有机电致发光过程中扩散系数的Monte-Carlo模拟

用Monte-Carlo方法对有机电致发光的注入,迁移,复合过程进行了模拟,得到了δ函数电脉冲的扩散系数随时间变化的关系。通过分析,发现有机电致发光器件的物理特性可以通过两个基本的特性参数来表征：激活中心能纺方差σ,电场△E。通过将δ函数电脉冲扩散系数推广到直流电压时扩散系数对ITO／ROPPV（60nm)/Alq(40nm)/Al器件的电致变色现象进行了讨论。     

掺镱光纤激光器的多波长振荡特性

利用Sagnac梳状滤波器,研究了环形腔掺镱光纤激光器(YDFL)在室温和77 K时的多波长振荡行为。结果表明,在室温和77 K时,掺镱光纤(YDF)均呈现明显的非均匀加宽效应,使得掺镱光纤激光器的起振波长数随抽运光功率的提高而增多。但在室温下,因均匀加宽效应强,掺镱光纤增益的非均匀加宽并不能补偿其内禀不平坦的增益谱,造成波长缺失现象,且当波长间隔减小至0.8 nm时,均匀加宽效应引起的波长竞争造成了多波长振荡的稳定性下降。而在77 K时,掺镱光纤非均匀加宽效应明显增强,在0.8 nm的波长间隔下,无波长缺失现象,将起振波长数增加到32个,且多波长振荡稳定。     

Investigation of the growth and optical properties of a Co~(2+)-doped Na_5Lu_9F_(32) single crystal

A 0.1 mol.% CoF_2-doped Na_5Lu_9F_(32)single crystal with high quality in the size of ～φ10 mm×100 mm was grown by the Bridgman method. Three peaks located at 504, 544, and 688 nm and a broad band in the range of 1200–1600 nm centered at 1472 nm were observed in the absorption spectra. The absorption peak position suggests cobalt ions in the divalent state in the grown crystal. Moreover, the cobalt ions are confirmed to locate in the distorted cubic crystal structure. Upon excitation of 500 nm light, a sharp emission peak at 747 nm ascribed to the ~2T_2(H_1) →~4A_2(F) transition was observed for the crystal. The Co~(2+)-doped Na_5Lu_9F_(32)crystal shows a potentially promising material for the application of a passively Q-switched laser operating in the near-infrared range.     

Optical properties of Cr3+ doped Na5Lu9F32 single crystals grown by the Bridgman method

The growth of Na5Lu9F32 single crystals doped with Cr3+ ions in 0.1 mol%, 0.2 mol% and 0.5 mol% concentrations by Bridgman method was reported. The optical absorption and luminescence spectra decisively demonstrate that the Cr dopant enters Na5Lu9F32 as Cr3+. Fluorescence emission at wavelengths of 418 nm, 444 nm, 653 nm and 678 nm can be observed under the excitation of 372 nm and the fluorescence lifetime at 418 nm was measured to be ~10.31 μs. The possible crystal sites for Cr3+ ions in Na5Lu9F32 single crystal were discussed, and the lattice parameter Dq, Racach parameters B and C were estimated.     

微喇曼和红外光谱法研究化学气相沉积金刚石多晶膜结晶质量特性

研究了化学气相沉积多晶膜的宏观性能(颜色和透光性)与微观性能(结晶质量、相纯度和氢杂质含量)之间的关系,喇曼谱与金刚石膜中氢杂质含量(红外光谱测得)的关联性.给出了根据颜色和透明度来区分样本膜质量的实验依据,颜色较深的膜的结晶质量差、相纯度低、氢杂质含量高,1 332 cm 1金刚石特征喇曼峰强度低,半峰宽大.由于多晶...     

Manifestation of attosecond XUV fields temporal structures in attosecond streaking spectrogram

The features of an attosecond extreme ultraviolet (XUV) field are encoded in the attosecond XUV spectrogram. We investigate the effect of the temporal structures of attosecond XUV fields on the attosecond streaking spectrogram. Factors such as the number of attosecond XUV pulses and the temporal chirp of attosecond XUV pulses are considered. Results indicate that unlike the attosecond streaking spectrogram for an attosecond XUV field with two pulses of a half-cycle separation of streaking field, the spectrogram for the attosecond XUV field with three pulses demonstrates fine spectral fringes in separated traces.     

AlF3基氟化物玻璃中Eu3+的光谱性质与局域结构的关系

报导了Eu^3 掺杂AlF3基氟化物玻璃材料的制备及其光谱性质与局域结构的关系。声子边带谱表明与稀土离子的电子跃迁相耦合的声子模式为Al-F的伸缩振动模,结合^151Eu的Mossbauer谱,进一步确认了Eu^3 在该玻璃基质中的配位状态。由发射光谱,根据AlF3晶体所属空间群中等效点系的对称性分析,通过对称性破缺可以推测Eu^3 在该玻璃体系中占据的格位主要为Ci和S6。     

用光子级联发射测量SrAl12O19中Pr3+3P0能级的量子效率

在SrAl12O19中，Pr^3 的^1S0处于4f5d之下，可以观察到光子级联发射。研究了SrAl12O19:Pr^3 的光谱性质。把第一步发射的谱线强度作为第二步发射起始能级上电子数的度量，测量了SrAl12O19:Pr,Mg中Pr^3 3P0能级的量子效率，测量结果反映了浓度猝灭的影响。低浓度样品中可见区发射的量子效率约为70％，它显著小于1的原因可能是^1I6的热激发。     

环形腔振动敏感度的研究

为了降低环形腔的环境振动敏感度,设计了一个四柱支撑环形腔。利用有限元数值模拟的方法,通过改变支柱的支撑位置和支柱直径,对环形腔进行数值模拟,得到了环形腔光程变化量随各参数变化的关系曲线。结果表明,通过选择适当的支撑位置和支柱直径,可以使得光程变化量趋近零,光程对振动不敏感。该方法对于高稳定环形腔的设计具有重要的指导意义。