Multilayer optical recording medium with interfacial surfaces

A multilayer optical recording medium comprising:

• a plurality of interfacial surfaces configured to reflect an incident light beam, neighboring ones of the interfacial surfaces having a spacer therebetween;
• wherein,
• when a light incident surface side is an upper surface side, a different thickness layer unit including the spacers having different thicknesses arranged sequentially is disposed on the lowermost layer side and the spacers each having a thickness different from the thickness of any one of the spacers arranged in the different thickness layer unit are sequentially arranged above the different thickness layer unit,
• the different thickness layer unit includes three types of spacer having different thicknesses arranged therein,
• a plurality of equal-thickness layer units each including spacers having the same thickness sequentially arranged therein are formed above the different thickness layer unit, and
• the thickness of the spacers arranged in one of the equal-thickness layer unit differs from the thickness of the spacers arranged in any one of the other equal-thickness layer units.