977 resultados para ND Painting


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Nd:silicate glass was implanted at room temperature by 6.0 MeV C3+ ions with a dose of 2.0 x 10(15) ions cm(-2). A waveguide with thickness of about 6.3 mu m was formed. The prism-coupling method was used to observe the dark modes of the waveguide at 633 nm and 1539 nm, respectively. There are three dark modes at 633 nm, of which one is the enhanced-index mode. The propagation loss of the enhanced-index mode in the waveguide measured at 633 nm is 0.42 dB cm(-1) after annealing at 217 degrees C for 35 min. The reflectivity calculation method was applied to simulate the refractive index profiles in the waveguide. The mode optical near-field output at 633 nm was presented.

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Porous glass with high-SiO2 content was impregnated with Nd ions, and subsequently sintered at 1100 degrees C into a compact non-porous glass in air or reducing atmosphere. Sintering in a reducing atmosphere produced an intense violet-blue fluorescence at 394 nm. However, the sintering atmospheres almost did not affect the fluorescence properties in the infrared range. A good performance Nd3+-doped silica microchip laser operating at 1064 nm was demonstrated. The Nd-doped sintering glasses with high-SiO2 content are potential host materials for high power solid-state lasers and new transparent fluorescence materials. (c) 2007 Elsevier B.V. All rights reserved.

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We demonstrate, for the first time as far as Re known, a passively Q-switched operation of a Nd:YVO4 laser in which a Cr4+:YAG crystal and a laser-diode bar are used as the saturable absorber and the pump source, respectively. Stable laser pulses as short as 28 ns with 20-mu J energy can be generated with this laser, which has the advantages of simplicity, high efficiency, and good long-term stability. (C) 1997 Optical Society of America.

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High-quality Nd:LuVO4 single crystal was successfully grown by Czochralski method. The assessment of the crystalline quality by the chemical etching method and Conoscope image was reported. The absorption spectra from 300 to 1000 nm and emission spectra from 960 to 1450 nm of Nd: LuVO4 were measured. Laser performance was achieved with Nd:LUVO4 crystal for the transition of F-4(3/2) -> I-4(11/2) (corresponding wavelength 1065.8 nm) in an actively Q-switched operation, and the average output power reached 5.42 W at a pulse repetition frequency (PRF) of 40 kHz under pump power of 18 W, giving an optical conversion efficiency of 30.1%. The pulse energy and peak power reached 138 mu J and 16.2 kW at PRF of 25 kHz under pump power of 14.2 W, and the pulse duration was 8.5 ns. (c) 2005 Elsevier B.V. All rights reserved.

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将SiO2含量超过97wt%的具有纳米级微孔的多孔高硅氧玻璃浸泡在含有Nd^3+离子的溶液后取出,在1100℃烧结成透明无孔高硅氧玻璃。在800nm的激光抽运下,这种Nd^3+离子掺杂的高硅氧玻璃微片激光器实现了斜率效率为62%,光-光转换效率为42%,波长为1064nm的激光输出。

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应用中频感应提拉法生长了新型的Nd:(La,Sr)(Al,Ta)O3(Nd^3+:LSAT)晶体。运用电感耦合等离子体原子发射光谱仪(ICPAES)测定Nd^3+离子在Nd^3+:LSAT晶体中的分凝系数为0.587。X射线粉末衍射(XRPD)测试结果表明Nd^3+:LSAT晶体与LSAT晶体同构。研究了不同退火条件对晶体光谱性能的影响。分析了Nd^3+:LSAT晶体的光谱性能,Nd^3+:LSAT晶体的荧光寿命为290μs。比较了Nd^3+:LSAT和Nd^3+:YAG,Nd^3+:YVO3等晶体的光谱

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成功制备了高质量的Nd:YAG透明陶瓷,激光测试样品的尺寸为3mm×3mm×3mm,双面抛光、未镀膜,最高连续输出能量为1003mW,斜率效率为14%.

