New half-film method for measuring Al2O3 film MTF of 3rd generation image intensifier

In 3rd generation image intensifier, Al<sub>2</sub>O<sub>3</sub> film on the input of MCP is a serious influence factor on device MTF due to its electron scattering process. There are no reportes about how to measure the MTF of Al<sub>2</sub>O<sub>3</sub> film. In this paper a new Half-film comparssion test method is creatively established for determing the film MTF, which overcomes the difficulty of measuring super thin film less than a few nm. In this way, the MTF curves of 10nm Al<sub>2</sub>O<sub>3</sub> film can be accurately obtained. The measurement results show that 10nm Al<sub>2</sub>O<sub>3</sub> film obviously decay the MTF performance of the 3rd generation image intensifier and take an important role in the improvement work of 3rd generation image intensifier MTF and resolution performances.