Ultraviolet filters for sensors matching biological action spectra

A considerable interest is growing worldwide about the photobiological effects of the ultraviolet radiation; in fact, it has been demonstrated that ultraviolet radiation can affect both human health as well as the equilibrium of entire ecosystems. The relative effectiveness of ultraviolet radiation at a particular wavelength in producing a specific biological response is defined by an action spectrum. Broadband radiometers characterized by having a spectral response that matches an action spectrum allow the measure of the effective irradiance associated to an ultraviolet source. In this work we present the designs of interference filters to be used in radiometric heads. Their optimized transmission curve coupled to the spectral response of different ultraviolet photodiodes provides the match of the sensor spectral response with some selected action spectra. Development of instruments for the measurement of the effective solar irradiance is foreseen. The design of interferential filters which transmittance curve was optimized in order to match a target biological action spectrum is here presented.