200～400nm波段光电探测器光谱响应度测量装置研究

本文叙述了200~400nm波段光电探测器光谱响应度的测量装置原理、测量系统及不确定度。采用紫外光谱强度大的氙灯作为光源,采用紫外分光效率高的单色仪进行分光,腔型热释电探测器与标准硅光电探测器进行相对光谱响应比较得到标准硅光电探测器相对光谱响应度。绝对值标定则是利用低温辐射计对无窗紫敏硅光电探测器进行测量后再传递到标准硅光电探测器,从而最终测量出标准硅光电探测器在紫外波段的绝对光谱响应度。     

400～1700 nm绝对光谱响应度校准和量值传递

介绍了高准确度光辐射功率校准原理和方法,利用低温辐射计作为主标准器,以陷阱探测器作为传递标准,激光器作为光源,通过激光功率稳定装置,校准了硅陷阱探测器和铟镓砷陷阱探测器的绝对光谱响应度。选取476.1, 488, 514.7, 521, 568, 632.8, 647.1, 785, 852, 980, 1064, 1550,nm共12条谱线完成了校准实验,绝对光谱响应度测量不确定度均优于0.05%。通过量子效率模型得出了硅陷阱探测器的绝对光谱响应曲线。利用InGaAs陷阱探测器分立波长点的绝对光谱响应度与相对光谱响应曲线进行了验证分析。结果表明,2种陷阱探测器均可用作传递标准进行高准确度的可见光和近红外光辐射功率校准和量值传递。     

真空紫外-软X射线波段（5～105nm）探测器校准装置的研制

介绍了中国计量科学研究院在真空紫外.软X射线波段(5～105nm)探测器标准研究的新进展.介绍了建立在中国科学技术大学国家同步辐射实验室的以稀有气体电离室为标准探测器的探测器校准装置,以及利用该电离室作为基准探测器对作为传递标准探测器的硅光电二极管的量子效率测量的结果,在5～35nm范围内,相对标准不确定度为18%～20%.与NIST的结果相比,有较好的符合.     

碳量子点的一步合成及其发光性质的研究

本文采用油浴加热柠檬酸一步法合成碳量子点,用HRTEM透射电镜和FTIR红外光谱对其形貌和结构进行表征。研究该碳量子点的荧光性质,初步探讨了其发光的可能机理。实验结果表明,该方法合成的碳量子点粒径大小为3~5 nm,在360 nm处有一个很强的紫外吸收峰,最大激发波长和发射波长分别为365 nm和460 nm,其光学稳定性良好,在pH5.0~7.0范围内,碳量子点的荧光强度随pH的变化比较敏感。     

掺氮荧光碳量子点的制备及性能研究

以柠檬酸为碳源、对氨基苯甲酸为氮源，通过一步水热法制备了氮掺杂荧光碳量子点(N-CQDs),采用透射电子显微镜、傅里叶变换红外光谱仪、稳态瞬态荧光磷光光谱仪对其形貌、结构和光谱进行表征，研究了反应温度、反应时间、酸碱度对N-CQDs荧光性能的影响。结果表明：N-CQDs呈球形，具有良好的分散性；N-CQDs的荧光强度较碳量子点增强约17倍，N-CQDs最佳激发波长为404nm,最佳发射波长为480nm,说明氮的掺杂有助于碳量子点荧光强度的增强；反应温度为180℃、反应时间为6h,酸碱度为中性时，N-CQDs荧光强度最强。     

基准光电高温计的光谱响应度测量

基准光电高温计的光谱响应度是复现ITS-90银点以上温标的重要参数,中国计量科学研究院新建了一套基于单色仪的光谱响应度测量装置.在这套装置上高温计的光谱响应度作为一个整体参数进行测量,系统能够自动完成单色仪的波长标定和高温计的响应度测量.初步完成了基准光电高温计的600～1 200 nm之间的光谱响应度测量,并计算了基准光电高温计的有效波长及其不确定度.     

多量子阱红外探测材料的光致荧光谱

在多量子阱红外探测器外延材料制备中,由于器件响应波长对量子阱的阱宽和垒高变化敏感,因此对外延材料的制备有很高的要求.本文中我们利用光致荧光谱(PL)对GaAs/AIGaAs多量子阱红外探测器材料进行了测量和计算,从而在器件工艺前,快速确定器件的探测波长.以光致荧光光谱对GaAs/AIGaAs多量子阱红外探测器材料进行测试,通过理论计算,得到多量子阱红外探测器探测波长.计算得到的理论响应波长与实际器件的响应波长有良好的一致性,证明用光荧光谱对外延材料进行测量并计算,能够更加有效地开展器件研究工作.同时,我们在低温下测量了外加偏压下器件暗电流情况,以及液氮温度下,500K黑体辐射情况时,信号噪声比达到235.3.     

