Patent ID: 7554894

Claim:
A data recording and readingout system comprising: an optical recording medium having a layered structure including a recording layer, an optical absorption layer and at least one dielectric layer between said recording layer and said optical absorption layer, said optical recording medium being configured to record data by a recorded mark train including a plurality of recorded marks; and a data recording and readingout apparatus comprising a light source which irradiates a laser beam having a wavelength λ an objective lens positioned to receive said laser beam from said light source and a solid immersion lens positioned to receive said laser beam from said objective lens, said objective lens having a numerical aperture NA defined from 0.4 to 0.6, said solid immersion lens having a refractive index n defined from 1.5 to 2.5, said data recording and readingout apparatus being configured to record or read out said data from said optical recording medium by irradiating said optical recording medium with said laser beam having a limit of resolution satisfying λ/(4·n 2 ·NA) via said objective lens and said solid immersion lens such that said optical recording medium makes each of said recorded marks which is smaller or equal to said limit of resolution.