Optical properties of wavelength shifting panels

Abstract

This paper describes the determination of the optical properties of the Bicron wavelength shifting acrylic plastic (BC-480) that absorbs ultraviolet radiation and then reemit it in the visible part of the spectrum. The refractive index and the attenuation coefficient as a function of wavelength were determined from transmission and reflection data. The reemitted visible spectrum was accurately measured using an optical multichannel analyzer and the quantum efficiency of the photoluminescence (the ratio between the number of emitted photons to the absorbed photons) was determined at different wavelengths in the ultraviolet. Finally, these results are applied to determine the effectiveness of this wavelength shifting panel as a means of detecting the ultraviolet component of the Cherenkov spectrum produced by a relativistic particle in water.