Effect of Fe impurity on the optical loss of Nd-doped phosphate laser glass

The optical loss coefficient at 1053-nm wavelength, influenced by Fe ions in N31-type Nd-doped phosphate laser glass, was determined precisely and analyzed in detail. It is found that the optical loss coefficient per unit of Fe concentration (cm^(-1)/ppmw) increases with Fe concentration in the range of 0---300 ppmw, but it approaches a constant as the Fe concentration is larger than 300 ppmw. Such a concentration effect is due to a shift in the redox equilibrium between Fe3+ and Fe2+ ions in the glass. The effect of oxygen pressure, temperature, and variable valence states of other metal ions in glass samples on the optical loss is also discussed.

热处理对共沉淀法制备YAG纳米粉体性能的影响

以Al（NO3）3和Y（NO3）3为原料，采用共沉淀法制备出粒度大小为60-100nm，颗粒呈球形的纯相YAG纳米粉。研究了前驱物在不同条件下热处理对YAG纳米粉体性能的影响，并对前驱物在焙烧过程中的物相变化进行了观察。发现延长前驱物在低温下的干燥时间会导致晶粒尺寸增大，而采用在晶化温度前后分别进行保温的方法可在较低的温度获得纯相的YAG粉体。对比了焙烧温度和保温时间对产物粒度的影响，结果表明：在保证粉体晶化完全的前提下，升高焙烧温度比延长保温时间对晶粒尺寸有更显著的影响。

Property studies of optical waveguide formed by 6.0 MeV carbon ion implantation into Nd : silicate glass

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.

Fluorescence properties and laser demonstrations of Nd-doped high silica glasses prepared by sintering nanoporous glass

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.

室温下连续波运行Tm:YAP泵浦的Ho:YAG激光器

我们报道了一种以二极管泵浦的 1.94 μm Tm:YAP激光器为泵浦源，常温下在2.1 μm连续运行的Ho:YAG激光器。最大输出功率1.5 W，相应斜率效率为17.9%，二极管到的转换效率为5.6%。

Infrared (1.2-1.6 mu m) luminescence in Yb, Cr : YAG with 940 nm diode pumping

Infrared (1.2-1.6 mum) luminescence in a yttrium aluminium garnet (YAG) crystal, co-doped with Yb (10 at.%) and Cr (0.05 at.%) ions, was investigated under CW laser diode pumping (lambda = 940 nm). The Cr4+ emission band was observed with its peak at 1.35 mum and measured to be about 6% with respect to Yb3+ IR luminescence (lambda = 1.03 mum). Analysis of the crystal absorption and luminescence spectra allows one to conclude that Yb3+-Cr4+ energy transfer is a mechanism responsible for the B-3(2)(T-3(2))-B-3(1)((3)A(2)) emission of Cr4+ ions. This crystal is promising as an efficient source of the near infrared emission. (C) 2004 Elsevier B.V. All rights reserved.

Growth of excellent-quality Nd : LuVO4 single crystal and laser properties

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.

Yb：YAG晶体的红外闪烁特性

用脉冲电子束激发测量了不同Yb^3+掺杂浓度的Yb：YAG晶体的红外(IR)闪烁发光性能。Yb：YAG晶体的IR闪烁发光具有高的光产额和长的衰减时间，但存在浓度猝灭效应和温度依赖关系。Yb：YAG晶体的IR闪烁性能还与晶体品质有关，相同掺杂浓度的Yb：YAG晶体，品质优异的会获得更高的光产额。这一初步的研究成果表明，部分掺Yb^3+晶体有可能用于医学成像装置。

Yb：YAG晶体的合作发光现象

研究了Yb：YAG晶体的合作发光现象。当用940hm的近红外光激发时，Yb：YAG晶体有明显的上转换蓝色发光。实验发现498nm的蓝色发光强度与激发功率的平方成正比，而且Yb^3＋掺杂浓度越高，蓝色发光越强。分析表明这是Yb^3＋间强的相互作用导致的合作发光，是由于Yb^3＋在共价性的YAG基质中，它的4f^I3电子易于与近邻离子发生相互作用导致的。

Temperature dependence of the 1.03 mu m stimulated emission cross section of Cr : Yb : YAG crystal

The fluorescence emission spectra of Cr:Yb:YAG crystal are measured and the effective stimulated emission cross section of the crystal are obtained from -80 degrees C to +80 degrees C. A linear temperature dependence between -80 degrees C and +80 degrees C is reported for the 1.03 mu m peak stimulated emission cross section of Cr:Yb:YAG crystal. (c) 2004 Elsevier B.V. All rights reserved.

掺Nd^3＋离子的高硅氧玻璃微片激光器

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。