Optical recording medium, and, method and apparatus for optical recording and reproducing using optical recording medium

A method for recording and reproducing comprising:

• irradiating a light having a wavelength of from 630 nm to 700 nm to the optical recording medium at the surface of the substrate, and
• performing at least one of the recording and reproducing of signal information in the recording layer,
• wherein the optical recording medium comprises
• a grooved substrate wherein a guide groove has a depth of 100 nm to 250 nm, and
• at least a recording layer disposed on the substrate in which the recording layer comprises at least one type of formazan-metal chelate dyes represented by the following formula (1):
• wherein a ring “α” represents any one of a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a thiadiazole ring and an imidazole ring, which may be substituted by a substituent;
• “A” represents any one of an alkyl group which may contain a substituent, an unsubstituted aryl group, an aryl group containing another substituent than a fluorinated alkyl group, an alkenyl group which may contain a substituent and a heterocycle residue which may contain a substituent;
• “R” represents one of a fluorine atom and a fluorinated alkyl group;
• “m” is a natural number representing the number of “R” and when “m” is 2 or more, “R”s may be the same or different from each other;
• “M” represents one of a metal atom and a metal compound;
• and “n” represents the number of a formazan ligand coordinating “M” and is one of 1, 2 and 3.