%0 Journal Article
%T Optical properties of bialkali photocathodes
%A Dario Motta
%A Stefan Schoenert
%J Physics
%D 2004
%I arXiv
%R 10.1016/j.nima.2004.10.009
%X The optical properties of the `bialkali' KCsSb and RbCsSb photomultiplier cathodes have been experimentally investigated in the visible range. The measurements carried out include the absolute reflectance at near-normal incidence, the polarization-dependent relative reflectance at various angles and the change in polarization upon reflection from the photocathode. These experimental inputs have been combined with a theoretical model to determine the complex refractive index of the photocathodes in the wavelength range 380 to 680 nm and their thickness. As a result of this work, we derive a model which predicts the fraction of light impinging on a photomultiplier tube that is reflected, absorbed or transmitted, as a function of wavelength and angle, and dependent on the medium to which the photomultiplier is coupled.
%U http://arxiv.org/abs/physics/0408075v1