Abstract: A microchannel plate (MCP) tube comprises a photocathode on the MCP input electrode in addition to the conventional semitransparent cathode on the input window of the tube. The second cathode results in additional light being converted into photoelectrons. It also causes secondary emissions of the photoelectrons already generated at the tube window. These phenomena result in higher gain and signal-to-noise ratios for the tube. The second photocathode can employ a coating which is unstable in air to chemically combine with ions traveling in the backstream direction which would otherwise damage the cathode on the tube input window. Its construction can also be such as to function effectively as a trap or "getter" for neutral particles traveling back towards the input window.