| 摘要 |
PROBLEM TO BE SOLVED: To provide a hologram laser and an optical pickup using it, capable of detecting respective laser beams by one light-receiving element and capable of obtaining a correct focus error signal by outputting laser beams which have plural different wavelengths. SOLUTION: The hologram laser 10 is provided with plural semiconductor laser elements 1, 2 exitation light beams which are mutually different in light- emitting wavelength, a signal-detecting photodiode 3 receiving the light beams, and a hologram 51 guiding the light beams to the signal-detecting photodiode 3 by diffracting the light beams. The semiconductor laser elements 1, 2 are disposed, so that optical axes A, B of both light beams become parallel each other and also a dividing line D dividing the light-receiving parts 3a, 3b of the signal detecting photodiode 3 and the optical axes A, B of the light beams of the semiconductor laser elements 1, 2 are constituted, so as to be on the same plane. |
