Abstract

The image quality and the resolving power of an optical device can be improved by improving its modulation-transfer-function (MTF). It is especially important for the devices which are designed for conditions of low illumination, such as a night vision. The case of infrared image converters and intensifiers with an inverting electron-optical system (EOS) and a micro-channel plate (MCP) as an amplifier is taken for consideration in this work. The electron amplification process in the channel is simulated by Monte Carlo methods. As a result, the energy and angular distributions are determined and used as initial conditions for calculation of the current density distribution in the channel image on the screen. The effect of the electrostatic field penetration into the channel on the current-density distribution and the MTF of the system is under investigation in this work. The effect of the length of the contact conducting layer on the field penetration and MTF is evaluated. It is also shown how the emission from the conducting layer affects the resolution. The optimal parameters of EOS which provide a flat image surface to coincide with the channel plate are defined. Position of the best focus in the electron beam, what provides the highest resolution, is determined. Finally, the total MTF of the imaging device is calculated.