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 共查询到19条相似文献,搜索用时 281 毫秒
1.
NaF:OH^—晶体色心及其在氮分子激光照射下的光谱特性   总被引:1,自引:1,他引:0  
冯志萍  王存达 《光学学报》1995,15(8):046-1049
对NaF晶体和NaF:OH^-晶体在电子束辐照前后及在氮分子激光作用下的红外和紫外光谱进行了研究。认为激光强度能否使OH^-分解,决定着F^+2心的再生或退电离。  相似文献   

2.
低温宽带NaCl(OH^—):(F^+2)H色心激光的实验研究   总被引:2,自引:1,他引:1  
林碧洲  许承晃 《光学学报》1994,14(4):46-350
在NaCl晶体中掺入OH^-离子可以有效地提高F^+2心的稳定性。采用四镜折迭X型像散补偿腔,获得了峰值波长1.57μm、输出功率>250mW的低温宽带NaCl(OH^-):(F^+2)H色心激光。本文着重讨论OH^-对F^+2心的稳定作用和影响色心激光振荡的各种因素。  相似文献   

3.
在NaCl晶体中掺入OH-离子可以有效地提高心的稳定性.采用四镜折迭X型像散补偿腔,获得了峰值波长1.57μm、输出功率>250mW的低温宽带NaCl(OH-):色心激光.本文着重讨论OH-对心的稳定作用和影响色心激光振荡的各种因素.  相似文献   

4.
研究了K+对NaCl(OH-)中(F+2)H心的形成及其光谱性质的影响。结果表明,K+的存在抑制了F+2型心的形成,改变了(F+2)H心的光谱性质,拓宽了发射谱的半功率谱宽。从而修正了Polock的实验结果。同时指出,研制具有更宽波长发射范围的Na1-xKxCl(OH-)复合基质F+2型色心激光材料是可能的  相似文献   

5.
DETA对γ—FeOOH制备过程的影响   总被引:2,自引:0,他引:2  
在以FeSO4和NaOH为原料制备铁黄时,反应初期加入EDTA能诱导γ-FeOOH的生成。当初始反应液中EDTA的浓度大于某一临界值C^*时,才能得到纯γ-FeOOH,且C^*随碱比和温度的升高而增大。γ-FeOOH粒子成核期内Fe(Ⅱ)/Fe(Ⅲ)=2,EDTA分子中以一定距离分隔的2个羧基是诱导γ-FeOOH粒子成核的关键基团,由于聚丙烯酸分子的聚软性,其也可以诱导γ-FeOOH的生成。  相似文献   

6.
文中报进了有关辅助光对NaCl(OH~-)及KCl(Na~+,OH~-):色心激光输出功率影响的主要研究结果。初步探讨了辅助光作用的物理机制。  相似文献   

7.
给出了NaF及其掺杂质Li^+、Mg^2+、Cu^2+和OH^-五种样品的F2心在偏振的氮分子激光照射下的二向色性吸收特性,对各种样品中F2心的转向效率进行了比较,并对结果进行了机理性的分析。  相似文献   

8.
氧化态K—MoO3/γ—Al2O3催化剂结构的EXAFS研究   总被引:1,自引:0,他引:1  
对Na2MoO4.2H2O,MoO3,(NH4)6Mo7O24.4H2O等结构典型的含钼化合物及氧化态K-MoO3/γ-Al2O3催化剂样品进行了EXAFS测试,并以Na2MoO4.2H2O为标样进行多层拟合计算,以研究各样品钼组分的配位结构。  相似文献   

9.
测定了NaCl-RbCl-H2O及KCl-RbCl-H2O两种混合电解质体系不同离子强度配比下的电导数据,应用现代Onsager-Fuoss-Chen理论,以经验性线项代替理论中的高次项,得到关联方程,研究了混合电解质溶液的混合效应,发现不同配比下的呈负效应,但效应不明显。  相似文献   

10.
陈宝玖  孔样贵 《发光学报》1999,20(4):300-304
设计并制备了一种Tm^3+、Yb^3+共掺杂的多氟化物调整碲酸盐(MFT)玻璃材料,其组份为50TeO2-14.PbF2-10AlF3-10BaF2-10NaF-0.1Tm2O3-5Yb2O3。测量了该玻璃系统的Raman散射光谱,在970nmLD激发下裸眼可以观察到很强的蓝色我,光谱测量证实这个蓝色发射(476nm)来源于^1G4→^3H6的跃迁,同时,还有两个较弱的红色发射源于^1G4→^3H  相似文献   

11.
赵岩  冯钟潮  梁勇 《中国物理》1998,7(8):618-622
When laser pulses irradiate the surface of the sample WO3, an interesting coloration effect is obtained. Only by one pulse of XeCl laser irradiation (wavelength: 308 nm, pulse duration: 36 ns, output power: 100 mJ/pulse), a significant color change appears. X-ray photoelectron spectroscopy (XPS) shows that a partial reduction process of WO3 occurs and conduction band electrons appears. X-ray diffraction pattern indicates that the lattice parameters of the colored samples are increased. A molten layer can be seen in scanning electron microscopy (SEM) image. It may be concluded that the coloration effect of pulsed laser undergoes a process different from that of electro- or photo- chromism, and may be attributed to thermochromism and substoichiometric WO3 is formed. The coloration process is characterized by its high speed and stability.  相似文献   

