| 摘要 |
PURPOSE:To allow the recording with high C/N by a bubble mode by irradiating the medium with a laser beam from a substrate side to form cavities by the bulging of a reflecting layer and the depressing of a recording layer at the boundary between the recording layer and the reflecting layer, thereby forming the cavities having the depth in a specific range and recording information. CONSTITUTION:The bubbles are formed in the recording layer by irradiating the recording layer with the laser beam from the substrate 42 side to form the bulging parts on the reflecting layer 43 side and the depressing parts 46 on the recording layer 42 side at the boundary between the recording layer 42 and the reflecting layer 43, by which the cavities 46 are formed and the recording of the information is executed. The cavities 46 are so formed that the depth thereof, i.e. the max. value of the perpendicular distance between the surface of the recording layer 42 and the base of the reflecting layer 43 attains the lambda/15 to lambda/4 range (where lambda is the wavelength of the laser at the time of reproduction). The distortion of the waveforms of the signals obtd. in such a manner is decreased and the high C/N is obtd. at the time of reproduction. The recording with the high C/N by the bubble mode is possible in this way. |
