Crystal Growth and Structural, Optical, and Visible Fluorescence Traits of Dy3+-doped SrGdGa3O7 Crystal

초록

Dy3+-doped SrGdGa3O7 crystal was successfully grown through the Czochralski method and investigated in detail for its structural and optical features. Its crystallographic lattice parameters were optimized by Rietveld refinement based on XRD data. Polarized absorption spectra, polarized emission spectra, and fluorescence decay curves of Dy: SrGdGa3O7 crystal were analyzed. Absorption cross-sections at 452 nm corresponding to pi- and sigma-polarization were computed as 0.594x10(-21) and 0.555x10(-21) cm(2), respectively. Calculated effective J-O intensity parameters Omega(2), Omega(4), and Omega(6) were 5.495x10(-20), 1.476x10(-20), and 1.110x10(-20) cm(2), respectively. J-O analysis and emission spectra show that transition F-4(9/2)-> H-6(13/2) of Dy: SrGdGa3O7 crystal has the highest fluorescence branching ratio and fluorescence intensity under 452 nm excitation within the visible spectral region, the emission cross-sections of pi- and sigma-polarization were 1.84x10(-21) and 2.49x10(-21) cm(2) at the wavelength of 574 nm, respectively. The measured radiative lifetime and fluorescence decay time of the Dy3+: F-4(9/2) level were 0.768 and 0.531 ms with a quantum efficiency of 69.1%. All these results reveal that Dy3+: SrGdGa3O7 crystal is a promising material for yellow lasers pumped with blue laser diodes.

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