  We present a light field imaging system that captures multiple views of an
object with a single shot. The system is designed to maximize the total light
collection by accepting a larger solid angle of light than a conventional lens
with equivalent depth of field. This is achieved by populating a plane of
virtual objects using mirrors and fully utilizing the available field of view
and depth of field. Simulation results demonstrate that this design is capable
of single-shot tomography of objects of size $\mathcal{O}$(1 mm$^3$),
reconstructing the 3-dimensional (3D) distribution and features not accessible
from any single view angle in isolation. In particular, for atom clouds used in
atom interferometry experiments, the system can reconstruct 3D fringe patterns
with size $\mathcal{O}$(100 $\mu$m). We also demonstrate this system with a
3D-printed prototype. The prototype is used to take images of $\mathcal{O}$(1
mm$^{3}$) sized objects, and 3D reconstruction algorithms running on a
single-shot image successfully reconstruct $\mathcal{O}$(100 $\mu$m) internal
features. The prototype also shows that the system can be built with 3D
printing technology and hence can be deployed quickly and cost-effectively in
experiments with needs for enhanced light collection or 3D reconstruction.
Imaging of cold atom clouds in atom interferometry is a key application of this
new type of imaging device where enhanced light collection, high depth of
field, and 3D tomographic reconstruction can provide new handles to
characterize the atom clouds.
