The optical multilayer structure may be obtained by stacking, on a substrate made of a metal such as chromium (Cr), a first transparent layer made of a material having a high refractive index such as TiO2 (n=2.40), a second transparent layer made of a material having a low refractive index such as MgF2 (n=1.38), a gap portion having a changeable size capable of causing an optical interference phen