Scaled optical Fourier transform: practical limitations

Abstract

The Optical Fourier Transform (OFT) is the most fundamental operation in analogue Optical Signal Processing (OSP). The Scaled Optical Fourier Transform (SOFT) is widely used as it provides a great deal of flexibility, which is invaluable in real implantations. In this paper we study some of the practical limits introduced by the use of an illuminating lens of finite aperture. We show, by deriving simple rules of thumb based on examining phase and intensity deviations, that the worst case diffraction errors can be avoided.