The Design Of A Laser Interferometer For Image Tube Resolution Measurements

The optical transfer function of an optical component such as a lens or image tube is of great importance because this one function, together with any scene entering the lens, can be used to predict the scene leaving the lens. The concept of the optical transfer function, which is the product of a phase transfer function and a modulation transfer function (MTF) has been well described in the literature (Ref. 1). The analogous situation in electronics is that of an arbitrary waveform entering a linear electronic black box. Armed only with the transfer function, the engineer can predict the output waveform in the following way: the input waveform is decomposed into its Fourier components, each component is multi-plied by the value of the transfer function at that frequency, and the result is summed over all frequencies. The transfer function changes the amplitude and shifts the phase of each Fourier component.