OPTICAL INFORMATION MEDIUM MEASUREMENT METHOD

PROBLEM TO BE SOLVED: To provide an optical information medium measurement method that achieves accurate comparison of modulation degree or reflectance difference even when any measuring optical system measures an optical information medium without preparing a special measuring optical system. SOLUTION: The optical information medium measurement method is used for measuring a degree of modulation in the optical information medium with a multilayered structure having multiple information layers. The optical information medium measurement method includes: a first step of measuring the modulation degree of each layer of the optical information medium by using the measurement optical system; a second step of obtaining a thickness between layers of the optical information medium; a third step of obtaining a reflectance of each layer of the optical information medium; and a fourth step of converting the modulation degree of each layer, the modulation degree being measured in the first step, into a modulation degree at a reference optical system different from the measurement optical system. COPYRIGHT: (C)2011,JPO&INPIT