Raman spectra of synthetic sapphire

We have studied two samples of synthetic sapphire. Sample 1 was used as a window in a cryostat and was subjected to liquid nitrogen temperature for a long time (two years). Sample 2 was stored at room temperature. Under identical conditions, three types of Raman spectra were measured on Sample 1 in the wave number range 100–800 cm⁻¹. In the spectra from the central part of the sample, seven bands were observed, which are in good agreement with a spectrum of natural sapphire. In the spectra off the center, a subtle band was observed at a wave number of 724.6 cm⁻¹ which was related to the distribution of point defects. On the boundary of the sample, just a fluorescent background was measured. The measured Raman spectra resemble the spectra of γ-Al₂O₃ phase. On Sample 2, the spectra from the border were similar to those from the middle of the sample. The observed results indicate possible conversion of -Al₂O₃ into γ-Al₂O₃ due to prolonged exposure of synthetic sapphire to low temperatures.     

基于差分喇曼技术在抑制荧光中的应用研究

在传统的喇曼光谱检测过程中，喇曼光谱的有效信号有时会被荧光背景淹没，难以识别。为了准确、有效地分离差分信号和基线偏差，将差分喇曼技术和误差反向传播神经网络算法相结合，提出了差分喇曼解调和去噪算法，并进行了理论和实验验证。对市售的百草枯、补肾丸、机油以及海洛因等荧光较强的物质进行了检测分析。结果表明，可以得到有效的物质喇曼特征谱图。很好地解决了目前行业应用中检测的难题。     

萜类化合物的激光喇曼光谱

本文报导几种萜类化合物:α—蒎烯、β—蒎烯和茨烯的激光喇曼光谱。讨论了实验测得的喇曼谱线位移值与这些化合物分子结构的关系,其分析结果与化学方法确定的相一致。     

Raman spectra of hydrogen-treated optical fibres

Chemical reactions in a Ge-P-silicate optical fibre exposed to hydrogen at 100 bar and 150°C for times up to 120 h are studied by Raman spectroscopy. Hydride and hydroxyl groups are formed, as Si-H and P-OH. The reaction kinetics are consistent with a defect-related mechanism. The saturation concentration of hydroxyl is about 103 ppm.     

几种人工合成色素的荧光光谱与拉曼光谱研究

应用荧光光谱仪及微拉曼光谱仪分别对几种常见的人工合成色素溶液的荧光光谱和拉曼光谱进行了实验研究。一方面,首次测量其不同浓度合成色素溶液的荧光光谱,讨论其谱线特性。另一方面,以有致癌性的合成色素苋菜红为例,应用拉曼光谱技术进行定性和定量检测,验证拉曼光谱对色素检测的可行性。为了提高探测灵敏度,以55nm的金纳米粒子溶胶为基底,在785nm激发光下对不同浓度的苋菜红溶液进行了表面增强拉曼光谱探测,探测到的最低浓度为10-17mol/L。分析结果为这种色素的合理利用及安全快速检测提供了有效的光谱实验依据,也为其它色素的检测提供了参考方法。     

血清自体荧光—共振喇曼光谱的小波分析方法

本文在介绍激光透导血甭自体荧光－－共振喇曼光谱用于癌症诊断的物理学依据的基础上,详细过论了利用小波理论对激光诱导血清自体荧光－－共振喇曼光谱进行分析,撮用于癌症检测与分类特征的方法。     

TSCCC晶体的喇曼光谱研究

从金属-有机络合物中探索新的非线性光学材料是一项有科学意义和实用价值的研究工作.一水二氯硫代氨基脲合镉[Cd(NH_2CSNHNH_2)Cl_2·H_2O,简称TSCCC]晶体是在这一系列工作中发现的一种全新的、有实用前景的非线性光学晶体材料.它具有很强的非线性效应;在空气中不潮解、不风化;易生长出高质量单晶.本文首次报道TSCCC晶体的喇曼光谱,在各种几何配置下获得了该晶体的许多振动模.根据其结构和光谱间的关系,对其主要模作了初步认定.     

血卟啉衍生物分子的激光喇曼光谱

本文报道了用激光喇曼散射法测定三种血卟啉衍生物(HpD)样品的喇曼光谱.它们大多处在570～1640cm~(-1)之间.疗效不同的HpD的喇曼谱线位置有一定的差异,反映了卟啉环可能连接有不同的侧链;同一种HpD在不同溶剂中的谱线位置及强度不同,说明不同溶剂分子与样品分子有不同的作用.     

