| 摘要 |
PROBLEM TO BE SOLVED: To provide a light receiving and emitting element which is constituted small in size and light in weight and with a low cost and also in which recordings and reproductions of two kinds of optical disks whose, for example, wavelengths and intensities or the like are different are made to be correctly performed and an optical pickup and an optical disk device in which the element is used. SOLUTION: This element includes two light receiving and emitting parts 30, 40 which are arranged by being lapped in two stages with each other and respective light receiving and emitting parts 30, 40 are provided with light receiving elements 35, 36, 45, 46 formed on first semiconductor substrates 41, 42 light emitting elements 33, 43 formed on second semiconductor substrates 32, 42 mounted on the first semiconductor substrates 41, 42 and light branching means 34, 44 guiding respective light beams emitted from the light emitting element 33, 43 to prescribed horizontal directions and also guiding return lights from prescribed directions to the light receiving elements. Then, the light receiving and emitting element 21 is constituted so that light emitting elements of respective light receiving and emitting parts 30, 40 emit light beams whose kinds are different with each other. |
