发光二极管光、色测试系统

为适应特殊照明用白光发光二极管(white light—emitting diode以下缩写为WLED)研制开发的需要，设计加工了φ100mm的积分球，通过光纤与现有的荧光分光光度计测量单元耦合，构成LED光、色测试系统。该系统首先给出LED的相对光谱功率分布，据此计算出LED的总光通量等光、色参数。这种方法避免了用一般光度计测总光通量时必须进行色修正的麻烦，也避免了因色修正不充分所带来的较大误差。     

用染料明胶制成视见函数修正滤光片

<正> 用光电接收器来测量光的亮度和照度时,为使接收器的视见函数与人眼的视见函数相一致,必须进行修正。视见函数修正滤光片就是用来修正光电接收器的视见函数(如硒光电池、硅光电池、光电管等)与人眼视见函数的差异。     

高功率激光装置输出光束相对光谱功率测量方法

针对SILEX-I超短超强脉冲激光装置输出光束光谱分布的精密测量问题,采用脉冲激光相对光谱功率来评价光谱分布,以溴钨灯为标准光源开展相对光谱功率测量方法的研究,获得相对光谱功率的理论计算公式。以SP2760光栅光谱仪作为光谱测量设备在SILEX-I激光装置上进行了光谱分布测量的验证实验,并给出了不确定度评定,获得了扩展相对不确定度1.7%的测量精度。测量结果显示,相对光谱功率分布与光栅光谱仪的原始光谱响应值分布具有显著的差异,可以更加准确地反映输出脉冲的光谱分布。     

2∽6 GHz范围内二苯并呋喃的纯旋转光谱

本文使用自己搭建的宽带啁啾脉冲傅里叶变换微波谱仪对二苯并呋喃在2∽6 GHz范围内的转动光谱的测量和归属. 对微波光谱的分析获得了40个b型跃迁的归属，精确地确定了旋转常数A=2278.19770(38) MHz、B=601.12248(10) MHz和C=475.753120(98) MHz.     

AgO分子C2∏-X2∏(0,0)带高分辨光谱再研究

本文利用激光诱导荧光技术对AgO分子C²∏-X²∏(0,0)带光谱在∽0.02 cm^-1分辨率水平开展了高分辨研究. 在超声射流条件下利用银针电极对O₂/Ar混合气高压放电制备AgO分子，利用自行研制的窄线宽单纵模光参量振荡器作为可调谐激光光源，实验记录了同位素分辨的¹⁰⁷Ag¹⁶O和¹⁰⁹Ag¹⁶O分子C²∏-X²∏(0,0)带的高分辨光谱. 通过对实验光谱的转动分析获得了两个同位素分子的精确光谱常数，其中¹⁰⁷Ag¹⁶O分子C²∏态常数为首次实验测定. 结合文献和理论计算，实验观测的C²∏态自旋-轨道耦合效应很可能来自于与四重解离态⁴Σ^-或⁴∏的态混合.     

四氯化碳和二硫化碳中乙醇构象异构体布居的羟基伸缩振动拉曼光谱

综合利用拉曼光谱和密度泛函理论研究了乙醇在四氯化碳、二硫化碳溶液中乙醇构象异构体的布居. 首先确定了trans和gauche构象乙醇在OH伸缩振动拉曼光谱中的归属,然后结合理论计算的拉曼散射截面估计了两个异构体的能级差。 可以看出在四氯化碳和二硫化碳中trans乙醇更稳定。通过分析不同温度的拉曼光谱,发现范霍夫方程在这里并不适用. 利用玻尔兹曼分布律和理论拉曼散射截面,发现了两个异构体的能级差随着温度升高而增大,这反映了溶剂与乙醇之间越弱的分子间相互作用更有利于trans构象乙醇的布居。     