小球藻内叶绿素a荧光特征的研究

由于叶绿素a外环境极性的不同,其荧光行为有很大的改变。通过小球藻体内叶绿素荧光光谱特性的研究,发现其体内叶绿素的激发波长有在丙酮溶剂中的相同,均为430 nm,但发射波长为680 nm,红移了13 nm。利用小球藻的叶绿素荧光强度进行水体中叶绿素a的定量检测,在浓度为1~100μg/L的浓度范围内,相对荧光强度与叶绿素浓度有很好的相关性,线性方程为y=0.5338x+1.8515,线性相关系数R2为0.9974。     

一种便携式多波段光谱辐射计的研制

为满足空间光学遥感仪器地面定标设备校准的应用需求,基于标准探测器的辐亮度传递原理,研制光阑筒式结构的多波段辐射计。介绍多波段辐射计的工作原理和研制过程,该仪器具有10个测量通道,利用窄带干涉滤光片进行分光,工作波段分布于400~1 000 nm之间,辅以视场光阑、孔径光阑限制入射面积及立体角,以硅光电二极管探测器作为探测部件实现辐亮度高精度测量。该仪器具有自校准光源监测系统的稳定性,并利用CCD瞄准器实现观测目标的可视化,测量过程方便。对该仪器光谱辐亮度测量不确定度进行评估,其测量不确定度优于1.30%。     

PTB高精度紫外线光谱响应率分度

PTB以低温电替代辐射计为基础 ,建立了波长范围在 2 0 0nm～ 4 0 0nm之间的光电探测器光谱响应率标准。为了获得低不确定度连续波长范围的标准 ,组合使用了存储环BESSYⅠ的色散同步加速器辐射和准单色激光辐射。利用单色同步加速器辐射和激光辐射的特性 ,在 4 0 0nm～ 2 0 0nm的光谱范围内 ,探测器校准已达到了 1 0 - 3 和 5× 1 0 - 3 之间的相对标准不确定度。     

Excitation-emission fluorimeter based on linear interference filters

We describe the design, properties, and performance of an excitation-emission (EE) fluorimeter that enables spectral characterization of an object simultaneously with respect to both its excitation and its emission properties. Such devices require two wavelength-selecting elements, one in the optical path of the excitation broadband light to obtain tunable excitation and the other to analyze the resulting fluorescence. Existing EE instruments are usually implemented with two monochromators. The key feature of our EE fluorimeter is that it employs lightweight and compact linear interference filters (LIFs) as the wavelength-selection elements. The spectral tuning of both the excitation and the detection LIFs is achieved by their mechanical shift relative to each other by use of two computer-controlled linear step motors. The performance of the LIF-based EE fluorimeter is demonstrated with the fluorescent spectra of various dyes and their mixtures.     

Calibration of the Irradiance Responsivity of a Filter Radiometer for T Measurement at NIM

At the National Institute of Metrology of China (NIM), silicon photodiode-based narrow-band interference filter radiometers (FRs) have been designed for the radiometric determination of the thermodynamic temperature. The FR calibrations were performed on a new spectral comparator with a trap detector which was calibrated against the cryogenic radiometer at several discrete laser lines. The new spectral comparator is constructed from two grating monochromators assembled to give lower stray light and higher transmitted flux. Applying a transmittance measurement of the filter in the out-of-band region and careful control of the temperature, the irradiance responsivity of a 633 nm centered FR has been obtained over a dynamic range of nearly eight decades in the wavelength range from 450 nm to 1200 nm. The relative standard uncertainty of the responsivity is also analyzed and estimated to be less than 7 × 10^?4 at the 1 ?? level.     

红外探测器光谱响应率定标方法

采用新的方法对波长范围1-3μm的红外探测器绝对光谱响应率进行定标.红外探测器的光谱响应率定标是在两套定标系统上利用两种参考探测器实现的.首先在红外光谱比较系统上利用一个平响应的腔式热电堆探测器作为参考探测器,测量待测红外探测器相对于标准探测器的连续光谱响应率;然后在可见一近红外定标系统上,利用低温辐射计和激光器在几个单立波长上进行绝对光谱响应率测量.这样,通过计算就能得出待测红外探测器在每个波长上的绝对光谱响应率.采用上述方法对TS-76探测器进行光谱响应率定标,联合不确定度小于0.95%.     

Excitation wavelength dependence of water-window line emissions from boron-nitride laser-produced plasmas

We investigated the effects of laser excitation wavelength on water-window emission lines of laser-produced boron-nitride plasmas. Plasmas are produced by focusing 1064 nm and harmonically generated 532 and 266 nm radiation from a Nd:YAG laser on BN target in vacuum. Soft x-ray emission lines in the water-window region are recorded using a grazing-incidence spectrograph. Filtered photodiodes are used to obtain complementary data for water-window emission intensity and angular dependence. Spectral emission intensity changes in nitrogen Ly-α and He-α are used to show how laser wavelength affects emission. Our results show that the relative intensity of spectral lines is laser wavelength dependent, with the ratio of Ly-α to He-α emission intensity decreasing as laser wavelength is shortened. Filtered photodiode measurements of angular dependence showed that 266 and 532 nm laser wavelengths produce uniform emission.     

