Pr3+-doped CeF3 crystals: Analysis of optical traits and fluorescence from Pr3+: 1D2 level for visible and near-infrared lasers

Abstract

In this work, four Pr3+ -doped CeF3 crystals with 0.2, 0.4, 0.6, and 0.8 at.% Pr3+ ion doping levels nominally in the melt have been successfully grown, and their absorption and emission spectra, including fluorescence decay times were analyzed. Especially, yellow and near-infrared (NIR) emissions originating from Pr3+: 1D2 level were explored in detail. In comparison, 0.2 at.% Pr3+-doped sample showed better spectral parameters in all studied crystals. In such a crystal, at 443 nm wavelength, the derived absorption cross-section (σabs) is 0.88 × 10-20 cm2 with full width at half maximum (FWHM) ∼ 10 nm in π polarization direction, whereas σabs is 1.32 × 10-20 cm2 with FWHM ∼ 6.7 nm in σ polarization direction at the same wavelength. Likewise, the calculated emission cross-section (σem) for 594 nm wavelength is 0.69 × 10-20 cm2 in π direction and 0.46 × 10-20 cm2 in σ direction. Also, acquired σem at 790, 755, 1014, and 1432 nm wavelengths is 6.15 × 10-21 cm2, 7.33 × 10-21 cm2, 7.66 × 10-21 cm2, and 6.56 × 10-21 cm2 individually. Here evaluated fluorescence decay time of 1D2 level is ∼ 200.6 μs. Obtained higher σabs, larger σem, and higher luminescence decay rates of 0.2 at.% Pr: CeF3 crystal specify its potential as a gain medium for orange and NIR lasers.