12.
l.IntroductionowingtotheirpromisingproPertiesandPOtentialapplications,transitionmetalni-trideshavedrawngreatattentionandthepreparationandinvestigationofthesecom-poundshavebeenasubjectbothofscientificandoftechnologicalinterest.Transitionmetalnitridescombineadvantagesofexce1lenthardness,highmeltingPOint,goodchemi-calstabilityandhigheIectricalconductivity[11,henceoverlaySofthesecompoundshavefoundwideappIicationsinvariousfie1ds.Molybdenumnitrides,inparticular,havealsoemergedasverypromisingcandi…  相似文献   

13.
姚杰  陈宝琼  王宏楷 《物理学报》1985,34(1):117-120
本文研究了p型硅单晶用红宝石脉冲激光辐照之后向n型转化的效应。这个效应与补偿杂质有关。实验结果表明:脉冲激光辐照之后补偿杂质浓度增加,补偿杂质磷分布发生变化,杂质补偿度大于7%的样品在被激光辐照的区域较容易转变为n型导电。这个效应与硅单晶中氧含量、晶面和晶体生长方式无关。 关键词:  相似文献   

14.
对于沸点相近并且分子自由程相差不大的物质,常规分离方法难以实现有效的分离,激光分离有效地弥补了常规分离方法的不足.用脉冲CO2激光器和连续CO2激光器对大豆卵磷脂混合物进行了激光分离实验,用高效液相色谱对激光辐照前后的样品进行了分析.经192.31 W/cm2的脉冲CO2激光辐照,卵磷脂的质量分数相对提高了26.7%,...  相似文献   

15.
Crystallization is induced by pulsed laser irradiation of s-deposited amorphous Ge2Sb2Te5 films. Changes of the irradiated areas have been analyzed with the reflectivity contrast. As laser fluences increasing,the reflectivity contrast increases from 0% - 2% to 14% - 16%, which indicates the structure of as deposited films transforms from amorphous to crystalline phases. The process of crystallization driven by the movement and rearrangement of atoms is described. And also the influence of the pulse duration on the threshold of crystallization is discussed, the results show that a lower threshold of crystallization can be produced for as-deposited films irradiated by the laser with short pulse duration. However, by the laser with long pulse duration, crystallization can only be formed with a higher threshold. The crystallization of films by irradiation of laser pulses is studied by Raman spectra.  相似文献   

16.
We report on experimental data of chemical compounds formed in the damaged area at the surface of certain optical ZnSe windows subjected to multi-pulse microsecond pulsed TEA-CO2 laser irradiation in air. The results are analysed from the viewpoint of implication of the oxidation process activated under the action of CO2-laser power in plasma initiation and evolution of surface damage process.  相似文献   

17.
In the present work, nanosecond pulsed laser crystallization, dewetting and ablation of thin amorphous silicon films are investigated by time-resolved imaging. Laser pulses of 532 nm wavelength and 7 ns temporal width are irradiated on silicon film. Below the dewetting threshold, crystallization process happens after 400 ns laser irradiation in the spot central region. With the increasing of laser fluence, it is observed that the dewetting process does not conclude until 300 ns after the laser irradiation, forming droplet-like particles in the spot central region. At higher laser intensities, ablative material removal occurs in the spot center. Cylindrical rims are formed in the peripheral dewetting zone due to solidification of transported matter at about 500 ns following the laser pulse exposure.  相似文献   

18.
This paper describes a novel process of nanoparticle synthesis by pulsed laser ablation of consolidated microparticles. Metal microparticles, including Cu, Al and Ag, are consolidated by a cold isobaric press with pressures up to a few hundred MPa before laser irradiation. Nanoparticles are then synthesized in air by high-power pulsed laser ablation of the microparticles using a Q-switched Nd:YAG laser. It is shown that the degree of compaction plays a significant role in determining the size of the produced nanoparticles. The effect of laser fluence and collector position on the distribution of particle size is examined. Photoacoustic deflection probing and nanosecond time-resolved visualization indicate that the novel process attains increased efficiency of laser-energy coupling with the target. PACS 81.07.-b; 81.07.Wx; 42.62.Cf  相似文献   

19.
Continuous wave(CW) laser irradiation is employed to enhance the pulsed laser ablation of silicon and stainless steel(316 L)samples. Different surface temperatures generated by the CW laser irradiation are set as the initial working circumstance for the pulsed laser ablation. The diameter and depth of laser-ablated craters are measured to study threshold fluence, pulse incubation coefficient and ablation rate under different surface temperatures. Numerical simulation employing Heat Transfer in Solid and Deformed Geometry Interface modules in COMSOL is performed to estimate ablation rate theoretically based on Hertz-Knudsen equation. The realized crater-related data are analyzed to further obtain their dependences on surface temperature. The parametric and morphological studies indicate that the weakened plasma shielding effect and thermal diffusion in the ablated region induced by the CW laser irradiation lead to the enhanced pulsed laser ablation significantly.  相似文献   

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