Write-once-read-many optical disk having low-to-high recording property accommodating short wavelength recording

A recording/reproduction method exhibiting a Low-to-High recording property, the method comprising a step of:

• performing a recording/reproduction process on an optical recording medium by using a laser having a wavelength that is no greater than 500 nm;
• wherein the optical recording medium consists essentially of:
• a substrate, a reflection layer, an organic material layer, a light absorption layer, and a cover layer;
• wherein the organic material layer is situated on the substrate and has a thickness of 50 nm to 300 nm, the organic material layer having a light absorption function that is sufficient for recording in a recording/reproduction wavelength range of no more than 500 nm;
• wherein the light absorption layer is situated adjacent to the organic material layer and has a thickness of 5 nm to 150 nm;
• wherein the reflection layer is provided on the organic material layer and has a thickness of from 50 nm to 300 nm;
• and
• wherein the organic material satisfies a relation of (light absorption function of organic material layer in recording/reproduction wavelength area) <(light absorption function of light absorption layer in recording/reproduction wavelength area);
• wherein an unrecorded part of the optical recording medium is configured to exhibit a reflectivity that is lower than a reflectivity of a recorded part of the optical recording medium;
• wherein the light absorption function of the organic material layer is provided solely by a material consisting of a single organic material having:
• a first absorption band situated toward a long wavelength side with respect to the recording/reproduction wavelength range,
• a second absorption band that does not belong to the first absorption band, the second absorption band situated in the vicinity of the recording/reproduction wavelength range, and
• a third absorption band situated toward a short wavelength side with respect to the recording/reproduction wavelength range, the third absorption band exhibiting an absorption greater than an absorption of the first absorption band, wherein the third absorption band has a largest absorption wavelength that is no greater than 300 nm,
• wherein the optical recording medium provides low-to-high recording at a recording power range of from 2 mW to 11 mW at a linear recording speed of 6 m/sec.