconductor substrate 21b mounted on the substrate 21a, a second light emitting element 21d mounted on the element 21b and arranged to emit the light beams, which are almost parallel to those from the element 21b and have a different kind from the element 21b, and an optical branching means 21e which guides the light beams emitted from the elements 21b and 21d to a prescribed direction and guides the light beams from a prescribed direction to the elements 21g and 21h. |
