Tunable telephoto: governable Fourier spectrum anamorphic scaling

We discuss the Gaussian design of a device that controls the scale, in an anamorphic fashion, of Fraunhofer diffraction patterns. The device uses two pairs of varifocal cylindrical lenses. For spherical lenses, the optical powers can be predicted by using a previously known high-level solution. We emphasize the anamorphic capabilities, by considering the case My = 1/ Mx. The proposed device does not introduce vignetting, and it does not alter the axial location of the Fraunhofer diffraction patterns. Since the composing elements work at fixed inter-lens separation, the device does not require mechanical compensation