| 摘要 |
PURPOSE:To acknowledge an end edge of an information magnetic domain with high accuracy by using S-polarization component of the magnetic Kerr effect to be generated by a magneto- optical recording film. CONSTITUTION:A light spot 5 is projected upon a boundary 17 of the information magnetic domain in an information track. The direction of an electrical field vector on incident flux of light 13 is 16, and the magnetization directions 18 and 19 are opposite to each other with the end edge 17 as their boundary. The magnetic Kerr effect due to magnetization 18 is received by the light in an area 5-1, and its corresponding reflected light 20-1 is given the Kerr rotation so that its electrical field vector becomes 21, and then this S-polarization component becomes 22. Meanwhile, the light of the other area 5-2 is given the magnetic Kerr effect due to magnetization 19, and its corresponding reflected light 20-2 is rotated in a deflection plane in the direction opposite to the light 20-1 to be an electrical field vector 23, and its S-polarization component is 24. When the light beams 20-1 and 20-2 having their phase difference pi are passed through a lens 4 and imaged by a sensor lens 10, an amplitude distribution 25 having O in a central part is shown, and an intensity distribution 26 shows darkness in the central part, while the head part size is approximately the same as the size of an Airy disk to be settled by resolution depending upon the lenses 4 and 10. By this constitution, the magnetic domain boundary is read out with high accuracy, and the information is optically reproduced. |
