Study of photon-induced L3 vacancy alignment for elements La to U

Alignment of photon-induced L₃ vacancies is studied in rare earth and highZ elements at energies of experimental interest, near thresholds to 60 keV, under nonrelativistic dipole approximation. Numerical calculations of the matrix element are undertaken to produce theoretical data for comparison with the experimental findings. The A₂ values being s>0.1 at photoelectron energies <20 keV are certainly higher than 5–8% uncertainties quoted in experimental results. Present findings are from a very basic model, hydrogen-like and can further be treated as reference to observe the impact of screening, relativistic, multipole and retardation corrections to the model     

利用计算机辅助装调检测矩形大口径离轴非球面的方法研究

通过非球面的零位补偿法,完成了对矩形大口径离轴非球面镜的检测。先用光学设计软件Zemax从理论上分析了在检测中会出现的现象,并结合计算机辅助装调技术,确定在检测过程中相对敏感的自由度,然后控制这些量,使补偿器和非球面的相对关系与理论设计相吻合,在Zygo相位干涉仪上测得最终结果。在λ=632.8nm时,中心圆口径与两个边缘圆口径面形误差RMS分别为0.022λ,0.037λ,0.032λ。检测结果,达到预期目的。     

基于矢量波像差理论的计算机辅助装调技术研究

在三阶矢量波像差理论的基础上,建立了系统内失调量与系统波像差Zernike系数的关系式,并以共轴三反射光学系统为数学模型进行了仿真分析.结果表明,基于矢量波像差理论的装调技术可行,并可用于大型光学系统的装调.利用该理论对一共轴非球面三反系统进行装调,最终使系统波像差RMS<0.080λ.     

高功率激光装置光束准直系统新型远场监测技术

利用高功率激光装置空间滤波器小孔成像和取样光栅的衍射,设计出一套新型光路远场监测方案,并且在实验平台上进行了实验验证.实验结果表明：相对传统的远场监测方法,该远场监测系统通过侧面离轴光栅取样灵活利用空间,其调整平均误差为空间滤波器小孔直径0.9%,能够满足准直系统远场调整精度(<小孔直径5%)的要求. 关键词： 激光技术 光束准直 光栅 远场     

Band alignment regulation of HfO2/SiC heterojunctions induced by PEALD with in situ NH3-plasma passivation

The efficient passivation of in situ NH₃-plasma pre-treatment and its regulation of the band alignment between HfO₂ and 4H-SiC have been investigated by XPS. With in situ NH₃-plasma passivation by PEALD, a VBO of 0.72 eV and a CBO of 1.54 eV can be obtained across the HfO₂/4H-SiC interface. The Si-O bonds components reduction in the passivated interface layers will lead to band bending or band shift at the interface and regulate the band alignments between HfO₂ and 4H-SiC. The physical mechanism investigation of band alignments can be a cornerstone for the application of HfO₂/4H-SiC heterojunctions in the high-power devices.     

基于空穴注入层摩擦定向的偏振蓝光聚合物电致发光器件

研究了利用摩擦空穴注入层3,4-乙撑二氧噻吩:聚苯乙烯磺酸(PEDOT:PSS)作为定向层实现聚芴(PFO)薄膜的偏振电致发光,蓝光的色坐标为(0.20,0.21).从聚合物薄膜的紫外可见吸收和光致发光偏振特性,研究了不同定向层摩擦强度、退火温度以及退火时间下PFO薄膜的二向色性,并证明退火温度是决定器件偏振性能的关键因素.当摩擦强度为25 mm退火温度和时间分别为200℃和30 min时,得到较好的偏振性能,器件的电致发光偏振率约为3. 关键词： 偏振发光 摩擦定向 聚合物电致发光 空穴注入层     

Magnetic alignment in nominally non-magnetic hexagonal metal hydrides: NMR

Powders of three hexagonal metal-hydrides or -deuterides are found to align in 4.4–8.3 T magnetic fields used for NMR. The field-alignment is unexpected, since all three systems have very small susceptibilities, as demonstrated by sharp NMR lines. The extent of alignment runs from nearly complete to barely detectable in ZrBe₂(H,D)_x, LuD₃, and YD₃, respectively. The preferred alignment direction in ZrBe₂(H,D)_x is with the crystallites’ c-axis perpendicular to B, while the c-axis and B tend to be parallel in LuD₃ and YD₃. The susceptibilities χ_|| and χ are determined from bulk magnetization measurements in aligned ZrBe₂H_1.4 powder. The alignment must be considered for proper analysis of NMR spectra in these and related materials.     

光学工程分析中的镜面面形处理新方法

光学系统在载荷的作用下会发生变形。基于干涉检验理论,提出了一种先调整后再拟合的处理方法。首先利用下山法计算光学镜面在法线方向的变形;然后利用Zernike多项式拟合变形曲面得到Zernike系数;最后去除刚体位移,作等高线图。新的数据处理方法可以更好的与干涉检验保持一致。对某相机的主镜进行仿真试验,结果表明,下山法计算效率较高,先调整后再拟合的处理结果与干涉检验结果的一致性较好。     

非稳腔中调腔孔对光束质量的影响

在中、远红外波段的激光器中，组成谐振腔的反射镜基底材料多数是对可见光不透明的，采用在腔镜上开一小孔输入调腔光方法是最简便的。本文用Ｆｏｘ－Ｌｉ迭代法计算了无开孔及有开孔时正支非稳共焦腔空腔的模式，结果表明当调腔光开孔直径小于３ｍｍ时，对光束质量基本没有影响。