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1.
宁凯杰  张庆礼  周鹏宇  杨华军  许兰  孙敦陆  殷绍唐 《物理学报》2012,61(12):128102-128102
采用提拉法成功生长尺寸为φ30 mm× 75 mm的15at.%Yb3+:Gd2SiO5单晶, 并用Reitveld全谱拟合方法确定了其晶格常数、原子坐标和温度因子等参数. 用吸收光谱计算了Yb3+离子2F7/22F5/2能级跃迁的振子强度、谱线强度、跃迁概率、 能级寿命和积分发射截面等光谱参数, 并根据激光性能评估得出结论: 表明该晶体具有较大的阈值特性, 有望采用大功率激光二极管泵浦实现可调谐或超快激光输出.  相似文献   

2.
采用中频感应提拉法生长了高质量的Tm:Y2SiO5(Tm:YSO)晶体,测定了晶体的晶格常数和分凝系数.运用劳厄照相法确定了单斜晶系Tm:YSO晶体的三个偏振轴〈010〉,D1D2,在室温下测量了三个偏振轴方向的吸收光谱、荧光光谱和荧光寿命,计算了晶体吸收峰的吸收线宽和吸收截面.研究发现,相对于其他两个偏振轴方向,D1方向在790nm处出现较强的吸收峰,关键词:2SiO5')\" href=\"#\">Tm:Y2SiO5单斜晶系吸收光谱荧光光谱  相似文献   

3.
杨秋红  曾智江  徐军  苏良碧 《物理学报》2006,55(6):2726-2729
采用传统无压烧结工艺制备Mg,Ti共掺透明氧化铝陶瓷,测定了其吸收光谱、荧光光谱和激发光谱,结果表明,由于Mg2+的电荷补偿,当Ti掺入量较小时,Ti主要以Ti4+形式存在,(Mg,Ti):Al2O3透明陶瓷只在250nm的紫外波段有吸收峰,为O2-→Ti4+的电荷转移跃迁产生的吸收,并产生Ti4+离子在280—290nm和410—420nm的荧光发射峰  相似文献   

4.
谭鑫鑫  吕树臣 《光子学报》2014,39(7):1169-1175
采用共沉淀法制备了纳米晶ZrO2-Al2O3∶Er3+发光粉体.所制备的粉体室温下具有Er3+离子特征荧光发射,主发射在绿光,其中位于547 nm、560 nm的绿光最强,并得出稀土离子与基质之间有能量传递.对不同煅烧温度下的样品研究表明:因不同温度下所制得的样品晶相不同.研究了纳米晶ZrO2-Al2O3∶Er3+及ZrO2-Al2O3∶Er3+/Yb3+的上转换发光,并分析了上转换的跃迁机制.发现ZrO2-Al2O3∶Er3+的绿光为双光子过程,而ZrO2-Al2O3∶Er3+、Yb3+的上转换光谱中,红光和绿光也为双光子过程,而极弱的蓝光为三光子过程.讨论了Er3+的浓度猝灭现象.最适宜掺杂浓度的原子分数为2%(Er3+/Zr4+).  相似文献   

5.
Ag+掺杂的立方相Y2O3:Eu纳米晶体粉末发光强度研究   总被引:1,自引:0,他引:1  
采用化学自燃烧法制备了不同Ag+掺杂浓度的Y2O3:Eu纳米晶体粉末样品([Y3+]∶[Eu3+]∶[Ag+]=99∶1∶X,X=0—3.5×10-2),以及通过退火处理得到了相应的体材料.根据X射线衍射谱确定所得纳米和体材料样品均为纯立方相.实验表明在纳米尺寸样品中随着Ag离子浓度的增加,荧光发射强度随之增加,当X=2×10-2时达到最大值,其发光强度比X=0时提高了近50%.当Ag离子浓度继续增加,样品发光强度保持不变.在相应的体材料样品中则没有观察到此现象.通过对各样品的发射光谱,激发光谱,X射线衍射图谱,透射电镜(TEM)照片和荧光衰减曲线的研究,分析了引起纳米样品荧光强度变化的原因是由于Ag离子与表面悬键氧结合,从而使这一无辐射通道阻断,使发光中心Eu3+的量子效率提高;Ag+的引入所带来的另一个效应是使激发更为有效.这两方面原因使发光效率得到了提高.  相似文献   

