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| {{chembox
| | Oscar is how he's known as and he completely enjoys this title. To collect cash is what his family and him appreciate. North Dakota is our birth place. For many years he's been working as a receptionist.<br><br>Also visit my web site: [http://simple-crafts.com/groups/best-techniques-for-keeping-yeast-infections-under-control/ std home test] |
| | verifiedrevid = 476994790
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| | ImageFile = Linbo3 Unit Cell.png
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| | ImageSize = 150px
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| | ImageFile2 =
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| | IUPACName =
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| | OtherNames =
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| | Section1 = {{Chembox Identifiers
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| | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
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| | ChemSpiderID = 10605804
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| | InChI = 1/Li.Nb.3O/q+1;;;;-1/rLi.NbO3/c;2-1(3)4/q+1;-1
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| | InChIKey = GQYHUHYESMUTHG-YHKBGIKBAK
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| | SMILES = [Li+].[O-][Nb](=O)=O
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| | StdInChI_Ref = {{stdinchicite|correct|chemspider}}
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| | StdInChI = 1S/Li.Nb.3O/q+1;;;;-1
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| | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
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| | StdInChIKey = GQYHUHYESMUTHG-UHFFFAOYSA-N
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| | CASNo = 12031-63-9
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| | CASNo_Ref = {{cascite|correct|CAS}}
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| | PubChem = 159404
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| }}
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| | Section2 = {{Chembox Properties
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| | Formula = LiNbO<sub>3</sub>
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| | MolarMass = 147.846 g/mol
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| | Appearance = colorless solid
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| | Density = 4.65 g/cm<sup>3</sup> <ref name=CT>[http://www.crystaltechnology.com/docs/LN_LTAppNote.pdf Spec sheet] of Crystal Technology, Inc.</ref>
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| | MeltingPt = 1257 °C<ref name="CT" />
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| | BoilingPt =
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| | Solubility = None
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| | SolubleOther =
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| | RefractIndex = n<sub>o</sub> 2.30, n<sub>e</sub> 2.21<ref>{{cite web |url=http://www.luxpop.com |title=Luxpop |accessdate= June 18, 2010}} (Value at ''n''<sub>D</sub>=589.2 nm, 25 °C.)</ref>
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| | BandGap = 4 eV
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| }}
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| | Section3 = {{Chembox Structure
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| | CrystalStruct = [[trigonal]]
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| | SpaceGroup = R3c
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| | PointGroup = 3m (C<sub>3v</sub>)
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| | Coordination =
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| | Dipole =
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| }}
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| | Section4 = {{Chembox Thermochemistry
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| | DeltaHf =
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| | DeltaHc =
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| | Entropy =
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| | HeatCapacity =
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| }}
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| | Section7 = {{Chembox Hazards
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| | ExternalMSDS =
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| | EUIndex = Not listed
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| | MainHazards =
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| | NFPA-H =
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| | NFPA-F =
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| | NFPA-R =
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| | NFPA-O =
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| | FlashPt =
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| }}
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| | Section8 = {{Chembox Related
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| | OtherAnions =
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| | OtherCations =
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| | OtherCpds =
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| }}
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| '''Lithium niobate''' ({{Lithium}}{{Niobium}}{{Oxygen|3}}) is a compound of [[niobium]], [[lithium]], and [[oxygen]]. Its single crystals are an important material for optical waveguides, mobile phones, piezoelectric sensors, optical modulators and various other linear and non-linear optical applications. | |
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| ==Properties==
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| Lithium niobate is a colorless solid insoluble in water. It has a [[trigonal]] [[crystal system]], which lacks [[inversion symmetry]] and displays [[ferroelectricity]], [[Pockels effect]], [[piezoelectric]] effect, [[photoelasticity]] and [[nonlinear optics|nonlinear optical]] polarizability. Lithium niobate has negative uniaxial [[birefringence]] which depends slightly on the [[stoichiometry]] of the crystal and on temperature. It is transparent for wavelengths between 350 and 5200 [[nanometer]]s.
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| Lithium niobate can be doped by [[magnesium oxide]], which increases its resistance to optical damage (also known as photorefractive damage) when doped above the [[optical damage threshold]]. Other available dopants are {{iron}}, {{zinc}}, {{hafnium}}, {{copper}}, {{gadolinium}}, {{erbium}}, {{yttrium}}, {{Manganese}} and {{boron}}.
