Emission cross sections and spectroscopy of Ho3+ laser channels in KGd(WO4)2 single crystal
| Autor: | Pujol, María Cinta, Massons, Jaume, Aguiló, Magdalena, Díaz, Francisco, Rico, Mauricio, Zaldo, Carlos |
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| Jazyk: | angličtina |
| Rok vydání: | 2002 |
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| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | The spectroscopic properties of Ho3+ laser channels in KGd(WO4)2 crystals have been investigated using optical absorption, photoluminescence, and lifetime measurements. The radiative lifetimes of Ho3+ have been calculated through a Judd-Ofelt (JO) formalism using 300-K optical absorption results. The JO parameters obtained were Ω2=15.35×10-20 cm2, Ω 4=3.79×10-20 cm2, Ω6 =1.69×10-20 cm2. The 7-300-K lifetimes obtained in diluted (8·1018 cm-3) KGW:0.1% Ho samples are: τ(5F3)=0.9 μs, τ( 5S2)=19-3.6 μs, and τ(5F5 )=1.1 μs. For Ho concentrations below 1.5×1020 cm-3, multiphonon emission is the main source of non radiative losses, and the temperature independent multiphonon probability in KGW is found to follow the energy gap law τph -1(0)=βexp(-αΔE), where β=1.4×10-7 s-1, and α=1.4×103 cm. Above this holmium concentration, energy transfer between Ho impurities also contributes to the losses. The spectral distributions of the Ho3+ emission cross section σEM for several laser channels are calculated in σ- and π-polarized configurations. The peak a σEM values achieved for transitions to the 5I8 level are ≈2×10-20 cm2 in the σ-polarized configuration, and three main lasing peaks at 2.02, 2.05, and 2.07 μm are envisaged inside the 5I7→5I8 channel. This work was supported by Comisión Interministerial de Ciencia y Tecnología under Projects MAT99-1077 and 2FD97-0912. |
| Databáze: | OpenAIRE |
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