Fourier Transform, Optical Computing, Free Space Optics.
will denote by a curly F with index d the discrete Fourier transform in dimension d. If A is an array (or, to use a slightly more precise word, a real or complex tensor) of shape (N₁, N₂, …), where N₁, N₂, … are positive integers, then the Fourier transform of A​ is an array (or tensor) with the