彩色PDP中荧光粉发光色坐标的测量方法研究

等离子体显示器已成为平板显示领域主要发展方向之一。在等离子体显示器上测得的色坐标包含了两部分：一部分是荧光粉在PDP器件中发光色的色坐标，一部分是PDP工作时气体放电的色坐标。在PDP屏的制作过程中，荧光粉经历了浆料制备、干燥、烧结以及老炼等工艺过程。因此，荧光粉在PDP屏上表现出的色坐标比起荧光粉体来说会产生一些变化。本文以测量PDP中荧光粉发光色坐标为目的，提出了一种用单色PDP屏色坐标、亮度和同结构下气体放电色坐标、亮度来获得荧光粉在PDP屏中色坐标和亮度的方法，设计制作了测试PDP屏三基色荧光粉发光色坐标所用的单色试验屏。用CRT ColorAnalyzer（CA－100）时PDP屏和PDP屏上气体放电产生的亮度和色坐标都进行了测量，根据合成颜色的在刺激值与二种已知颜色的在刺激值具有线性叠加关系，计算出了荧光粉在PDP器件中的色坐标和亮度。同时，用WGD－3型组合式多功能光栅光谱仪对PDP屏和气体放电的发光光谱进行了测量，用计算机将测得的发光光谱在同波长下相减，从而获得了荧光粉在PDP中的发光光谱。结果表明绿粉和蓝粉的色坐标变化较大，而红粉变化较小，使得PDP白场色温向较低的方向变化。绿粉和蓝粉的发光谱线的半峰宽与原粉比较都有减小，峰值发光强度也减小了，绿粉的峰值发光波长从526nm变至523．4nm。     

两种荧光粉混合涂覆的白光LED的光谱方程的建立

为了有效地模拟两种荧光粉混合涂覆的白光LED的发光光谱,选用了硅酸盐系列的绿色荧光粉与高显粉系列的红色荧光粉,应用英国Edinburgh FLS920P型荧光光谱仪,对绿色荧光粉与红色荧光粉进行荧光光谱的实验测量,得到绿色荧光粉发射峰在527 nm,红色荧光粉发射峰在641 nm。配置浓度为7%~17%,比例为3∶1~3∶2的样本,共144个,应用杭州远方色谱有限公司的HAAS-2000高精度光谱辐射计测量LED发光光谱,最后处理数据,得到拟合函数,在这些函数的基础上构建出了光谱方程,该光谱方程是模拟两种荧光粉的浓度和比例的系统方法。为了较为准确的预测出两种荧光粉混合后涂覆于蓝光芯片的发光光谱,对于实验中的数据进行了三维曲面拟合,得出荧光粉的浓度与比例和绿修正系数与红修正系数之间的函数关系式。将得出的绿修正系数和红修正系数的函数关系式应用到光谱方程中,得出最终模拟白光LED发光光谱的一种新方法。并且用了两组的模拟光谱图与实验的光谱图进行对比,发现两种光谱图的吻合效果都较为良好。说明这种模拟白光LED的新方法确实可行,且预测的两种荧光粉混合后涂覆于蓝光芯片的发光光谱较为准确。该方法将具体的荧光粉的质量比和浓度与LED的发光光谱图联系了起来,而之前的大多数研究都是将光谱功率分布与LED发光光谱图联系起来,并未涉及到荧光粉的质量比与浓度。在建立了具体的光谱方程之后,可以在没有实验仪器和不做实验的情况下,根据两种荧光粉的质量比,以及与AB胶混合后的浓度直接得出最终的模拟白光光谱,可以摆脱实验仪器以及其他因素的限制。并且为制备具有特定光谱特性的白光LED提供了新思路,具有一定的实用价值。     

视场角和定位误差在光谱辐射亮度测量中的影响

为了减小不同光谱辐射计间瞄准区域差异带来的光谱辐射亮度不一致性,讨论了视场角及定位对于测量准确性的影响。通过建立太阳光白板和卤钨灯白板系统光路下的光谱辐射亮度测量模型,分析了不同几何光路视场区域平均辐射亮度与中心辐射亮度的差异。数值模拟表明,太阳光白板光路修正因子仅与视场角大小有关;卤钨灯白板光路修正因子随测量距离增大而减小,距离600 mm时8°和14°视场角的修正因子分别变为0.993 5和0.980 2。最后,实验验证了卤钨灯白板系统下角度误差和位移误差对光谱辐射亮度的影响。结果表明,修正因子对水平方向的角度误差和位移误差呈现非对称性,两侧差异高达2%。因此,依据视场角和几何定位可以对测量结果进行数据修正,有助于提升光谱辐射亮度测量不确定度水平。     

研究表面光学和热学特性的一种新方法——光热位移光谱

本文介绍研究固体、表面及薄膜的光学和热学特性的一种十分灵敏的探测技术。这一探测技术——光热位移光谱,是基于对样品表面吸收电磁辐射后所引起的热膨胀的测量。本技术亦适用于那些要求高真空和温度变化范围较大条件的实验研究工作。这种光谱技术还能将面吸收和体吸收很好的区分开来,入射功率面的吸收的测量能达到αl=10^-6/W.     