6.
苟婧  王育华  李峰  何玲 《物理学报》2006,55(8):4310-4314
用硝酸盐热分解法成功制备了BaZr(BO3)2:Eu(Eu3+的掺杂量为摩尔分数5%)荧光材料,并研究了其在254及147nm光束激发下的发光特性.254nm光束激发下的发射主峰位于612nm处,归属于Eu3+5D07F2的电偶极跃迁,但在147nm光束激发下的发射主峰位于592nm处,归属于Eu3+相似文献   

7.
Yb:YAG晶体的热学性质及其对激光性能的影响   总被引:1,自引:1,他引:1  
对于中频感应加热提拉法(Czochralski Method)生长的高掺杂浓度(原子数分数0.30)Yb:YAG晶体,经退火后采用差示扫描量热计法测量了晶体的比热容,通过激光脉冲法测量了不同掺杂浓度(原子数分数0.05-0.30Yb:YAG晶体的热扩散率和热导率。实验表明,随着Yb^3 离子浓度增加,Yb:YAG晶体在300K温度下的导热性能有明显的降低。原子数分数为0.30的Yb:YAG晶体的激光实验表明,高掺杂浓度Yb:YAG晶体热导率的降低导致了激光阈值的增加。  相似文献   

8.
 以乙醇钽、钛酸丁酯为原料,以乙醇为溶剂,通过溶胶-凝胶法及超临界干燥成功制备了Ta2O5-TiO2复合气凝胶。用场发射扫描电镜(SEM)、透射电镜(TEM)、扫描电镜模式下的电子能谱仪(EDS)以及比表面积吸附仪(BET)对其进行表征。结果表明:该气凝胶是由粒径在nm量级的Ti和Ta的羟基氧化物胶体颗粒堆积而成的低密度、高比表积的多孔网络结构材料,孔径分布主要集中在5~15 nm,比表面积为492.9 m2/g,密度为90 mg/cm3左右。  相似文献   

9.
Yb:YAG晶体的光谱性能   总被引:10,自引:0,他引:10  
系统地研究了不同掺杂浓度的Yb:YAG晶体的光谱特性,通过吸收光谱的测量计算了晶体的吸收截面,用对易法计算了晶体的发射截面。在Yb:YAG晶体毛坯中发现Yb^2+和色心,其浓度随Yb:YAG晶体中Yb^3+的增加而增加。经1400℃氧气氛退火后消失。首次用光子激发和X射线激发研究了Yb:YAG晶体的荧光特性。  相似文献   

10.
在室温及不同的氧氩比条件下,采用射频磁控溅射Ag层和直流磁控溅射SnO2层,在载玻片衬底上制备出了SnO2/Ag/SnO2多层薄膜.用霍尔效应测试仪、四探针电阻测试仪和紫外-可见-近红外光谱仪等表征了薄膜的电学性质和光学性质.实验结果表明:当氧氩比为1:14时,所制得的薄膜的光电性质优良指数最大,为1.69×10-2 Ω-1;此时,薄膜的电阻率为9.8×10-5 Ω·cm,方电阻为9.68 Ω/sq,在400~800 nm可见光区的平均光学透射率达85%;并且,在氧氩比为1:14时,利用射频磁控溅射Ag层和直流磁控溅射SnO2层在PET柔性衬底上制备出了光电性质优良的柔性透明导电膜,其在可见光区的平均光学透过率达85%以上,电阻率为1.22×10-4 Ωcm,方电阻为12.05 Ω/sq.  相似文献   

