| 摘要 |
PROBLEM TO BE SOLVED: To improve an S/N by providing a reproduction supporting layer for reproduction with a spot smaller than a light converged spot and performing reproduction while fetching light, which is reflected at a certain angle larger than a light converging angle, as detection light. SOLUTION: The beam diameter of reproducing light made incident on an objective lens 51 is set smaller than the diameter of the objective lens 51. This beam diameter can be provided by reducing the diameter of a collimator lens rather than the diameter of the objective lens in the case of shaping reproducing light radiated from a light source with the collimator lens. In this case, since reflected light is radiated from a super-resolution spot 50b in an area smaller than an ordinary spot 50a, the reflected light is radiated at the angle larger than the light converging angle of reproducing light. Since the objective lens 51 has the diameter larger than the beam diameter of reproducing light to be made incident, the light reflected at the angle larger than the light converging angle of reproducing light can be fetched. |