光场的非傍轴性对光谱移动和光谱开关的影响

利用瑞利衍射积分公式，推导出多色高斯光束被硬边光阑衍射后光谱的解析公式，傍轴近似的光谱公式可作为特例得到.着重研究了束腰宽度与中心波长之比w₀/λ₀和截断参数δ对光谱移动和光谱开关的影响.结果表明，只有当w₀/λ₀和δ满足一定条件时，傍轴近似结果才与非傍轴结果一致.光场的非傍轴性会引起光谱移动不同和产生光谱开关的临界位置变化. 关键词： 非傍轴光场 高斯光束 光谱移动 光谱开关     

光电探测器相对光谱灵敏度测试方法的研究

本文在全面比较了各类光电器件相对光谱灵敏度S(λ)_r的基础上,设计了用热释电探测器作参考基准,用积分球作单色光辐射接收系统的S(λ)_r测量系统.由于设计上的优点,这一系统大大减少了入射辐射的偏振性,不均匀性,探测器的温漂和杂散辐射等因素带来的误差.     

Geometry of Real Forms of the Complex Neumann System

In the paper, we study real forms of the complex generic Neumann system. We prove that the real forms are completely integrable Hamiltonian systems. The complex Neumann system is an example of the more general Mumford system. The Mumford system is characterized by the Lax pair (L^?(λ), M^?(λ)) of 2 × 2 matrices, where and U^?(λ), V^?(λ), W^?(λ) are suitable polynomials. The topology of a regular level set of the moment map of a real form is determined by the positions of the roots of the suitable real form of U^?(λ), with respect to the position of the values of suitable parameters of the system. For two families of the real forms of the complex Neumann system, we describe the topology of the regular level set of the moment map. For one of these two families the level sets are noncompact.

In the paper, we also give the formula which provides the relation between two systems of the ?rst integrals in involution of the Neumann system. One of these systems is obtained from the Lax pair of the Mumford type, while the second is obtained from the Lax pair whose matrices are of dimension (n+1) × (n+1).     

ZnS:Mn、Cu粉末直流电致发光器件直流和交流电致发光一致性的研究

本文研究了粉末直流电致发光(DCEL)器件在直流(DC)和交流(AC)电压下光电特性的关联和区别及其物理机制.实验发现,在DC和AC条件下DCEL器件的阻抗特性之间没有任何有规律的关联,而AC条件下的激发电流IA和亮度BA以及DC条件下的亮度BD和发光效率ηD四个参量之间则表现出某种程度的一致性,但AC条件下的发光效率ηA与上述四个参量之间却表现出某种相反和相对立的关系.DCEL器件的光电特性具有强烈非线性和对电压方向的非对称性.正半周(或DC条件下)DCEL器件是在高电场和低电流激发下的发光.对发光起主要作用的是电场强度.在负半周时则是低电场和大电流激发下的发光.对发光起主要作用的是激发电流而不是电场强度.在AC条件下依材料、工艺、形成条件和工作电压的不同,DCEL器件可能更多地显示出正半周,负半周或两半周综合的光电特性.上述观点可以解释本文的实验结果.     

A. C. Electroluminescence of CdS : Sm and CdS : Cu,Sm EL phosphors

Electroluminescent CdS : Sm and CdS : Cu, Sm phosphors have been prepared and their EL characteristics are investigated. The brightness waves of these phosphors were measured at a sinusoidal alternating voltages with a frequency of 500 Hz, 1 kHz, 2 kHz and 5 kHz. One primary and one secondary peak have been observed in each half period of the applied sinusoidal field. Time averaged EL brightness has been found to follow the Alfrey-Taylor relationB= =B ₀ exp (–b/V ^1/2) over a wide range of frequencies. Variation of the constants of this relation with frequency of the applied field have been studied. Variation of current across the EL cell with the applied voltage has also been investigated. The EL emission spectra show peaks at 600 and 650 nm in CdS : Sm phosphor whereas in the case of CdS : Cu, Sm phosphor the emission peak occurs at 600 nm. The observed results have been interpreted in terms of acceleration collision theory of the electroluminescence.One of the authors (RKT) expresses his gratitude to the University Grants Commission, New Delhi, for a fellowship and the Principal, S. D. J. Post Graduate College, Chandesar Azamgarh, for study leave.     

