Czochralski Growth of Oxide Laser Crystals

1993 ◽  
Vol 329 ◽  
Author(s):  
Milan R. Koka
Keyword(s):  
Crystal Growth ◽  
Czochralski Growth ◽  
Solid State Lasers ◽  
Optically Pumped ◽  
Inorganic Oxides ◽  
Melting Temperatures ◽  
Individual Crystal ◽  
Large Size ◽  
Laser Crystals ◽  
Oxide Crystals

The most widely used active elements of optically pumped solid state lasers are crystals of inorganic oxides. Such oxide materials crystallasing in either garnet or corundum structures are prepared on industrial scale by the pulling technique known as Czochralski Crystal Growth. The description of the present state-of-the-art in Czochralski growth is described along with critical variables involved in growth of large size, high quality oxide crystals. The description of crystal growth of ruby, yttrium aluminum garnets, and titanium sapphire is presented. The effects of compositions, ambient atmospheres, crystal growth variables, and environmental conditions on individual crystal types are described. Suitability of the Czochralski technique for crystal growth of different oxides is discussed with emphasis on material properties such as phase diagram implication (congruency of melting), melting temperatures, crucible materials, effects of doping ions, and high temperature melt chemistry.

scholarly journals Czochralski growth of mixed cubic sesquioxide crystals in the ternary system Lu2O3–Sc2O3–Y2O3

2021 ◽  
Vol 77 (4) ◽  
Author(s):  
Christian Kränkel ◽  
Anastasia Uvarova ◽  
Émile Haurat ◽  
Lena Hülshoff ◽  
Mario Brützam ◽  
...  
Keyword(s):  
Ternary System ◽  
Czochralski Method ◽  
Optical Quality ◽  
Czochralski Growth ◽  
High Optical Quality ◽  
Melting Temperatures ◽  
Large Size ◽  
Host Materials ◽  
Thermal Investigations ◽  
First Time

Cubic rare-earth sesquioxide crystals are strongly demanded host materials for high power lasers, but due to their high melting points investigations on their thermodynamics and the growth of large-size crystals of high optical quality remain a challenge. Detailed thermal investigations of the ternary system Lu2O3–Sc2O3–Y2O3 revealing a large range of compositions with melting temperatures below 2200°C and a minimum of 2053°C for the composition (Sc0.45Y0.55)2O3 are presented. These reduced temperatures enable for the first time the growth of high optical quality mixed sesquioxide crystals with disordered structure by the conventional Czochralski method from iridium crucibles. An (Er0.07Sc0.50Y0.43)2O3 crystal is successfully grown and characterized with respect to its crystallographic properties as well as its composition, thermal conductivity and optical absorption in the 1 µm range.

scholarly journals Numerical Analysis of Difficulties of Growing Large-Size Bulk β-Ga2O3 Single Crystals with the Czochralski Method

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 25
Author(s):  
Xia Tang ◽  
Botao Liu ◽  
Yue Yu ◽  
Sheng Liu ◽  
Bing Gao
Keyword(s):  
Crystal Growth ◽  
Single Crystals ◽  
Czochralski Method ◽  
Liquid Interface ◽  
Spiral Growth ◽  
Growth Time ◽  
Large Size ◽  
Crystal Diameter ◽  
Solid Liquid Interface ◽  
Solid Liquid

The difficulties in growing large-size bulk β-Ga2O3 single crystals with the Czochralski method were numerically analyzed. The flow and temperature fields for crystals that were four and six inches in diameter were studied. When the crystal diameter is large and the crucible space becomes small, the flow field near the crystal edge becomes poorly controlled, which results in an unreasonable temperature field, which makes the interface velocity very sensitive to the phase boundary shape. The effect of seed rotation with increasing crystal diameter was also studied. With the increase in crystal diameter, the effect of seed rotation causes more uneven temperature distribution. The difficulty of growing large-size bulk β-Ga2O3 single crystals with the Czochralski method is caused by spiral growth. By using dynamic mesh technology to update the crystal growth interface, the calculation results show that the solid–liquid interface of the four-inch crystal is slightly convex and the center is slightly concave. With the increase of crystal growth time, the symmetry of cylindrical crystal will be broken, which will lead to spiral growth. The numerical results of the six-inch crystal show that the whole solid–liquid interface is concave and unstable, which is not conducive to crystal growth.

