Using thin-film optical filters to select a single wavelength band, the filters are usually completed by color glasses that reject the unwanted wavelength regions by absorption. However, high power of illumination makes it impossible to reject radiation by absorption without the risk of damage to the color glasses. In this case, the rejection of radiation has to be made by reflection on the filter. With UV applications, an additional problem occurs because of absorption loss in the thin-film materials used. mso jena now offers low-loss thin-film optical filters based on HfO2 and SiO2 thin films as OEM solutions for UV optics in the wavelength region l > 230 nm. An advanced deposition technology helps to manufacture single-substrate all-dielectric UV filters with band transmittance up to 97 percent and blocking exclusively by reflectance. In addition, the ion-assisted deposition technology provides for high-stable optical coatings under alternating temperatures without any moisture shift. Excellent experience in thin-film design and the application of the latest version of OptiLayer thin-film design software complements the deposition technology and gives the basis to offer all types of filters, beam splitters, polarizers, mirrors and AR coatings as well as dual band UV-VIS coatings, based on the same HfO2/SiO2 technology.