A recording medium according to one embodiment of the present disclosure includes a recording layer and an optical thin film. The recording layer includes a heat-sensitive color-developing composition and a photothermal conversion material. The photothermal conversion material absorbs a wavelength in an infrared region and generates heat. The optical thin film is provided on one surface of the recording layer. The optical thin film reflects the wavelength in the infrared region and transmits a wavelength in a visible region.

An information recording medium includes three or more information layers. The three or more information layers include a first information layer including a first dielectric film, a recording film, and a second dielectric film in this order. The first dielectric film contains an oxide of D1. The D1 represents at least one element selected from a first group consisting of Nb, Mo, Ta, W, Ti, Bi, and Ce. The recording film contains at least W, Cu, Mn, and oxygen and M. The M represents at least one element selected from a second group consisting of Nb, Mo, Ta, and Ti. The W, the Cu, the Mn, and the M except the oxygen in the recording film satisfy a following formula (1):

W.sub.xCu.sub.yMn.sub.zM.sub.100-x-y-z (atom %)(1) wherein x, y, and z satisfy 15x60, yz, 0<z40, and 60x+y+z98.

A dielectric layer is formed from an oxide containing Sn and at least one of Zn, Zr, Si and Ga. The molar percentages of Sn, Zn, Zr, Si, and Ga, relative to the total elements in the oxide, represented by a, b, c, d, and e, respectively, satisfy the conditions (1)-(7): (1) 0b/(a+b)0.6, (2) 0(c+d)/(a+b+c+d+e)0.5, (3) 0b50, (4) 0c40, (5) 0d45, (6) 0e40, and (7) 20b+c+d+e80. The dielectric layer enables favorable information recording in an oxide-based recording layer on which the dielectric layer is directly overlaid, does not require preventive measures for health hazard, and is superior in durability.

An optical recording medium includes a plurality of information signal layers, and at least one of the plurality of information signal layers other than the farthest information signal layer from a light irradiation surface includes: a recording layer; a first dielectric layer provided on a side opposite to a light incident side of the recording layer; and a second dielectric layer provided on the light incident side of the recording layer. The first dielectric layer and the second dielectric layer include indium oxide and tin oxide, and the atomic concentration of tin in the first dielectric layer is higher than the atomic concentration of tin in the second dielectric layer.

An optical recording medium includes a plurality of information signal layers, and at least one of the plurality of information signal layers other than the farthest information signal layer from a light irradiation surface includes: a recording layer; a first dielectric layer provided on a side opposite to a light incident side of the recording layer; and a second dielectric layer provided on the light incident side of the recording layer. The first dielectric layer and the second dielectric layer include indium oxide and tin oxide, and the atomic concentration of tin in the first dielectric layer is higher than the atomic concentration of tin in the second dielectric layer.

An optical recording medium includes a plurality of information signal layers, and at least one of the plurality of information signal layers other than the farthest information signal layer from a light irradiation surface includes: a recording layer; a first dielectric layer provided on a side opposite to a light incident side of the recording layer; and a second dielectric layer provided on the light incident side of the recording layer. The first dielectric layer and the second dielectric layer include indium oxide and tin oxide, and the atomic concentration of tin in the first dielectric layer is higher than the atomic concentration of tin in the second dielectric layer.