Bulk laser damage of large-size KDP crystals obtained at various crystal growth conditions

1994 ◽  
Author(s):  
Marina I. Kolybayeva ◽  
Igor M. Pritula ◽  
Viacheslav M. Puzikov ◽  
Vitaly I. Salo ◽  
Serge V. Garnov ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Growth Conditions ◽  
Laser Damage ◽  
Large Size ◽  
Kdp Crystals

Thermal effects of diode-end-pumped dual-wavelength solid-state lasers with coaxially arranged dual laser crystals

2021 ◽  
Author(s):  
Yizhe Zheng ◽  
Kai Zhong ◽  
Kefei Liu ◽  
Hongzhan Qiao ◽  
Xianzhong Zhang ◽  
...  
Keyword(s):  
Solid State ◽  
Thermal Effects ◽  
Dual Wavelength ◽  
Solid State Lasers ◽  
Laser Crystals ◽  
Dual Laser

Thermodynamic properties of melts of Bi—Eu system

2021 ◽  
Vol 2021 (2) ◽  
pp. 90-100
Author(s):  
V. S. Sudavtsova ◽  
◽  
V,A, Shevchuk ◽  
L. O. Romanova ◽  
M. I. Ivanov ◽  
...  
Keyword(s):  
Enthalpy Of Mixing ◽  
Enthalpies Of Formation ◽  
Thermochemical Properties ◽  
Melting Temperatures ◽  
Large Size ◽  
Intermediate Phases ◽  
Ideal Solutions ◽  
First Time ◽  
Enthalpy Data ◽  
The Eu

The thermochemical properties of alloys were determined for the first time by calorimetry Bi—Eu system at a temperature of 1200 K in the range of 0 ≤ xBi ≤ 0,2 and 0,77 ≤ xBi ≤ 1,0. It is established that the minimum value of the enthalpy of mixing is equal to –61,7 ± 0,5 kJ / mol at xBi = 0,5. = –184,7 ± 16,7 kJ / mol, = = –206,9 ± 21,8 kJ / mol. The activities of the components were calculated according to the model of an of the ideal associated solution (IAR), using the thermochemical properties of the melts of the Bі—Eu. system. It has been established that the activities of the components show large negative deviations from ideal solutions. To predict the enthalpies of formation of LnBi compounds, the available literature data on these parameters are analyzed and the most reliable ones are presented as a dependence on ∆fH = f(ZLn). It is established that the enthalpies of formation LnBi change smoothly and monotonically with the exception of Bi—Eu and Bi—Yb systems. This is due to the large size factors for the last two systems. To combine all the enthalpy data of Ln—Bi intermetallic formation of Ln—Bi systems depending on the sequence number Ln, we need similar values for the Eu—Bi compound. But at present they are not known, so based on the above, it was assumed that the value of the minimum enthalpy of mixing will be close to the enthalpy of formation of this compound. This hypothesis is confirmed by data on the enthalpies formation of phase YbBi and equiatomic melts of binary of Yb—Bi system. To confirm the thermodynamic data, we compare the known melting temperatures of the formed intermediate phases, known from the diagrams state Bi—Ln system. The obtained dependences correlate with ∆fH = f(ZLn ) і ∆V = f(ZLn). This means that the predictions of thermochemical properties accurately reflect the nature of the considered melts of the Bi—Eu system. Keywords: thermochemical properties, melts, compounds, Bi, Eu.

scholarly journals Overview of ytterbium based transparent ceramics for diode pumped high energy solid-state lasers

2018 ◽  
Vol 6 ◽  
Author(s):  
Samuel Paul David ◽  
Venkatesan Jambunathan ◽  
Antonio Lucianetti ◽  
Tomas Mocek
Keyword(s):  
Solid State ◽  
High Energy ◽  
Transparent Ceramics ◽  
Solid State Lasers ◽  
Practical Applications ◽  
Nanosecond Pulses ◽  
Large Size ◽  
Diode Pumped ◽  
Energy Laser ◽  
High Energy Laser

Development of high energy laser sources with nanosecond pulses at several hertz values for repetition rate has been very attractive in recent years due to their great potential for practical applications. With the recent advancement in fabricating large size laser quality transparent ceramics, diode pumped solid-state laser generating pulse energy of 100 J at 10 Hz has been recently realized at HiLASE center using Yb:YAG ceramic with Cr:YAG cladding. This review discusses Yb based high energy lasers, specific laser geometries for efficient thermal management and the role of transparent ceramics in such diode pumped high-energy-class solid-state lasers around the world.

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