We investigate the epitaxial growth of the dilute nitride InAsN alloy onto InAs and GaAs substrates with nitrogen content up to 1%. We report photoluminescence (PL) emission within the 2–4 µm spectral region and show that InAsN grown onto GaAs exhibits no degradation of the PL intensity and linewidth compared with epitaxial layers grown on near lattice-matched InAs substrates. Also, nitrogen can induce a significant reduction in the thermal quenching of the PL emission, which we attribute to the reduction in non-radiative Auger-recombination.