  Differential cross sections of nuclear reactions often exhibit characteristic
oscillations in the angular distribution originated from an interference of two
indistinguishable processes. Here we propose a novel method to visualize
origins of such oscillations. This is achieved by taking Fourier transform of
scattering amplitudes, following the idea in wave optics. We apply this method
to elastic scattering of $^{16}$O+$^{16}$O and $^{18}$O+$^{18}$O at energies
above the Coulomb barrier. The former system shows strong oscillations in the
angular distribution due to the nearside-farside interferences, while the
oscillations are largely suppressed in the latter system due to a stronger
absorption. We show that the image of the former and the latter systems
corresponds to a double-slit and a single-slit problems in quantum mechanics,
respectively.
