Abstract
Aluminum surface mirrors with and without protective coatings of SiO or MgF2 were prepared under various evaporation conditions. The spectral reflectance of these mirrors was measured soon after their preparation in the wavelength region of 0.4-14μm. Then, they were stored in five different surrounding conditions for six months (two serieses of three months storage). After every three months storage, the reflectance was measured to obtain its change during the storage period. Data of the spectral reflectance measurement for the above mirrors were shown. The reflectance change for the unprotected aluminum mirrors and the MgF2 coated mirrors was little except the reflectance change for the mirrors stored in saturated water vapor atmosphere. The SiO coated mirrors showed reflectance increase in the visible and nearinfrared region.
