Abstract: An object of the invention is to provide a method for preparing an optical recording medium, featuring a high production yield, a reduced loss and a high utilization of dye solution, and ensuring to produce media of consistent quality even by continuous coating as well as an optical recording medium. The object is achieved by a method for preparing an optical recording medium, comprising the step of applying a solution of a dye in a solvent onto a resin substrate to form a dye film, wherein the solvent of the dye solution is a mixture of tetrafluoropropanol and/or octafluoropentanol with an aliphatic saturated alcohol of 1 to 4 carbon atoms, and a recording layer is formed by applying the dye solution.

Abstract: In an optical recording medium using writing and reading light having a wavelength of up to 690 nm and having a recording layer and preferably a reflective layer, the recording layer contains a chelate compound having an azo compound of specific structure as a ligand (i.e., azo metal complex dye). This results in an optical recording medium of the heat mode having advantages including the dye's sufficient solubility in a coating solvent which does not attack polycarbonate substrates and improved write/read characteristics with light having a wavelength of up to 690 nm.

Abstract: An optical recording medium is provided in which a recording layer contains a salt-forming dye between an ion of an azo metal complex of the following formula (I) and an ion of a cyanine dye of the following formula (II), having a complex index of refraction in the wavelength region of recording light and/or reading light whose imaginary part k is up to 0.20, or at least one of azo oxovanadium metal complexes having an azo compound of the following formula (III) as a ligand and metal complexes having azo compounds of the following formulae (IV) and (V) as a ligand. Recording and reading can be carried out at a conventional wavelength or a short wavelength of about 630-690 nm or both.

Abstract: An optical recording medium which can be recorded and read at a short wavelength (about 635-680 nm) or which can be recorded and read at two wavelengths, the short wavelength and a conventional wavelength (about 780 nm) has a recording layer containing an azo metal complex dye obtained by reacting a metal compound with an azo compound of formula (I) or an azo compound of formula (II). ##STR1## In formula (I), Q.sub.1 is a group of atoms necessary to form an aromatic ring with two C, A is C or a hetero-atom, Q.sub.2 is a group of atoms necessary to form an aromatic ring with two C and A, and Q.sub.3 is a group of atoms necessary to form an aromatic ring with C, N and A, fused to the aromatic ring completed by Q.sub.2. In formula (II), Q.sup.1 is a 8-quinolyl radical and Q.sup.2 is a 2-imidazolyl radical whose nitrogen at the 1-position has active hydrogen.

Abstract: The invention provides an optical recording medium comprising at least two recording layers containing a dye. At least two layers of the recording layers have different optical constants, and at least one among these recording layers having different optical constants contains a dye which forms a thin film having an absorption spectrum whose half-value width is up to 170 nm. This construction permits the medium to be written and read in a conventional wavelength range of about 780 nm and a shorter wavelength range of about 630-680 nm.