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| ==Growth==
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| [[Single crystal]]s of lithium niobate can be grown using the [[Czochralski process]].<ref>{{cite book|title = Lithium Niobate: Defects, Photorefraction and Ferroelectric Switching|first = Tatyana|last = Volk|coauthors = Wohlecke, Manfred|publisher = Springer|year = 2008|isbn = 978-3-540-70765-3|doi=10.1007/978-3-540-70766-0|pages=1–9}}</ref> [[File:Lithium Niobate Wafer.jpg|175px|thumb|A Z-cut, single crystal Lithium Niobate wafer|left]] After a crystal is grown, it is sliced into wafers of different orientation. Common orientations are Z-cut, X-cut, Y-cut, and cuts with rotated angles of the previous axes.<ref>{{cite book|last=Wong|first=K. K.|title=Properties of Lithium Niobate|year=2002|publisher=INSPEC|location=London, United Kingdom|isbn=0 85296 799 3|pages=8}}</ref>
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| ==Nanoparticles==
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| Nanoparticles of lithium niobate and [[niobium pentoxide]] can be produced at low temperature.<ref>{{cite journal|author = Grange, R.; Choi, J.W.; Hsieh, C.L.; Pu, Y.; Magrez, A.; Smajda, R.; Forro, L.; Psaltis, D. |title = Lithium niobate nanowires: synthesis, optical properties and manipulation |journal = Applied Physics Letters|volume = 95|pages = 143105|year = 2009|url =http://link.aip.org/link/?APPLAB/95/143105/1}}</ref> The complete protocol implies a LiH induced reduction of NbCl<sub>5</sub> followed by ''in situ'' spontaneous oxidation into low-valence niobium nano-oxides. These niobium oxides are exposed to air atmosphere resulting in pure Nb<sub>2</sub>O<sub>5</sub>. Finally, the stable Nb<sub>2</sub>O<sub>5</sub> is converted into lithium niobate LiNbO<sub>3</sub> nanoparticles during the controlled hydrolysis of the LiH excess.<ref>{{cite journal|author = Aufray M, Menuel S, Fort Y, Eschbach J, Rouxel D, Vincent B|title = New Synthesis of Nanosized Niobium Oxides and Lithium Niobate Particles and Their Characterization by XPS Analysis|journal = Journal of Nanoscience and Nanotechnology|volume = 9|issue = 8|pages = 4780–4789|year = 2009|doi = 10.1166/jnn.2009.1087}}</ref> Spherical nanoparticles of lithium niobate with a diameter of approximately 10 nm can be prepared by impregnating a mesoporous silica matrix with a mixture of an aqueous solution of LiNO<sub>3</sub> and NH<sub>4</sub>NbO(C<sub>2</sub>O<sub>4</sub>)<sub>2</sub> followed by 10 min heating in an IR furnace.<ref>{{cite journal|author = Grigas, A; Kaskel, S |title = Synthesis of LiNbO<sub>3</sub> nanoparticles in a mesoporous matrix |journal = Beilstein Journal of Nanotechnology|volume = 2|pages = 28–33|year = 2011|doi =10.3762/bjnano.2.3}}</ref>
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| ==Applications==
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| Lithium niobate is used extensively in the telecoms market, e.g. in [[mobile telephone]]s and [[optical modulator]]s. It is the material of choice for the manufacture of [[surface acoustic wave]] devices. For some uses it can be replaced by [[lithium tantalate]], {{lithium}}{{tantalum}}{{oxygen|3}}. Other uses are in [[laser]] [[second harmonic generation|frequency doubling]], [[nonlinear optics]], [[Pockels effect#Pockels cells|Pockels cell]]s, [[optical parametric oscillator]]s, [[Q-switching]] devices for lasers, other [[acousto-optic effect|acousto-optic]] devices, [[optical switch]]es for gigahertz frequencies, etc. It is an excellent material for manufacture of [[optical waveguide]]s.
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| It's also used in the making of optical spatial low-pass ([[Anti-aliasing_filter|anti-aliasing]]) filters.
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| ==Periodically poled lithium niobate (PPLN)==
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| '''Periodically poled lithium niobate''' ('''PPLN''') is a domain-engineered lithium niobate crystal, used mainly for achieving [[quasi-phase-matching]] in [[nonlinear optics]]. The [[ferroelectric]] domains point alternatively to the ''+c'' and the ''-c'' direction, with a period of typically between 5 and 35 [[micrometre|µm]]. The shorter periods of this range are used for [[second harmonic generation]], while the longer ones for [[Optical parametric oscillator|optical parametric oscillation]]. [[Periodic poling]] can be achieved by electrical poling with periodically structured electrode. Controlled heating of the crystal can be used to fine-tune [[phase matching]] in the medium due to a slight variation of the dispersion with temperature.
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| Periodic poling uses the largest value of lithium niobate's nonlinear tensor, d<sub>33</sub>= 27 pm/V. Quasi-phase matching gives maximum efficiencies that are 2/π (64%) of the full d<sub>33</sub>, about 17 pm/V
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| Other materials used for [[periodic poling]] are wide [[band gap]] inorganic crystals like [[potassium titanyl phosphate|KTP]] (resulting in [[periodically poled KTP]], [[PPKTP]]), [[lithium tantalate]], and some organic materials.
