  Large quantum photonic systems hold promise for surpassing classical
computational limits, yet their state preparation remains a challenge. We
propose an alternative approach to study multiparticle dynamics by mapping the
excitation mode of these systems to physical properties of the Laguerre-Gauss
modes. We construct coherent states establishing a direct link between
excitation number dynamics and the evolution of the Laguerre-Gauss mode. This
highlights the photon transverse spatial degree of freedom as a versatile
platform for testing fundamental aspects of quantum multiparticle systems.
