Excitation of Anti-Stokes Luminescence in Y 2 O 2 S:Er Ceramics with the Participation of the Erbium 4 I 13/2 Metastable State

— Emission and visible photoluminescence excitation spectra of Y 2 O 2 S:Er (1 at %) ceramics have been studied under different optical pumping conditions. The results demonstrate that visible anti-Stokes luminescence of the erbium-doped material has higher intensity in the case of pumping of the 4 I 13/2 metastable state of the dopant. Resonance IR photon wavelengths have been determined for two-photon excitation of visible emission in Y 2 O 2 S:Er. A method has been developed for the optical excitation of metastable states (excited-state excitation (ESE)) in anti-Stokes luminescence, which allows the nature of the corresponding electronic transitions in emission centers to be identified.