  Since the diffraction behavior of a light field is fully determined by its
spatial wavefunction, i.e., its spatial complex amplitude (SCA), full
characterization of spatial wavefunction, plays a vital role in modern optics
from both the fundamental and applied aspects. In this work, we present a novel
complex-amplitude profiler based on spatial Stokes tomography with the
capability to fully determine the SCA of a light field in a single shot with
high precision and resolution. The SCA slice observed at any propagation plane
provides complete information about the light field, thus allowing us to
further retrieve the complete beam structure in 3 dimensions space, as well as
the exact modal constitution in terms of spatial degrees of freedom. The
principle demonstrated here provides an important advancement for the full
characterization of light beams with a broad spectrum of potential applications
in various areas of optics, especially for the growing field of structured
light.
