Broad-Band Ultraviolet Filters

Abstract

Three broad-band ultraviolet filters with effective wavelengths of 2680, 2600, and 2210 A are described. The respective transmittances at these wavelengths are 0.16, 0.23, and 0.10, with corresponding bandwidths of 320, 200, and 330 A. The materials used in constructing these filters were interference filters, NiSO4(H2O)6 crystals, KCl:KBr:Pb crystals, Corning filters 9–54 (96% silica), Corning filters 7–54 (red-purple corex A), and cation-X (2, 7-dimethyl-3, 6-diazacyclohepta-1, 6-diene iodide in polyvinyl alcohol films).