| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for erasing information of an optical recording medium capable of erasing only information of a desired area of the recording layer of the optical recording medium using photo-refractive material. SOLUTION: The device for erasing information of the optical recording medium is provided with at least a light source emitting erasing light to the recording layer of the optical recording medium using photo-refractive material, a means for condensing the erasing light in the recording layer, and a modulating means for modulating the erasing light. In the modulated erasing light, σ4/σ2 obtained from a secondary moment σ2 and a quaternary moment σ4 of an irradiating quantity from the pit center in the surface 1 orthogonal to the optical axis satisfies 0<(σ4/σ22)<3. |
