| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical head reducing cost, improving environment resistance and moreover realizing miniaturization. SOLUTION: The light beam from a light generating means 1 is reflected with a polarizing beam splitter 2 and condensed on a medium 6 with a lens 5 via a polarizing diffraction element 3, 1/4 wavelength plate 4. One part of the reflecting light beam from the medium 6 is diffracted with the polarizing diffraction element 3 and received with a light detecting means 7 transmitting the polarizing beam splitter 2. The light generating means 1 is unnecessitated to arrange in the vicinity of the light detecting means 7 by providing with the polarizing beam splitter 2, and even though the diffraction angle of the polarizing diffraction element 3 is not made large, the distance among the polarizing diffraction element 3, light detecting means 7 and light generating means 1 is shortened and miniaturization is allowed. |
