The effect of different conditions of illumination and the spectral sensitivity of the detector on the performance of proximity-focused image tube has been evaluated in terms of the polychromatic modulation transfer function. The physical efficiencies of sources commonly used in the infrared image conversion system have been compared for a Corning glass 2540 glass filter and a GaAs filter having antireflection coatings on both sides.
O. P. Nijhawan, P. K. Datta, and C. R. Sharma, "MTF of Proximity-Focused Image Tube in Polychromatic Light," Appl. Opt. 14, 509-512 (1975)