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The fluorescence emission spectra of Cr:Nd:YAG crystal are measured and the effective stimulated emission cross-section of the crystal is obtained from -80 to +80 degrees C. A linear temperature dependence between -80 and +80 degrees C is reported for the 1.064-mu m peak stimulated emission cross-section of Cr:Nd:YAG crystal. (C) 2005 Elsevier Ltd. All rights reserved.

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由于Nd^3+离子半径0.112nm和Y^3+离子半径0.101nm相差10.9%,使得Nd^3+离子非常难于进入YAG晶体中。我们用温度梯度法生长了大尺寸高浓度(2.8 at%)的Nd:YAG晶体,同时与用提拉法Nd:GGG晶体进行了比较。分析了高浓度掺杂Nd:GGG和Nd:YAG晶体浓度猝灭问题。研究了不同浓度掺杂的猝灭效应。在同样的掺杂浓度下,我们发现它们的猝灭程度不同,其原因是两种晶体中△Emism(-)和(+) △Emism(+) 不同。

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Large sized neodymium-doped Y3Al5O12 (Nd:YAG) laser crystals have been grown by temperature gradient technique (TGT) method and compared with Czochralski (Cz) method. The comparison of these two crystal growth methods has been listed. The results showed that the TGT method has many advantages over the Cz method. The concentration distribution of Nd ions in the crystals was determined and the absorption spectra of these crystals have been investigated and compared. The TGT grown highly doped Nd:YAG crystal has a larger absorption FWHM than that of Cz grown Nd:YAG crysral. Highly doped Nd:YAG (similar to 2.8 at. pct) crystals could be obtained by TGT.

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用温度梯度法(TGT)生长了大尺寸的Nd:YAG激光晶体,测试了室温下的吸收谱并利用吸收谱研究了Nd离子在YAG晶体中的分布。比较了温度梯度法与提拉法生长晶体的区别。根据热容激光的原理,利用生长的Nd:YAG激光晶体片设计了热容激光器,利用侧面抽运,获得了1200w的激光输出,工作时间为2s,光-光转换效率为30%。

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近年来Nd:YAG多晶陶瓷作为激光介质得到了越来越多的重视,我国在这个方向也开展了大量的研究工作,Nd:YAG多晶陶瓷与Nd:YAG单晶相比有很多优点:容易制造、成本低、可以制造大尺寸和高掺杂浓度的材料,且无浓度梯度,机械特性良好,硬度比单晶大1.5倍,断裂韧度比单晶大5倍,并且可制备多层和多功能的陶瓷结构、可大批量生产,已经获得了比Nd:YAG单晶更高的效率,因此钇铝石榴石透明陶瓷是理想的钇铝石榴石单晶激光介质材料替代品。但国产陶瓷由于质量不佳,透明度不是很高,一直未能获得激光输出。

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用提拉法生长了掺铬、钕的钆镓石榴石(Cr^4+,Nd^3+:GGG)自调Q激光品体。报道了室温下的吸收光谱和荧光光谱特性。分析了Cr离子浓度对光谱性质的影响。比较了Cr^4+:GGG,Nd^3+:GGG和(Cr^4+,Nd^3+):GGG晶体吸收光谱的关系。测量了(Cr^4+,Nd^3+):GGG晶体和Nd^3+:GGG晶体的荧光寿命,它们分别是33μs和250μs。实验表明,(Cr^4+,Nd^3+):GGG晶体是一种非常有潜力的自调Q激光晶体,可以实现大功率激光器的小型化和全固态化。

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用提拉法生长了掺铬、钕的钆镓石榴石(Cr^4+,Nd^3+:GGG)晶体,研究了室温下的吸收光谱和荧光光谱性质,以及晶体中Cr离子浓度对Nd离子光谱性质的影响。应用Judd—ofelt理论计算了强度参数Ωt(t=2,4,6),自发辐射跃迁几率、荧光分支比和辐射辱命等光谱参数。应用McCumber理论计算^4F3/2→^4I11/2能级跃迁的受激发射截面。结果表明:Cr^3+在300~900nm之间较强地增加了吸收截面,尤其是伴随Cr^3+→Nd^3+有效的能量转移。Cr^4+在1.06μm附近的吸收减弱了