  The optical interference constitutes a paramount resource in modern physics.
At the scale of individual atoms and photons, it is a diverse concept that
causes different coherent phenomena. We present the experimental
characterization of both coherent and statistical properties of light emitted
from ensembles of trapped ions increasing with a number of contributing
phase-incoherent independent atomic particles ranging from a single to up to
several hundreds. It conclusively demonstrates how super-Poissonian quantum
statistics non-trivially arises purely from the finite number of
indistinguishable single-photon emitters in the limit of a single detection
mode. The achieved new optical emission regime in which these independent atoms
contribute coherently to the super-Poissonian statistics provides a new
perspective on the emergence of optical coherence at the atomic scale and
constitutes a unique toolbox for its generation and control at the most
microscopic level.