11.
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陆神洲  杨秋红 《中国物理 B》2012,21(4):47801-047801
Yb:Sc2O3 transparent ceramics are fabricated by a conventional ceramic process and sintering in H2 atmosphere. The room-temperature spectroscopic properties are investigated, and the Raman spectrum shows an obvious vibration characteristic band centred at 415 cm-1. There are three broad absorption bands around 891, 937, and 971 nm, respectively. The strongest emission peak is centred at 1.04 μm with a broad bandwidth (11 nm) and an emission cross-section of 1.8×10^-20 cm^2. The gain coefficient implies a possible laser ability in a range from 990 nm to 1425 nm. The energy-level structure shows that Yb:Sc2O3 ceramics have large Stark splitting at the ground state level due to their strong crystal field. All the results show that Yb:Sc2O3 transparent ceramics are a promising material for short pulse lasers.  相似文献   

12.
在半导体激光器高功率抽运的镱、钠共掺氟化钙(Yb, Na:CaF2)激光器中, 通过对晶体的负热透镜效应的数值模拟,进行激光器腔型的调节和优化,使得该激光器在采用2%的耦合输出镜和吸收抽运功率为7.8 W的条件下,获得了脉冲宽度为190 fs、平均输出功率为503 mW、中心波长为1034 nm、重复频率为82.4 MHz的连续锁模脉冲序列. 如果计算晶体表面反射等其他形式的泄漏输出,激光器的总平均输出功率为905 mW.关键词:Yb2晶体')\" href=\"#\">Na:CaF2晶体激光二极管抽运飞秒激光  相似文献   

13.
    
A single-crystal CaF2 (111) was irradiated with single and multiple laser (Ti:sapphire, 800 nm, 25 fs) shots at fluences ranging from 0.25 to 1.5 J cm?2. In this fluence regime, a single laser pulse usually leads to typical bump-like features ranging from 200 nm to 1.5 μm in diameter and 10–50 nm in height. These bumps are related to compressive stresses due to a pressure build-up induced by fast laser heating and their subsequent relaxation. When CaF2 is irradiated with successive (in our case 20) shots at a laser fluence of 1.5 J cm?2, nanocavities at the top of the microbumps are observed. The formation of these nanocavities is regarded as an explosion and is attributed to the explosive expansion generated by shock waves due to laser-induced plasma after the nonlinear absorption of the laser energy by the material. Such kinds of surface structures at the nanometre scale could be attractive for nanolithography.  相似文献   

14.
A promising WC-Co-Cu-BaF2/CaF2 self-lubricating wear resistant coating was deposited via atmospheric plasma spraying (APS) process by using homemade feedstock powders composed of WC-Co, Cu and BaF2/CaF2 eutectic. The as-prepared cermet coatings had better frictional behavior comparing with the WC-Co coating. Moreover, the often-occurred decarburization of WC in APS process was noticeably improved due to the binding of copper and BaF2/CaF2 phase, which not only offered effective solid lubrication, but also acted as bind phases to mend the microstructure and protected WC from decomposition. The optimized specimen contained 10 wt.% Cu and 10 wt.% BaF2/CaF2 in a WC-Co matrix, which had excellent frictional and wear performance. The wear mechanism of the self-lubricating wear resistant coating was discussed with the microstructures, compositions and mechanical properties of the composite materials in detail.  相似文献   

15.
ZnO thin films were grown on (111) CaF2 substrates by magnetron sputtering at room temperature. Structural and optical properties of the ZnO thin films were studied. XRD analysis showed that the ZnO thin films had the (002) preferential orientation. The transmittance of ZnO thin films was over 80% in the visible range. The optical band gap of the ZnO thin films was 3.26 eV. The optical constants (n,k)(n,k) of the ZnO thin films in the wavelength range 300–1000 nm were obtained by infrared spectroscopic ellipsometry measurement. PL spectra of ZnO thin films showed strong UV near-band-edge emission peak at 376.5 nm and weak visible red emission at 643.49 nm using He–Cd laser as the light source, using a synchrotron radiation light source PL spectra showed three emission peak at 320 nm, 410 nm and 542 nm respectively.  相似文献   

