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ABSTRACT: The properties of IR emission centers are investigated in Bi-doped Mg-Al-silicate glasses having moderate melting temperatures
to be fabricated by routine melting in alumina crucibles. The quadratic concentration dependence of absorption in the visible
range indicates that the considered optical centers can be Bi2 dimers forming in a balanced chemical reaction in the glass melt. Their formation enthalpy is evaluated from their concentration
variations with the synthesis temperature. The high (up to 85% at low concentrations) luminescence quantum yield and wide
emission spectrum makes this glass a promising material for tunable lasers.
Laser Physics 05/2012; 19(5):1105-1111. · 3.61 Impact Factor
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ABSTRACT: The activation of color centers in the bismuth aluminum-boron-phosphate glass by high-intensity femtosecond laser radiation
is experimentally studied. The dynamics of the laser-induced emitting centers in the bulk of sample is characterized. The
photoactivation of bismuth glasses is possibly related to the recharging of structural precursors, which serve as effective
electron traps and whose possible configuration is discusses. The effect of the femtosecond irradiation involves the initiation
of the nonlinear ionization of the glass matrix and the generation of plasma with the concentration of carriers that is sufficiently
high to provide almost complete recharging of precursors over several laser pulses.
Laser Physics 04/2012; 21(9):1585-1592. · 3.61 Impact Factor
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ABSTRACT: A new Bi-doped Mg–Al–silicate glass is suggested and investigated. It can be fabricated by moderate-temperature routine technology.
The characteristic relaxation time of 300–800μs in combination with the high quantum yield (up to85%) and wide excitation
spectrum makes this glass a promising laser material. The obtained quadratic dependence of the visible absorption intensity
is an argument in favor of the hypothesis that the absorption and infrared luminescence in Bi-doped glasses are caused by
Bi2 dimers.
Applied Physics B 04/2012; 95(4):801-805. · 2.19 Impact Factor
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ABSTRACT: The experimental study of the color centers activation in Bi-doped boro-alumino-phosphate glass by means a femtosecond laser irradiation was performed. The data of formation rate of laser-induced absorption centers in the glass bulk are presented. As a probable mechanism of bismuth glasses photoactivation a process of structural precursors recharging is proposed. This laser microfabrication technique opens up opportunities for active photonic crystals manufacturing.
Physics Procedia 01/2011; 12:156.
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ABSTRACT: This paper examines the synthesis conditions which influence the optical properties of the glass. For the experiments, 12% mol. MgO + 30% mol. AI<sub>2</sub>O<sub>3</sub> + 57%mol SiO<sub>2</sub> glass composition is chosen with additional Bi<sub>2</sub>O<sub>3</sub> doping. This composition corresponds to ternary euthectic point with melting temperature 1350degC. The samples (~50g each) were sintered for 4 hours starting from reagent-grade oxide powders in alumina crucibles in air. After the synthesis the crucibles were extracted from the oven and cooled in air. The resulting scatter- and inclusions-free pink-colored glass was annealed starting from 700degC. 2-mm thick polished plates were fabricated of all the synthesized glasses.
Lasers and Electro-Optics 2009 and the European Quantum Electronics Conference. CLEO Europe - EQEC 2009. European Conference on; 07/2009
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ABSTRACT: A study of Yb:GdCOB under diode-bar pumping has been performed and the results are compared, experimentally and theoretically,
with Yb:KGW in the same cavity. An output power of 7.3 W and a slope efficiency of 57.4% were obtained. Self-frequency-doubling
experiments are also discussed.
Laser Physics 08/2007; 17(10):1204-1208. · 3.61 Impact Factor
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ABSTRACT: Summary form only given. The aim of the present work was to compare the performance of Yb:GdCOB and Yb:KGW under end-pumping by a non-fiber-coupled diode-bar.
Lasers and Electro-Optics, 2007 and the International Quantum Electronics Conference. CLEOE-IQEC 2007. European Conference on; 07/2007
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ABSTRACT: A new Bi-doped boro-alumino-phosphate glass (BAP) composition was developed. Absorption and emission spectra and luminescence
decay kinetics were investigated. The emission spectrum consists of two wide bands in the visible (0.6–0.8μm) and near-infrared
(∼1.0–1.5μm) ranges. The luminescence decay curve investigation has revealed a complicated behavior dependent on both excitation
and registration wavelengths. In contrast to earlier investigated Bi-doped glasses, Bi:BAP has good technological properties
and can be easily scaled. This makes the developed glass composition interesting for broadband tunable (∼1.0–1.5μm) lasers
and amplifiers.
