| 摘要 |
PROBLEM TO BE SOLVED: To dissolve a problem that light transmitting efficiency can not be improved unless the number of parts is increased in a conventional optical pickup. SOLUTION: This optical pickup is provided with a semiconductor laser 1 which emits light having an elliptic far field pattern, a collimator lens 2 which converts light from the semiconductor laser 1 into substantially parallel light, a beam shaping mirror 5 which performs beam shaping by changing a substantial aspect ratio of the far field pattern of light from the collimator lens 2, an objective lens 7 which condenses light shaped by the beam shaping mirror 5 on an optical disk 8, and a photodetector 11 which detects light reflected by the optical disk 8. The beam shaping mirror 5 is arranged so that the substantial major axis direction of the far field pattern is compressed and the cross section of light after beam shaping is gotten close to a circle. Light transmitting efficiency is improved without increasing the number of parts by using such a beam shaping mirror 5. |
