| 摘要 |
PROBLEM TO BE SOLVED: To attain miniturization of a pickup by enabling semiconductor lasers of two different wavelengths to be arranged within a same laser package and unnecessitating a beam splitter due to the function of a hologram element. SOLUTION: In a hologram laser constituted by arranging plural semiconductor lasers of different wavelengths 6-1, 6-2 and at least one photodetector within the one laser package 5 and to arrange the hologram element on the upper surface of the laser package 5, a hologram pattern 9 applied on the hologram element 8 is constituted to set the pitch of alternately formed diffraction gratings in accordance with the wavelength of the semiconductor laser and to use lights 16-1, 16-2 emitted from plural semiconductor lasers arranged within the laser package 5 as the same optical axis 17. |
