  We demonstrate deterministic control over the photon-number distribution by
interfering two coherent beams within a disordered photonic lattice. By
sweeping a relative phase between two equal-amplitude coherent fields with
Poissonian statistics that excite adjacent sites in a lattice endowed with
disorder-immune chiral symmetry, we measure an output photon-number
distribution that changes periodically between super-thermal and sub-thermal
photon statistics upon ensemble averaging. Thus, the photon-bunching level is
controlled interferometrically at a fixed mean photon-number by gradually
activating the excitation symmetry of the chiral-mode pairs with structured
coherent illumination and without modifying the disorder level of the random
system itself.
