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 melt-quenching 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 ?? (?=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
Transparent glass–ceramic as host materials for active optical ions have attracted great interest recently due to their potential application in optical devices such as frequency-conversion materials, lasers and optical fiber amplifiers [1-5]. Among these hosts, the borotellutite system is attractive due to its superior physical, structural and optical properties [6, 7]. ZnO is a wide band gap semiconductor and has received increasing research interest. It is an important multifunctional material due to its specific chemical, surface and micro structural properties . Tellurite glasses have a low glass transition temperature, low melting temperature and high gain density.
The high gain density in tellurite glasses is due to high solubility of rare earth ions in tellurite network [9-14]. Recently, glass-ceramics containing dysprosium oxides have been found in applications for several different purposes. Tm3+ doped glasses have attracted much interest due to their important optical properties used in lasers, optical amplifiers, network formers, photonic devices and as infrared sensors [15-18].
The present work reports on the preparation and characterization of rare earth doped heavy metal oxide (HMO) glass systems for lasing materials. I have studied on the absorption, emission and FTIR properties of Tm3+ doped zinc lithium tungsten sodalime borotellurite glasses.
The intensities of the transitions for the rare earth ions have been estimated successfully using the Judd-Ofelt theory, The laser parameters such as radiative probabilities(A),branching ratio (β), radiative life time(τR) and stimulated emission cross section(σp) are evaluated using J.O.intensity parameters( Ωλ, λ=2,4 and 6).
II. EXPERIMENTAL TECHNIQUES
A. Preparation of Glasses
The following Tm3+doped borotellurite glass samples (35-x) TeO2:10ZnO:10Li2O:10WO3:10CaO:10Na2O:15B2O3:xTm2O3. (where x=1,1.5 and 2 mol%) have been prepared by melt-quenching method. Analytical reagent grade chemical used in the present study consist of TeO2, ZnO, Li2O, WO3, CaO, Na2O3,B2O3 and Tm2O3.
They were thoroughly mixed by using an agate pestle mortar. then melted at 9800C by an electrical muffle furnace for 2h., After complete melting, the melts were quickly poured in to a preheated stainless steel mould and annealed at temperature of 2500C for 2h to remove thermal strains and stresses. Every time fine powder of cerium oxide was used for polishing the samples. The glass samples so prepared were of good optical quality and were transparent. The chemical compositions of the glasses with the name of samples are summarized in Table 1.
In the present study, the glass samples of composition (35-x)TeO2:10ZnO:10Li2O:10WO3:10CaO:10Na2O:15B2O3
:xTm2O3. (where x =1, 1.5 and 2mol %) have been prepared by melt-quenching method. The value of stimulated emission cross-section (?p) is found to be maximum for the transition (3F4?3H6) for glass ZLTSLBT (TM 01), suggesting that glass ZLTSLBT (TM 01) is better compared to the other two glass systems ZLTSLBT (TM 1.5) and ZLTSLBT (TM 02).
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