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| The periodic poling technique can also be used to form surface [[nanostructure]]s.<ref>{{cite journal |title=Surface nanoscale periodic structures in congruent lithium niobate by domain reversal patterning and differential etching |author=S. Grilli |coauthors=P. Ferraro, P. De Natale, B. Tiribilli, and M. Vassalli |journal=Applied Physics Letters |volume=87 |issue=23 |pages=233106 |year=2005 |doi=10.1063/1.2137877}}</ref><ref>{{cite journal |title=Modulating the thickness of the resist pattern for controlling size and depth of submicron reversed domains in lithium niobate
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| |author=P. Ferraro |coauthors=S. Grilli |journal=Applied Physics Letters |volume=89 |issue=13 |pages=133111 |year=2006 |doi=10.1063/1.2357928}}</ref>
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| However, due to its low photorefractive damage threshold, PPLN only finds limited applications: at very low power levels. MgO doped lithium niobate is fabricated by periodically poled method. Periodically poled MgO doped lithium niobate (PPMgOLN) therefore expands the application to medium power level.
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| ==Sellmeier equations==
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| The [[Sellmeier equation]]s for the extraordinary index are used to find the poling period and approximate temperature for quasi-phase matching. Jundt<ref name=Jundt>{{cite journal| author=Dieter H. Jundt| journal=Optics Letters|volume=22 |title=Temperature-dependent Sellmeier equation for the index of refraction <math>n_e</math> in congruent lithium niobate| year=1997|pages=1553–5 |doi=10.1364/OL.22.001553| pmid=18188296| issue=20}}</ref> gives
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| <math>n^2_e =
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| 5.35583 + 4.629 \times 10^{-7} f
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| + {0.100473 + 3.862 \times 10^{-8} f \over \lambda^2 - (0.20692 - 0.89 \times 10^{-8} f)^2 }
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| + { 100 + 2.657 \times 10^{-5} f \over \lambda^2 - (11.34927 )^2 }
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| - 1.5334 \times 10^{-2} \lambda^2 </math>
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| valid from 20-250 °C for wavelengths from 0.4 to 5 [[micrometre|micrometer]]s, whereas for longer wavelength,<ref name=Deng>{{cite journal|author=LH Deng et al.|journal = Optics Communications|volume=268| title=Improvement to Sellmeier equation for periodically poled LiNbO<math>_3</math> crystal using mid-infrared difference-frequency generation|issue=1|year=2006| pages=110|doi=10.1016/j.optcom.2006.06.082}}</ref>
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| <math>n^2_e =
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| 5.39121 + 4.968 \times 10^{-7} f
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| + {0.100473 + 3.862 \times 10^{-8} f \over \lambda^2 - (0.20692 - 0.89 \times 10^{-8} f)^2 }
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| + { 100 + 2.657 \times 10^{-5} f \over \lambda^2 - (11.34927 )^2 }- (1.544 \times 10^{-2} + 9.62119 \times 10^{-10} \lambda) \lambda^2 </math>
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| which is valid for ''T'' = 25 to 180 °C, for wavelengths λ between 2.8 and 4.8 micrometers.<br>
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| In these equations f = (T-24.5)(T+570.82), λ is in micrometers, and T is in °C.
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| ==See also==
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| <!-- alphabetic order -->
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| {{colbegin|3}}
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| *[[Crystal]]
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| *[[Crystal structure]]
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| *[[Crystallite]]
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| *[[Crystallization]] and [[Crystallization (engineering aspects)|engineering aspects]]
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| *[[Seed crystal]]
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| *[[Single crystal]]
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| *[[Laser-heated pedestal growth]]
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| *[[Micro-Pulling-Down]]
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| {{colend}}
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| ==References==
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| {{reflist|2}}
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| ==Further reading==
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| *{{cite book|title=Ferroelectric Crystals for Photonic Applications Including Nanoscale Fabrication and Characterization Techniques |series=Springer Series in Materials Science |volume= 91 |editor-last=Ferraro |editor-first=Pietro |editor2-last=Grilli |editor2-first=Simonetta |editor3-last=De Natale |editor3-first=Paolo |url=http://www.springer.com/materials/book/978-3-540-77963-6|doi=10.1007/978-3-540-77965-0}}
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| ==External links==
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| *[http://www.inrad.com/pdf/Inrad_datasheet_LNB.pdf Inrad data sheet on lithium niobate]
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| {{Lithium compounds}}
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| [[Category:Lithium compounds]]
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| [[Category:Niobates]]
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| [[Category:Ferroelectric materials]]
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| [[Category:Nonlinear optical materials]]
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| [[Category:Crystals]]
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| [[Category:Second-harmonic generation]]
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Oscar is how he's known as and he completely enjoys this title. To collect cash is what his family and him appreciate. North Dakota is our birth place. For many years he's been working as a receptionist.
Also visit my web site: std home test