A tuneable, narrow-band, high-intensity UV source

More potent narrow-band UV sources need to be developed to determine the in vivo action spectra of long-term UV effects, such as photocarcinogenesis. This article describes the development of a potent, narrow-band UVB source, an Oriel solar simulator modified by the use of newly developed all-dielectric interference (ADI) filters. The sharp cut-off edges and high levels of transmission are unique features of these filters. Further, they can be produced as long-wave-pass or short-wave-pass filters with maximum transmittance at any given wavelength. The simulator is equipped with up to 4 ADI filters and potentially emits narrow UV bands. The filter combinations for narrow bands allow transmission of up to 80% of the incoming radiation. There was a homogeneous intensity area of 25 X 25 cm at a distance of 150 cm from the source in the centre of the irradiation field. The average intensity of UV available in narrow bands of UV (with a minimum half-band width of 11 nm) was 140 mW/m2. These values are sufficient to determine action spectra in groups of live animals (mice).