| 摘要 |
PURPOSE:To obtain the optical information recording and reproducing device which can detect a magneto-optical signal and is reduced in size and weight by providing a polarized light separating function. CONSTITUTION:The light emitted from a semiconductor laser 9 is made incident on a diffraction grating 11 for forming 3 beams of a luminous flux separating element 10, by which the light is split to three beams; zero order light 17a, +1st order light 17b and -1st order light 17c. The luminous fluxes split to the 3 beams advance in a substrate 13 and are made incident on the diffraction grating 14 for optical branching and are further distinctly separated to the three beams. All the luminous fluxes which are split to the 3 beams by transmitting the diffraction grating 14 for optical branching of a luminous flux separating element 10 transmit a collimating lens 16. Only the zero order light 17a is collimated to collimated beams of light at this time and these beams advance successively. Of these beams, the three luminous fluxes are condensed by an objective lens 32 and are projected to the surface of a magneto-optical disk, by which the recording of information, etc., is executed. The magneto-optical signal is simultaneously detected in addition to a focus error signal and a track error signal in this way. |
