The Application of Frequency Response Techniques in Optics

THE THEORY OF FREQUENCY RESPONSE CALCULATIONS One of the principal advantages that have come from optical frequency response theory has been the possibility of evaluating the frequency response curves, and therefore the image quality, from the constructional data of the optical system. Since the methods have to be equally applicable to, say, extra-axial images in very wide-angle systems, it was necessary to reconsider critically the Fraunhofer diffraction formula on which they are based.