Polarization tuning the Stokes photoluminescence spectra of erbium doped KNbO₃ ceramics

The Stokes photoluminescence spectra with different poling conditions and different annealing temperature in the erbium doped potassium niobate ceramics was investigated. Poling effect showed that the polarization changed the peak intensity and the spectral shape. Erbium doped KNbO₃ ceramics were prepared by ceramic solid-state reaction synthesized method. The frequency shift of the peaks depended on the wavelength of the spectra after poling treatment demonstrated that the Stark splitting was produced by the dipole moment of erbium ions interacting with the internal local electric field due to polarization.