Stimulated Emission Cross Research Articles

Spectroscopic Properties of Er3+ Doped in Zinc Lithium Calcium Potassiumniobate Phosphate Glasses

Abstract: Zinc lithium calcium potassiumniobate phosphate glasses containing Er3+ in (45-x): P2O5:10ZnO:10Li2O:10CaO:10K2O:15Nb2O5:xEr2O3. (where x=1, 1.5,2 mol %) have been prepared by melt-quenching method. The amorphous nature of the glasses was confirmed by x-ray diffraction studies. Optical absorption, Excitation, and fluorescence spectra were recorded at room temperature for all glass samples. Judd-Ofelt intensity parameters Ωλ (λ=2, 4, 6) are evaluated from the intensities of various absorption bands of optical absorption spectra. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross– section of various emission lines have been evaluated.

Spectral and FTIR Analysis of Tm3+ Doped in Zinc Lithium Tungsten Sodalime Borotellurite Glasses

Abstract: Glass sample of Zinc Lithium Tungsten Sodalime Borotellurite: (35-x) TeO2:10ZnO:10Li2O:10WO3:10CaO:10Na2O:15B2O3:xTm2O3. (where x=1,1.5 and 2 mol%) have been prepared by meltquenching technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction. Optical absorption ,fluorescence and FTIR spectra were recorded at room temperature for all glass samples. Judd-Ofelt intensity parameters Ωλ (λ=2, 4 and 6) are evaluated from the intensities of various absorption bands of optical absorption spectra. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross– section of various emission lines have been evaluated

Dy3+ doped B2O3 – Li2O – CaO – CaF2 glass for efficient white light emitting sources

In this present work, Dy3+ doped B2O3 – Li2O – CaO – CaF2 (BLCFDy) glasses with variable concentrations of alkaline and alkaline earth oxide elements are prepared. The X – Ray diffraction technique has been carried out to verify the non crystallinity of BLCFDy glasses. The Fourier Transform Infrared (FT-IR) study reveals that, the structural properties of glasses exhibiting stretching and vibrational groups of various borate groups. The Optical absorption spectroscopy in Ultraviolet – Visible and Near Infrared regions provides glasses have strong absorption in NIR region for excitations 6H15/2 → 6F7/2 (895nm), 6F9/2 (1084nm), 6H9/2 (1267nm) and 6H11/2 (1686nm) states. The Optical band gap measurements prove existence of non-bridging oxygens (NBOs), localization of charges and donor centres in prepared glass samples. Judd–Ofelt hypothesis and intensity parameters (Ω2,Ω4 andΩ6) predicts higher degree of symmetry in covalency and encompassing environment of Dy3+ ions with constituent ligand elements. The radiative properties of glass samples like radiative transition probability (AR), branching ratios both calculated and experimental (βcal & βrad), peak band width (∆λp), stimulated emission cross – section and gain band width (σse x ∆λp) predicts that prepared glasses are good host of lasing materials and optical gain medium. The Photoluminescence emission spectra exhibits two principle strong emissions at 484nm (Blue), 575nm (Yellow) and observable emission at 664nm (Red) owing to de-excitation from 4F9/2 to respective 6H15/2, 6H13/2 and 6H11/2 states. CIE - 1931 chromaticity coordinates (x, y) and CCT values are calculated from photoluminescence emission spectra were found to be within the white light region of the CIE. For the glasses BLCFDy2 and BLCFDy3 colour coordinates (x, y) are (0.34, 0.37), (0.34, 0.38) respectively. The corresponding CCT values are 5223K and 5237K. Thus, BLCFDy2 and BLCFDy3 are the potential candidates for fabrication of white light emitting diodes (W – LEDs) also as laser host materials.

Synergistic effects of Nd3+ and Ag nanoparticles doping on spectroscopic attributes of phosphate glass

Abstract Efficient, inexpensive and eye−safe new host glass as up−conversion (UC) emission solid−state laser media became demanding. Nanoparticles (NPs) of various noble metals have been inserted into the phosphate−based amorphous host matrix to enhance the rare-earth ions (REIs) stimulated emission cross−section. Furthermore, only a few reports exist on the combined influences of neodymium ions (Nd3+) and pure silver (Ag) NPs on the structural and optical response of magnesium zinc sulfophosphate (MZSP) glasses. In this view, a series of MZSP glasses were doped by Nd3+ ions and pure Ag NPs (at different concentrations) to improve their structural and optical properties. Such melt−quench synthesized glasses were characterized at room temperature using diverse analytical measurement tools. The XRD pattern of as−quenched samples approved their amorphous nature. The FTIR and Raman spectra of glasses revealed the presence of characteristic bonding vibrations of different functional groups. The TEM images showed the existence of spherical Ag NPs (mean size of 8.34 nm) in the host glass matrix. The surface plasmon resonance (SPR) band of Ag NPs was detected around 451 nm. The UV–Vis–NIR absorption and PL emission spectra of glasses were utilized to evaluate the Judd−Ofelt (JO) intensity parameters ( Ω 2 , Ω 4 and Ω 6 ) and radiative properties. The observed fluctuation in the Ω 2 values with the increase in Ag NPs contents was attributed to the dynamic change of ligands symmetry around Nd3+ inside the glass network. Variations in the Ω 4 and Ω 6 values with the increase in Ag NPs contents indicated a considerable reduction in the glass rigidity. The PL spectra of glasses exhibited a prominent band around 576–584 nm corresponding to the 2G7/2 +4G5/2 → 4I9/2 transition in Nd3+. Glass prepared with 0.5 mol% of Ag NPs disclosed the highest PL enhancement (≈19 times) and largest emission cross−section (≈4.35 × 10−24 cm2) which was ascribed to the synergism between Ag NPs SPR mediated strong local field effect (LFE) and the subsequent energy transfer to Nd3+ appeared in the proximity of NPs. It was concluded that the proposed glass composition can lead to the development of UC solid−state laser compared to many other reported glass system.

A study of low threshold and high gain Nd3+ ions doped SiO2-B2O3-Na2CO3-NaF-CaF2 glasses for NIR laser applications

Fluoroborosilicate glasses of composition 35SiO2-25B2O3-10Na2CO3-15NaF-15CaF2-xNd2O3 (where x = 0.1, 0.5. 1.0, 2.0 mol%) were prepared by melt quenching technique and various physical properties have been calculated. From the absorption spectra J-O Intensity parameters Ωλ (λ = 2, 4, 6) and radiative properties are evaluated by using J-O theory. The high values of Ω2 = 4.213 × 10−20 cm2, Ω4 = 5.345 × 10−20 cm2, Ω6 = 5.526 × 10−20 cm2 suggest that among the prepared glasses 0.5 mol% Nd glass is more asymmetric, more covalent and rigid in nature. The emission spectra were recorded with 808 nm laser as excitation source. The strong NIR emissions were observed at 876 nm, 1056 nm, 1328 nm corresponding to the transitions 4F3/2 → 4I9/2, 4F3/2 → 4I11/2, 4F3/2 → 4I13/2 respectively. Stimulated emission cross -section (σemi) and Gain bandwidth (σemi × Δλeff) were calculated. For 0.5 mol% Nd these values are found to be 3.30 × 10−20 cm2, 11 × 10−26 cm2. From the decay curve analysis the lifetime values for 4F3/2 level have been determined and these values are decreased with increase in Nd3+ ions concentration. These results may suggest that the prepared SBNCNd05 (Nd = 0.5 mol%) glass could be useful for 1056 nm laser applications.

Stimulated Emission and Rb Spin-Exchange Cross Section

Stimulated Emission and Rb Spin-Exchange Cross Section