Applied Physics B 02/2007; 87(1):135-137. · 2.19 Impact Factor
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ABSTRACT: The paper presents the comparative tests of a number of passive Q-switchers in a continuously diode-pumped erbium glass (λ=1.54 nm) laser. The passive Q-switchers were: Co<sup>2+</sup>-doped and Cr<sup>2+</sup>- doped zinc selenide (ZnSe) and Co<sup>2+</sup>-doped spinel (MgAl<sub>2</sub>O<sub>4</sub>) crystals. Q-switched pulses with duration ranging from 16 to 980 ns and repetition rate ranging from 0.1 to 30 kHz were obtained.
Advanced Optoelectronics and Lasers, 2005. Proceedings of CAOL 2005. Second International Conference on; 10/2005
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ABSTRACT: We present the investigation of longitudinally pumped microchip Yb-Er lasers based on new crystalline medium GdCa<sub>4</sub>O(BO<sub>3</sub>)<sub>3</sub>. The main potential advantage of these crystals over Er-Yb glasses is the higher thermal conductivity, which may lead to higher thermal damage threshold. The advantage of GdCa<sub>4</sub>O(BO<sub>3</sub>)<sub>3</sub> (GdCOB) over YCOB is its lower melting point are discussed.
Lasers and Electro-Optics Europe, 2005. CLEO/Europe. 2005 Conference on; 07/2005
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ABSTRACT: We report, for the first time to our knowledge, efficient passive Q-switching of the 1.54-μm laser transition in an Er–Yb-doped crystalline medium. The laser configuration is a compact microchip design that is suitable for a range of practical applications such as range finding and lidar. The slope efficiency of 11.6%, pulse duration of 5–6 ns and average output power of 88 mW are all comparable with standard Er–Yb:glass lasers.
Applied Physics B 06/2005; 81(1):49-52. · 2.19 Impact Factor
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ABSTRACT: We present for the first time 1.5-m laser emission in Yb–Er:GdCa4O(BO3)3 (GdCOB). The crystals were grown by the Czochralski method from platinum crucibles. Spectroscopic and laser tests of the crystals are described. A continuous-wave output power of 80mW was achieved in a monolithic microchip cavity under laser-diode pumping.
Applied Physics B 08/2004; 79(5):577-581. · 2.19 Impact Factor
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ABSTRACT: The 3-level nature of erbium ions lasing at 1.5 μm requires minimizing the volume of the active medium in order to reduce the lasing threshold. Efficient optical pumping of small volumes of bulk laser glass needs high pump extinction in the laser medium, i.e. as high Yb concentration as technologically possible. The main problem in this case is to avoid crystallization of the concentrated glasses. Our search for a stable concentrated glass composition resulted in developing a technologically producible Yb-Er glass containing 4.2×10<sup>21</sup> cm<sup>-3</sup> of ytterbium ions about twice as usually used in commercially available laser glasses. This feature makes efficient pumping of small (2-3 mm) laser rods easily possible without bothering about the exact pump wavelength (in the range from ∼850 to 1000 nm) and without LD array thermal stabilization. A secondary goal was the development of a new Yb-Er activated laser glass that should combine good laser efficiency and sufficiently higher thermo-mechanical properties them the available ones. We have investigated another cobalt-doped material for passive Q-switching of erbium glass lasers: magnesium-aluminum spinel MgAl<sub>2</sub>O<sub>4</sub> grown by a number of methods: Czochralski, flux and Verneuil.
Laser and Fiber-Optical Networks Modeling, 2003. Proceedings of LFNM 2003. 5th International Workshop on; 10/2003
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ABSTRACT: A new strong erbium laser glass (SELG) based on a boro-alumo-phosphate composition is reported. We discuss the synthesis and
chemical properties together with spectroscopic and thermo-mechanical data. The new glass composition shows excellent laser
performance and withstands high-average power pump radiation. We present laser results at 1.54μm from flashlamp and laser
pumping. In tests with laser-diode pumped Q-switched Er-Yb microchip lasers, we have achieved up to 150mW of average output
power and generated 1.2kW in peak power. Co2+:MgAl2O4 was here used as the saturable absorber.
Applied Physics B 06/2002; 75(1):41-46. · 2.19 Impact Factor
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ABSTRACT: Energy transfer and spectroscopic properties at high temperatures have been investigated in Er,Yb:YAG crystals. It is shown that at elevated temperatures around 600–800 °C these characteristics become similar to those in the efficient 1.5 μm laser medium – Er,Yb-doped phosphate glasses.
Optics Communications.
