| 摘要 |
<p>A recordable optical recording medium comprising a recording layer containing an organic dye which can absorb a laser beam and a metal reflective layer directly or via another layer on a transparent supporting substrate having a pre-groove and a pre-pit, wherein the organic dye has a refractive index nk of 2.2 or more at a reproduction wavelength lambda2; in relation to the reproduction wavelength lambda2, the depths of the pre-groove and the pre-pit on the substrates are more than lambda2/4; and the following equations are satisfied:wherein r is a recording laser beam diameter represented by lambda1/NA where lambda1 is a recording wavelength [mum] and NA is a numerical aperture for an object lens; wg [mum] and thetagr are a half value width and a cross-section tilting angle in a substrate radial direction for the pre-groove, respectively; and wp [mum], thetapr and thetapt are a half value width, a cross-section tilting angle in a substrate radial direction and a cross-section tilting angle in a tangential direction for the pre-pit, respectively.</p> |
