| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical recording medium whose contrast is high without being more dependent on the thickness of a dielectric layer in a short wavelength area by specifying the laminating order of the dielectric layer, a recording layer and a reflection layer and the refractive index of a first dielectric layer. SOLUTION: This recording medium performs the recording and the erasing of information by the phase transition between a non-crystalline phase and a crystalline phase due to the irradiating of a light beam whose wavelength is not larger than 550nm. At least, a first dielectric layer, a recording layer, a second dielectric layer and a reflection layer are laminated in this order and the refractive index (n) of the first dielectric layer is made to be the range of 1.4-2.1. Or, it is preferable that the wave-length of a light to be irradiated is made not to be larger than 450nm and the refrative index (n) of the first dielectric layer with respect to this wavelength is made to be in the range of 1.4-1.8. since the fluctuation of a refractive index and a contrast due to the thickness of the dielectric layer is very small, the thickness of the layer is not restricted especially. |
