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Synthesis of Mg-based alloys with rare-earth element addition by means of mechanical alloying

Lesz Sabina, Hrapkowicz Bartłomiej, Gołombek Klaudiusz, Karolus Małgorzata, Janiak Patrycja

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 5

art. no. e137586

EN

Magnesium-based alloys are widely used in the construction, automotive, aviation and medical industries. There are many parameters that can be modified during their synthesis in order to obtain an alloy with the desired microstructure and advantageous properties. Modifications to the chemical composition and parameters of the synthesis process are of key importance. In this work, an Mg-based alloy with a rare-earth element addition was synthesized by means of mechanical alloying (MA). The aim of this work was to study the effect of milling times on the Mg-based alloy with a rare-earth addition on its structure and microhardness. A powder mixture of pure elements was milled in a SPEX 8000D high energy shaker ball mill under an argon atmosphere using a stainless steel container and balls. The sample was mechanically alloyed at the following milling times: 3, 5, 8 and 13 h, with 0.5 h interruptions. The microstructure and hardness of samples were investigated. The Mg-based powder alloy was examined by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and using a Vickers microhardness test. The results showed that microhardness of the sample milled for 13 h was higher than that of those with milling time of 3, 5 and 8 h.

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Tunable Q-switched ytterbium-doped fibre laser by using zinc oxide as saturable absorber

Shaharuddin R. A., Azzuhri S. A., Ismail M. A., Rashid F. A. A., Samion M. Z., Razak M. Z. A., Ahmad H.

Opto-Electronics Review

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2017

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Vol. 25, No. 1

10--14

EN

This paper demonstrates the use of a zinc oxide (ZnO) thin film in a 1-μm ring laser cavity as a saturable absorber to successfully generate Q-switching pulses. The tunability of the laser pulses is achieved by integrating a tunable bandpass filter (TBPF) in an ytterbium-doped laser cavity that results in 9.4 nm of tuning range, which wavelength is from 1040.70 nm to 1050.1 nm. The peak energy in the pulse which is 1.47 nJ was measured together with a minimum pulse width of 2.4 μm. In addition, the repetition rate increases from 25.77 to 45.94 kHz as the pump power level being increased from 103.1 to 175.1 mW. The results obtained in this experiment demonstrated consistent results and stable throughout the experiment. Therefore, ZnO thin film is considered as a good candidate in 1-µm pulsed laser applications.

3

Novel constructions of optical fibers doped with rare – earth ions

Dorosz J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2014

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Vol. 62, nr 4

619--626

EN

In the paper the research on rare-earth doped and co-doped optical fibre conducted in the Laboratory of Optical Fiber Technology at the Bialystok University of Technology is presented. Novel active fibre constructions like multicore, helical-core and side detecting ribbon/core optical fibers were developed with a targeted focus into application. First construction i.e. multicore RE doped optical fibers enable supermode generation due to phase - locking of laser radiation achieved in a consequence of exchanging radiation between the cores during the laser action. In the paper a far - field pattern of 19 - core optical fiber-doped with Yb3+ ions, registered in the MOFPA system, showed centrally located peak of relatively high radiation intensity together with smaller side-lobes. Another new construction presented here is helical-core optical fibers with the helix pitch from several mm and the off-set ranging from 10 μm to 200 μm. The properties of helical-core optical fiber co-doped with Nd3+/Yb3+ were also discussed. In the field of sensor applications novel construction of a sidedetecting luminescent optical fiber for an UV sensor application has been presented. The developed optical fiber with an active core/ribbon, made of phosphate glass doped with 0.5 mol% Tb3+ ions, was used as a UV sensing element.

4

Fosforanowe włókno fotoniczne o powiększonym rdzeniu domieszkowanym jonami Yb3+ do zastosowań laserowych

Franczyk M., Stępień R., Pysz D., Kujawa I., Buczyński R.

Materiały Elektroniczne

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2013

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T. 41, nr 3

3--8

PL

W publikacji przedstawiono prace wykonane w Instytucie Technologii Materiałów Elektronicznych dotyczące wytworzenia światłowodu fotonicznego wykonanego ze szkła fosforanowego z przeznaczeniem do konstrukcji lasera włóknowego. Wykonane zostały wytopy szkieł domieszkowanych i niedomieszkowanych. Na podstawie przeprowadzonych pomiarów spektralnych przeprowadzono analizę własności absorpcyjnych i emisyjnych wytworzonego szkła domieszkowanego. Zweryfikowano parametry dopasowania szkieł domieszkowanego i niedomieszkowanego pod kątem właściwości reologicznych i współczynnika załamania. Wytworzone zostało włókno laserowe ze szkła fosforanowego o strukturze dwupłaszczowej (double-clad) w pełni wykonanej w technologii fotonicznej. Poprzez zastosowanie włókna o powiększonej średnicy rdzenia uzyskano znaczne zwiększenie absorpcji promieniowania pompy i skrócenie długości lasera. Ponadto stosując płaszcz powietrzny osiągnięto rekordową wartość apertury numerycznej falowodu pompy we włóknie typu double-clad ze szkła fosforanowego wynoszącą 0,91. Maksymalna moc generacji w laboratoryjnym układzie lasera we włóknie o długości 19 cm wyniosła 12,4 W przy sprawności różniczkowej 42,8 %.

