A SELECTIVE ULTRAVIOLET DETECTOR TUNABLE IN THE 230-430 NM RANGE

The photoluminescence of Eu2+ in doped NaCl crystals is used to detect ultraviolet (UV) irradiance at different wavelengths in the 230-430 n m range. An interchangeable interferential filter, in the path from th e radiation source to the crystal sensor, helps to select the detectio n interval desired, thus ensuring the tunability of the device. The de tectable excitation range of UV light of the proposed device matches t he active excitation regions of UV light in many environmental and bio logical phenomena. The characteristics of the detector (linearity, sen sitivity and reliability) are reported. Finally, an application to det ect uv sunlight at 312 and 365 nm is presented.