Abstract
The modulation transfer function (MTF) of the proximity focusing biplanar lens and the sharp focusing electrostatic and electromagnetic lenses is derived and presented. It is shown that for a Maxwellian emission energy distribution, the MTF of the biplanar lens is MTF exp(−4π2∊/VsL2f2), where L is the screen to cathode separation in mm, f is the spatial frequency in lp/mm, Vs is the screen voltage, and ∊ is the voltage equivalent of the most probable emission energy. For a cosine distribution, the MTF of the biplanar lens is MTF = exp(−7π∊/VsL2f2). The MTF of sharp focusing image tube lenses is MTF = exp(−0.06π2∊2M2f2/Ec2), where Ec is the cathode field strength in volts per mm and M is the magnification. In general, the MTF of image tube lenses is MTF = exp[−(πρf)2], where ρ is the focusing error coefficient of a particular lens.
© 1977 Optical Society of America
Full Article | PDF ArticleMore Like This
Edward H. Eberhardt
Appl. Opt. 16(8) 2127-2133 (1977)
Illes P. Csorba
Appl. Opt. 18(14) 2440-2444 (1979)
Ling Ren, Feng Shi, Hui Guo, Honggang Wang, and Benkang Chang
Appl. Opt. 52(8) 1641-1645 (2013)