| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact and low cost optical head capable of using a polarizing optical system for a plurality of light sources having different wavelengths, respectively. SOLUTION: This optical head is provided with a plurality of light sources 1A, 1B having different wavelengths, light collecting optical systems 4, 6 collecting light of the light sources on an optical recording medium 7, an optical element 5 arranged in a light path from the light sources to the optical recording medium, separation means 2A, 2B separating reflection light from the optical recording medium from a light path of light emitted from the light sources, and light detectors 8A, 8B, 9A, 9B receiving the separated reflection light from the optical recording medium. Retardation of the optical element 5 is set in such a way that it becomes substantially an odd number multiple of 1/4 wavelength for wavelengths of any light source. |
