Fluorescence of optical filter glass: characterization and measurement results

Optical filter glasses are for example used in spectroscopy to separate the incident light from the measurement signal (light). In order to obtain a good signal-to-noise ratio, the self-fluorescence of optical filter glass should be low. Different optical filter glasses are available for such an application: bandpass filters or longpass filters from UV to near IR light. We will present a measurement set-up for our fluorescence measurements. Afterwards we present for the first time measurement results of the fluorescence for different optical filter glasses at 365 nm excitation. Besides other factors, fluorescence depends on impurities of the starting material of the glass. Due to fluctuations of the starting material used for the glass production the fluorescence of the same filter glass type will fluctuate for different melting campaigns. Thus, results from different melting campaigns will be shown for the same filter glass type. The shown measurement results will enable users of optical filter glass to estimate the amount of fluorescence depending on different filter glass types and to estimate the influence of different glass melting campaigns.