Sol-gel synthesis, structural and optical properties of rare earth ions (Sm or Dy) activated Ca3Ga2Si3O12 powder phosphors

Structural, morphological and optical properties of rare earth ions (RE³⁺=Sm³⁺ or Dy³⁺) activated Ca₃Ga₂Si₃O₁₂ (CaGaSi) phosphors synthesized by the sol-gel method are reported. XRD results confirmed the cubic phase structure of RE³⁺:CaGaSi phosphors. From the SEM images of RE³⁺:CaGaSi phosphors, it is observed that the particles are agglomerated. Photoluminescence spectra of Sm³⁺:CaGaSi phosphors have shown bright orange red emission at 598 nm (⁴G_5/2→⁶H_7/2) with an excitation wavelength of λ_exci=401 nm. In the case of Dy³⁺:CaGaSi phosphors bright yellow emission has been observed at 574 nm (⁴F_9/2→ ⁶H_13/2) with λ_exci=451 nm. From the PL spectral results, the rare earth ion concentration of CaGaSi phosphors is optimized.     

Photoluminescence and gamma-ray irradiation of SrAl2O4:Euand Y2O3:Eu phosphors

Y₂O₃:Eu³⁺ phosphor is a very attractive material for use as a red phosphor in many fields. SrAl₂O₄:Eu²⁺ belongs to long lasting phosphor (LLP) and it is a useful bluish-green luminescence material, which can also be a promising candidate as a simple and easy-to-use radiation detection element for visual display of two dimensional radiation distributions. In the present study, both these two kinds of phosphors were synthesized using high temperature solid state reactions. In our work, the influence of gamma-ray irradiation on the properties of these two kinds of phosphors was studied by comparing photoluminescence, brightness and the decay curve of unirradiated and gamma-ray-irradiated samples. Conclusions from the present work can be briefly summarized as follows. In irradiated samples, the brightness is decreased without sensible change in the wavelength distribution of the luminescence spectrum and in the decay kinetic upon gamma exposure. Moreover, the emission due to Eu³⁺→Eu²⁺ conversion in Y₂O₃:Eu³⁺ phosphors was not observed in our sample after irradiation to high exposure. Also the brightness of SrAl₂O₄:Eu²⁺ phosphor turned out to decrease after the exposition to ionizing radiation while the luminescence wavelength distribution remained unchanged. The reason for the effect of gamma-ray irradiation on the properties of phosphors is also discussed in the paper.     

微波热效应合成(Y,Gd)BO3:Eu3+荧光体

本文首次报道用微波热效应法合成(Y,Gd)BO3:EU3+荧光体粉晶材料,X射线粉末衍射确认为六方晶系,晶胞参数a=0.3796nm,c=0.8835nm;在589nm和613.0nm监测下,其激发光谱峰是239.0nm和240.0nm,半高宽40nm.在240.0nm激发下,589nm和612-626nm的荧光强度比为1.9/1.     

Crystal field effects on the photoluminescence properties of Y<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>La<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>VO<Subscript>4</Subscript>:Eu<Superscript>3+</Superscript> phosphors

Y_1−x La _x VO₄:Eu³⁺ phosphors were synthesized using a solid-state reaction. The microstructure and surface morphology of the Y_1−x La _x VO₄:Eu³⁺ phosphors were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. PL measurements of these phosphors revealed the characteristic Eu³⁺ emissions due to ⁵D₀→⁷F₁ and ⁵D₀→⁷F₂ transitions. The Y_1−x La _x VO₄:Eu³⁺ phosphors showed strong red emission at 619 nm, which radiated from the hypersensitive transition ⁵D₀–⁷F₂ of Eu³⁺ ions. In particular, the incorporation of La into the YVO₄ lattice could induce a remarkable increase in PL. The highest emission intensity was observed in Y_0.2La_0.8VO₄:Eu³⁺, whose brightness was increased by more than 100 fold compared to that of the LaVO₄:Eu³⁺ phosphors. The Y_1−x La _x VO₄:Eu³⁺ phosphors with highly enhanced luminescence are expected to have applications in display devices.     

ac anddc electroluminescence in CaS:Cu,Sm phosphors

Theac anddc electroluminescence in CaS:Cu, Sm have been investigated. The luminescence spectra show three peaks in the visible region. The brightness-voltage dependence satisfies the relationB=B ₀ exp (−b/V ^1/2) with two modes of variation. The nature of this dependence indc andac at different frequencies is discussed. The electroluminescence brightness also depends on the temperature of the phosphors and shows a peak around 80.0;C. The electroluminescence efficiency increases with applied voltage up to 2200 V and this dependence on V is explained on the basis of a transport process of the Schottky emission type.