| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical recording and reproducing medium capable of easily realizing multilayering of a signal recording layer and increasing a recording capacity, an optical reproducing device and an optical reproducing method. <P>SOLUTION: On the surface of the signal recording layer 12, a projection part 13 is formed. Thus, the signal recording layer 12 is provided with a part having a first thickness d1 and a part having a second thickness d2 larger than the first thickness d1. For instance, at the time of taking the first thickness d1 in the signal recording layer 12 as a coherent length Lc and the second thickness d2 as the double of the coherent length Lc, cumulative light intensity in higher harmonic light 44a becomes maximum and the cumulative light intensity in higher harmonic light 44b becomes minimum. By identifying the thickness change (d1 or d2) of the signal recording layer 12 by the light intensity change of the higher harmonic light 44, signals recorded as the thickness change (d1 or d2) of the signal recording layer 12 composed of a nonlinear optical material are reproduced. <P>COPYRIGHT: (C)2004,JPO |