16.
Abstract

Ion implantation can be used to introduce network damage and to alter the chemical composition in glasses. Structural changes can be inferred from IR measurements near 1000 cm?1 and by optical absorption near 2150 Å. Implantation-induced damage decreases the implanted volume in fused silica with consequent changes in the refractive index, the near-surface hardness, and the tensile surface stress. Prior work in these areas is reviewed. Implantation into alkali silicate glasses depletes the alkali content in the implanted region. These changes allow preferential surface crystallization in Li2O-2SiO2 glasses. Crystallization of amorphous SiO2 can be induced by implantation of Li. Insight into the crystallization process is obtained by following the associated ion movement by elastic recoil detection (ERD) and optical techniques. Implantation of 20keV H shows that saturation of implanted H-sites in fused silica occurs at about 2.2 × 1021 H/cm3 in agreement with free volume estimates of the maximum number of available interstitial sites. Details of H and D interactions in fused silica were studied as a function of fluence and temperature. Results are of interest in studies of corrosion in glasses considered for nuclear waste encapsulation and for components in fusion reactors.

IV Summary  相似文献   

17.
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Transparent Yb doped YAG, YSAG and YaLaO3 ceramics are fabricated by using the co-precipitation method. The spectral properties and thermal parameters of these Yb doped cubic phase transparent ceramics are compared, and their different and potential applications are also analysed. The absorption cross-section and the emission cross-section of these ceramics are measured and calculated. The essential properties of these materials especially for the rep-rated pulsed high-energy diode-pumped solid-state lasers are investigated. The results show that Yb doped YAG, YSAG and YaLaO3 are all suitable materials used for diode-pumped solid-state lasers.  相似文献   

18.
The preparation of benzoic acid-functionalized CaF2:Ln3+ (Ln = Eu or Tb) nanoparticles and their sensitized luminescence are described in this report. First, to achieve sufficient proof for energy transfer from benzoic acid (BA) to lanthanide ions doped in nanoparticles, we employ Eu3+ as the microscopic probe and investigate the luminescent spectra of benzoic acid-functionalized CaF2:Eu3+ (BA-CaF2:Eu3+) nanoparticles. Next, to further reveal the difference between sensitized luminescence and common luminescence for Eu3+ doped in CaF2 nanoparticles, we study the emission spectra of BA-CaF2:Eu3+ nanoparticles excited at 286 nm and 397 nm, respectively. Finally, we analyze and compare the luminescent spectra of BA-CaF2:Tb3+ and CaF2:Ce3+, Tb3+ nanoparticles in detail. Our results indicate that both Eu3+ and Tb3+ doped in CaF2 nanoparticles can be efficiently sensitized through benzoic acid.  相似文献   

19.
Yb:FAP和Yb:C_3S_2-FAP晶体光谱的温度特性和选择激发   总被引:1,自引:0,他引:1       下载免费PDF全文
报导了Yb :FAP和Yb :C3S2 _FAP晶体在不同温度下的吸收光谱和荧光光谱实验结果 ,研究发现由于电子_声子近共振耦合作用 ,Yb :FAP和Yb :C3S2 _FAP晶体均存在有明显的振动谱 ,Yb :FAP晶体的零声子线在低温下还劈裂为相差 10cm- 1 的两条线 .采用激光选择激发技术研究了Yb3 离子在FAP和C3S2 _FAP晶体中的格位特征 ,结果表明Yb3 离子在这两种基质中都只占据Ca(Ⅱ )格位 ,但由于CaF2 的挥发 ,导致了Ca(Ⅱ )格位的局部畸变 .  相似文献   

20.
Yb:Sc2O3 transparent ceramics are fabricated by a conventional ceramic process and sintering in H2 atmosphere. The room-temperature spectroscopic properties are investigated, and the Raman spectrum shows an obvious vibration characteristic band centred at 415 cm 1 . There are three broad absorption bands around 891, 937, and 971 nm, respectively. The strongest emission peak is centred at 1.04 μm with a broad bandwidth (11 nm) and an emission cross-section of 1.8×10 20 cm 2 . The gain coefficient implies a possible laser ability in a range from 990 nm to 1425 nm. The energy-level structure shows that Yb:Sc 2 O 3 ceramics have large Stark splitting at the ground state level due to their strong crystal field. All the results show that Yb:Sc2O3 transparent ceramics are a promising material for short pulse lasers.  相似文献   

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