EN

This paper presents the research work on a Yb3+ doped photonic crystal fiber laser with an extended mode area made of phosphate glass carried out at ITME. By increasing the mode area we obtained the laser with a higher power level and a shorter fiber length than before. The doped and undoped glass was manufactured and subsequently the measurements of optical and rheological properties were done. The analysis of both absorption and emission of the doped glass was performed. The fiber with the extended mode area was manufactured and its passive properties were examined. The numerical aperture of the pump waveguide was found to be very high and equaled 0.91, which is a record-breaking value for phosphate photonic structures and, at the same time, one of the highest values obtained for structures made of silica. We achieved laser generation from the 19 cm fiber with the maximum power of 12.4 W and the slope efficiency of 42.8 %.

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Post-recoil thermal annealing study of 177Lu, 169Yb, 175Yb, 166Ho and 153Sm in different organometallic compounds

Nassan L., Achkar B., Yassine T.

Nukleonika

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2011

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Vol. 56, No. 2

185-190

EN

Post-recoil thermal annealing study at different temperatures for different intervals of time of the recoiled isotopes 169Yb, 175Yb, 177Lu, 166Ho, and 153Sm resulting from the nuclear reactions 168Yb(n,gamma)169Yb, 174Yb(n,gamma)175Yb and 176Yb(n,gamma)177Yb → 177Lu, 165Ho(n,gamma)166Ho, 152Sm(n,gamma)153Sm, respectively in different organometallic compounds Yb(OCC(CH3)3CHCOC(CH3)3)3, Ho(OCC(CH3)3CHCOC(CH3)3)3, (C5H5)3Ho, and (C5H5)3Sm were carried out. The thermal annealing behaviors of 177Lu, 169Yb, 175Yb, 166Ho, and 153Sm were found to be different in the compounds under investigation. The differences in the patterns of the obtained isothermal curves were discussed. Depending on the post- -recoil thermal annealing manner the reactions taking place during thermal annealing were suggested.

6

Kryształy Yb:Sr3Y(B03)3 do budowy pompowanych diodowo laserów femtosekunkowych

Szyrski W., Malinowski M., Kiesielewski J., Świrkowicz M., Pawlak D., Kłos A., Diduszko R.

Materiały Elektroniczne

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2004

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T. 32, nr 1-4

49-63

PL

Monokryształy Yb:Sr3Y(BO3)3 (BOYS) domieszkowane iterbem mogą być stosowane jako materiał aktywny w laserach femtosekundowych. Szerokie pasmo absorpcji tego kryształu pozwala na pompowanie diodowe. Opracowano technologię przygotowania materiałów wyjściowych, zaprojektowano optymalny układ cieplny oraz przeprowadzono procesy krystalizacji metodą Czochralskiego. Określono optymalne warunki wzrostu i otrzymano czyste oraz domieszkowane iterbem monokryształy Yb:Sr3Y(BO3)3 Jakość kryształów została sprawdzona za pomocą dyfrakcji proszkowej oraz poprzez analizę chemiczną za pomocą metod ICP-AES. Kryształ domieszkowany iterbem został zbadany za pomocą następujących metod spektroskopowych: absorpcji, emisji oraz dynamiką fluorescencji dla różnych długości fal w pokojowej oraz niskiej temperaturze. W pracy porównano charakterystyki emisyjne, absorpcyjne oraz układy poziomów energetycznych jonu Yb3+ w kryształach BOYS i YAG.

EN

material for femtosecond lasers. The broad absorption bands give the possibility of with semiconductor laser diodes. In this work the technology of BOYS crystals is presented. The proper thermal | system was designed and prepared and the crystallization processes were carried out. Optimal growth conditions were found and the single crystals of pure Sr3Y(BO3)3 as well as the crystals doped with ytterbium ions were obtained by the Czochralski method. The quality of the crystals was checked by X-ray diffraction techniques and the chemical composition was checked by the ICP-AES. The crystal doped with ytterbium was characterised by the spectroscopic methods (absorption, emission, dinamics of fluorescence for different wavelengths at room and low temperatures).