S. Damodaraiah

Impact of Bi2O3 on structural properties and lasing effects in Nd3 + doped bismuth phosphate glasses at 1.053 μm emission

Influence of addition of bismuth oxide (Bi2O3) on structural and optical properties of 0.5Nd3+doped different phosphate glasses prepared by melt quenching technique were reported. The structural properties were analysed by FT-IR and 31P MAS NMR techniques. 31P NMR results showed that, with the variation of Bi2O3 concentration in the prepared phosphate glass matrices there was no significant change in the structure. The optical properties have been analysed using Judd-Ofelt (J-O) theory. From absorption spectra, three phenomenological J-O intensity parameters (Ω2, Ω4, Ω6) have been calculated and these parameters were used to estimate the radiative properties. The J-O intensity parameters increased with increase in the concentration of Bi2O3, which confirmed the higher covalency, asymmetry and rigidity. The branching ratios (β) and emission cross-sections (σ) were calculated from the emission spectra of Nd3+ doped bismuth phosphate (BiP) glasses. Among different glass matrices 15mol% of Bi2O3 glass matrix has higher β and σ values which are useful for the laser applications. The improved emission cross-section value with the addition of Bi2O3 content results low threshold and high gain applications. The decay curves of all these BiP glasses showed single exponential behaviour.

NIR emission at 1.53 μm in Er3+ doped lead free zinc phosphate glasses for potential broadband optical amplifiers

Er3+ doped zinc phosphate glasses with chemical compositions (60-x) NH4H2PO4 + 20ZnO+10BaF2+10NaF+xRE (where RE=Er2O3, x = 0.1, 0.5, 1.0, 1.5 and 2.0 mol%) have been prepared by melt quenching technique. Amorphous structure was ascertained by XRD analysis. The functional bands have been assigned and clearly elucidated by FT-IR spectral profiles for host glass sample. Judd-Ofelt (J-O) intensity parameters (Ωλ: λ=2, 4, 6) have been obtained from the spectral intensities of different absorption bands of Er3+ ion through optical absorption spectra. NIR photoluminescence spectra exhibited one emission band (4I15/2→4I13/2) of Er3+ ions. These glasses were suggested as suitable hosts for efficient lasing action in NIR region at 1534 nm for Er3+ ion.

Structural, optical and luminescence properties of Dy3+ doped bismuth phosphate glasses: Insights from 31P MAS NMR, absorption and photoluminescence

An investigation was carried out to observe structural and optical properties of 0.5 mol% Dy3+ doped different compositions of bismuth phosphate glasses (5, 10, 15 and 20 mol% Bi2O3). The structural characterization was accomplished by X-ray diffraction (XRD), 31P magic angle spin nuclear magnetic resonance (MAS NMR) spectroscopy. The optical properties were studied using absorption and photo luminescence (PL) spectroscopy. Judd-Ofelt intensity parameters Ωλ (λ=2, 4 and 6) were evaluated from absorption spectra. From photoluminescence spectra, experimental branching ratios (βexp) and stimulated emission cross-sections (σP) were calculated. The decay profiles for 4F9/2 level were recorded and were fit exponential. The obtained results show the prepared Dy3+ doped bismuth phosphate glasses might be useful as good optical material for yellow emission.An investigation was carried out to observe structural and optical properties of 0.5 mol% Dy3+ doped different compositions of bismuth phosphate glasses (5, 10, 15 and 20 mol% Bi2O3). The structural characterization was accomplished by X-ray diffraction (XRD), 31P magic angle spin nuclear magnetic resonance (MAS NMR) spectroscopy. The optical properties were studied using absorption and photo luminescence (PL) spectroscopy. Judd-Ofelt intensity parameters Ωλ (λ=2, 4 and 6) were evaluated from absorption spectra. From photoluminescence spectra, experimental branching ratios (βexp) and stimulated emission cross-sections (σP) were calculated. The decay profiles for 4F9/2 level were recorded and were fit exponential. The obtained results show the prepared Dy3+ doped bismuth phosphate glasses might be useful as good optical material for yellow emission.