Stark effects on the spectra of trivalent praseodymium ions in strontium fluorapatite laser host

An optical characterization of the Stark components of the ¹D₂ and ³W₄ manifolds has been performed using the fluorescence spectra for the ¹D₂→³H₄ transition of Pr³⁺ in Sr₅(PO₄)₃F laser host at 10 K. The temperature dependencies of the spectral width, position, and shift of the sharp, intense inter-Stark transition of the 623.6 (X₂→Y₅) nm line within the ¹D₂→³H₄ inter-manifold transition have been also investigated. The linewidth of this transition was found to increase with increasing crystal temperature. Also, the 623.6 nm line was found to shift toward the longer wavelength (redshift) as temperature was increased. The experimental results of the temperature dependent width and shift of this line are explained in light of the Debye model, which invokes phonon-ion interaction in crystalline solids.