  Single and two-mode multiphoton states are the cornerstone of many quantum
technologies, e.g., metrology. In the optical regime these states are generally
obtained combining heralded single-photons with linear optics tools and
post-selection, leading to inherent low success probabilities. In a recent
paper, we design several protocols that harness the long-range atomic
interactions induced in waveguide QED to improve fidelities and protocols of
single-mode multiphoton emission. Here, we give full details of these
protocols, revisit them to simplify some of their requirements and also extend
them to generate two-mode multiphoton states, such as Yurke or NOON states.
