High-gain DC-mode operated Gaseous Photomultipliers for the visible   spectral range
  We shortly describe recent progress in photon detectors combining bi-alkali photocathodes and cascaded patterned gas-avalanche electron multipliers. It permitted the development and the first feasibility demonstration of high-gain gaseous photomultipliers sensitive in the visible spectral range, operated in DC mode with single-photon sensitivity. 
A. Lyashenko, A. Breskin, R. Chechik, F. D. Amaro, J. Veloso and   J.M.F. Dos Santos