固体荧光样品寻峰方法探讨

特征激发峰值和发射峰值位置是荧光材料的两个重要参数。文中提出一种固体荧光样品的快速寻峰方法一固体对比法。该方法采用光谱平坦的高漫反射板为中介，利用测得的样品信号和高漫反射板信号间的内在联系，通过计算消除了仪器光源、探测器响应等诸多因素对测量结果的影响，保证了测量结果的正确可靠。该方法对非白校准型荧光光谱仪以及白校准型荧光光谱仪均能适用，且测量过程简单，测量结果精度高。     

Next-Generation NASA Airborne Oceanographic Lidar System

The complete design and flight test of the next-generation Airborne Oceanographic Lidar (AOL-3) is detailed. The application of new technology has allowed major reductions in weight, volume, and power requirements compared with the earlier AOL sensor. Subsystem designs for the new AOL sensor include new technology in fiber optics, spectrometer detector optical train, miniature photomultiplier modules, dual-laser wavelength excitation from a single small laser source, and new receiver optical configuration. The new design reduced telescope size and maintained the same principal fluorescence and water Raman bands but essentially retained a comparable measurement accuracy. A major advancement is the implementation of single-laser simultaneous excitation of two physically separate oceanic target areas: one stimulated by 532 nm and the other by 355 nm. Backscattered fluorescence and Raman signals from both targets are acquired simultaneously by use of the same telescope and spectrometer-detector system. Two digital oscilloscopes provide temporal- and depth-resolved data from each of seven spectral emission bands.     

基于CCD器件的苯甲酰脲类农药荧光检测系统

根据苯甲酰脲类农药在紫外光的照射下能够发出荧光的机理,设计了一种基于CCD(电荷耦合器件)的检测该类有机农药残留的光纤荧光测量系统.该系统以脉冲氙灯为激发光源,利用光纤探测和传输荧光,采用线阵CCD代替传统的光电倍增管作为荧光信号的光电检测元件,同时配备A/D高速数据采集卡,实现了单片机控制下荧光信号的光电转换以及数据采集,进而实现了对卡死克和盖虫散(氟铃脲)农药浓度的测量.实验结果表明,在激发波长分别为290nm和345nm时,卡死克和盖虫散的荧光强度分别在360nm和418nm处达到最大,最低检出限分别为12 μg/L和20 μg/L.在25～1 000μg/L范围内,荧光强度和溶液浓度基本呈线性关系.该测量系统灵敏度高,线性范围宽,可以满足荧光检测的要求.     

Measurement of the Fluorescence Quantum Yield Using a Spectrometer With an Integrating Sphere Detector

A method is proposed for measuring the fluorescence quantum yield (QY) using a commercial spectrophotometer with a 150 mm integrating sphere (IS) detector. The IS detector is equipped with an internal cuvette holder so that absorbance measurements can be performed with the cuvette inside the IS. In addition, the spectrophotometer has a cuvette holder outside the IS for performing conventional absorbance measurements. It is shown that the fluorescence quantum yield can be obtained from a combination of absorbance measurements of the buffer and the analyte solution inside and outside the IS detector. Due to the simultaneous detection of incident and fluorescent photons, the absorbance measurements inside the IS need to be adjusted for the wavelength dependence of the photomultiplier detector and the wavelength dependence of the IS magnification factor. An estimate of the fluorescence emission spectrum is needed for proper application of the wavelength-dependent adjustments. Results are presented for fluorescein, quinine sulfate, myoglobin, rhodamine B and erythrosin B. The QY of fluorescein in 0.1 mol/L NaOH was determined as 0.90±0.02 where the uncertainty is equal to the standard deviation of three independent measurements. The method provides a convenient and rapid estimate of the fluorescence quantum yield. Refinements of the measurement model and the characteristics of the IS detector can in principle yield an accurate value of the absolute fluorescence quantum yield.     

罗丹明B的荧光猝灭法测定钢铁中微量钨

本文研究了在酸介质中,NaCl存在的条件下,罗丹明B与钨酸根WO_4~_(2-)络合生成三元络合物使罗丹明B试剂荧光猝灭。以365 nm为最大激发波长,测定594 nm最大发射荧光强度。用钠型Dowex50W—X4离子交换树脂胶柱交换分离溶液中共存的磷酸根、重铬酸根、Cr~(3+)、Fe~(3+)等干扰离子,利用罗丹明B荧光强度减弱的程度和钨含量呈线性关系,测定钢样中微量钨。