| 摘要 |
PROBLEM TO BE SOLVED: To record with sufficient intensity and to reproduce at a high S/N ratio by using a solid immersion lens. SOLUTION: At recording, a voltage is not applied to a liquid crystal plate 631. Then, all laser beams LB are converged on the bottom surface 634a of a solid immersion lens 634, and by bringing a recording medium RM close to the bottom surface 634a, a near field beam is generated, and such a laser beam LB is controlled, and the information is recorded with sufficient light intensity. At a reproducing time, a prescribed DC voltage is applied to the liquid crystal plate 631. Then, the central part of the laser beam LB is shielded by a polarizing plate 632, and only the beam of the outer peripheral part of the laser beam LB made incident on the bottom surface 634a of the solid immersion lens 634 at an angle larger than a critical angle arrives at the solid immersion lens 634 to generate the near field beam downward it. By reproducing with such a less noise beam, the regenerative signal of the high S/N ratio is obtained. |
