This manuscript reports on the interaction between 2 F 5/2 â †' 2 F 7/2 radiative transition from Yb 3+ ions and localized surface plasmon resonance (from gold/silver nanoparticles) in a tungsten-tellurite glass. Such an interaction, similar to the down-conversion process, results in the Yb 3+ emission in the near-infrared region via resonant and non-resonant energy transfers. We associated such effects with the dynamic coupling described by the variations generated by the Hamiltonian H DC in either the oscillator strength, or the local crystal field, i.e. the line shape changes in the emission band. Here, the Yb 3+ ions emission is achieved through plasmon-photon coupling, observable as an enhancement or quenching in the luminescence spectra. Metallic nanoparticles have light-collecting capability in the visible spectrum and can accumulate almost all the photon energy on a nanoscale, which enable the excitation and emission of the Yb 3+ ions in the near-infrared region. This plasmon-photon conversion was evaluated from the cavityâ €™ s quality factor (Q) and the coupling (g) between the nanoparticles and the Yb 3+ ions. We have found samples of low-quality cavities and strong coupling between the nanoparticles and the Yb 3+ ions. Our research can be extended towards the understanding of new plasmon-photon converters obtained from interactions between rare-earth ions and localized surface plasmon resonance.