Photoluminescence from white reference materials for spectral diffuse reflectance measurements upon exposure to radiation shorter than 400 nm

Photoluminescent properties of white reference materials commonly used as spectral diffuse reflectance standards were studied in the near-UV to visible region. Spectroscopic analysis based on a two-monochromator method revealed that most of white reference materials produced photoluminescence upon exposure not only to near-UV and UV radiation but also to visible radiation shorter than 400 nm. Remarkable differences in the photoluminescence spectrum and intensity were observed between different types of white materials, which would suggest that each material has a specific origin of photoluminescence. Although most of the photoluminescence observed in this study was slight except for some kinds of opal glasses and ceramic tiles, it would cause a relatively large error in spectral diffuse reflectance measurements, depending on the measurement conditions such as the spectral responsivity of detector systems.