| 摘要 |
PURPOSE:To attain miniaturization by providing a photodetector with photodetecting elements receiving three beams passing through a Wollaston prism separately respectively on one and same face so as to use only one component thereby separating beams and detecting the polarized state. CONSTITUTION:The light passing through a Wollaston prism 10 is separated into two beams 300, 400 whose intensity is changed depending on the polarized state at the incidence and into one beam 500 whose intensity is unchanged depending on the polarized at the incident light. The photodetection elements 21-23 receiving each beam are arranged on one and same face of the photodetector 11. The tilt of the major axis of two prisms 31, 32 constituting the Wollaston prism 10 is adjusted to increase the sum of the luminous intensity of the two beams 300, 400 causing the intensity change due to the polarized state more than the luminous intensity of the beam 500 whose intensity is unchanged due to the polarization. Thus, the optical head capable of detecting and reproducing the information recorded magneto-optically with high sensitivity and simple constitution is obtained. |