表面增强喇曼散射(SERS)光谱中物质吸附性质的研究

本文利用银电极表面吸附吡啶、硫氰酸根及其共存系统的SERS光谱的实验结果,对SERS光谱中吡啶和硫氰酸根的吸附性质作了初步研究。可以认为它们化学吸附于银电极表面。     

AlGaInP/GaInP多量子阱的拉曼光谱

利用LP-MOCVD生长了不同周期的AlGaInP／GaInPMQW样品，并测量了它们的拉曼光谱。由于样品包括了掺杂的电流扩展层和欧姆接触层以及上、下限制层，拉曼光谱中观察到了与掺杂有关的耦合电子(空穴)气-纵光学声子模。根据喇曼光谱的选择定则，结合光致发光谱，发现AIP-LO／TO的相对强度比可以评定晶体AlGaInP MQW的生长质量。     

Raman spectra of the laser-irradiated GaSe single crystals

The specific features of the crystal structure of the lamellar GaSe crystals of various polytypes are analyzed. The possibility of identifying the phase transitions, which occur as a result of variations in temperature, pressure, and composition, is considered from the standpoint of resonance Raman scattering. The effects of high-temperature thermal annealing and pulsed laser irradiation on Raman spectra is investigated. It is found that pulsed laser radiation gives rise to regions with different polytype composition and regions with residual stress.     

五硼酸钾晶体喇曼谱的研究

本文报道了紫外倍频晶体五硼酸钾的激光喇曼光谱,给出了各配置下的各振动模,并讨论了喇曼谱与结构的关系。     

用于易燃易爆危险化学品快速识别的手机拉曼系统

危险化学品泄漏,公共场所爆炸等安全问题时刻威胁公众安全,亟需研究用于危化品现场检测的便携、快速、准确的探测装置。虽然现有的检测装置能够实现对样品的识别,但由于体积大,需要预处理,不适合现场快检。因此,提出了将拉曼系统与手机融合,使其更加便捷,便于实现对危险化学品的现场快速识别。该仪器采用了大数值孔径镜头（F/2.0）替换传统反射光谱仪中凹面反射镜（F/4.0）,光学收集效率提高了近4倍,同时利用体相位全息光栅和狭缝空间耦合技术,提高了系统的灵敏度。文中利用设计的拉曼系统对10种易燃易爆危险化学样品进行光谱测试,实现了对危化品的现场检测,10种危化品与数据库的匹配系数能达到95%以上,具有快速、准确、无损的优势,对日后的安检应用领域具有重要意义。     

Detection of skin cancer by classification of Raman spectra

Skin lesion classification based on in vitro Raman spectroscopy is approached using a nonlinear neural network classifier. The classification framework is probabilistic and highly automated. The framework includes a feature extraction for Raman spectra and a fully adaptive and robust feedforward neural network classifier. Moreover, classification rules learned by the neural network may be extracted and evaluated for reproducibility, making it possible to explain the class assignment. The classification performance for the present data set, involving 222 cases and five lesion types, was 80.5%+/-5.3% correct classification of malignant melanoma, which is similar to that of trained dermatologists based on visual inspection. The skin cancer basal cell carcinoma has a classification rate of 95.8%+/-2.7%, which is excellent. The overall classification rate of skin lesions is 94.8%+/-3.0%. Spectral regions, which are important for network classification, are demonstrated to reproduce. Small distinctive bands in the spectrum, corresponding to specific lipids and proteins, are shown to hold the discriminating information which the network uses to diagnose skin lesions.     

Raman spectra of CdTe/ZnTe self-assembled quantum dots

In this paper, we present Raman scattered spectra and results of photoluminescence (PL) measurements of CdTe/ZnTe self-assembled quantum dots (SAQD). The PL spectrum displayed two main emission peaks, both connected with the existing of QDs. One presents direct deexcitation to ground state and the other is optical phonon (ω=204.2 cm^?1)-assisted deexcitation. The registered multiphonon (MP) emission process depends on temperature. At low temperature, one-phonon spectra shows line at 200.4 and 210.3 cm^?1 (ZnTe LO mode confined by degenerate superlattices), 217 cm^?1 (TA+LO in ZnTe) and 386 cm^?1 (LO+TO(Γ) in ZnTe).     

拉曼光纤放大器在国内工程中的应用

重点介绍了拉曼光纤放大器在长跨距SDH线路中的应用、产品设计中需要考虑和解决的问题；探讨了超长跨距SDH光传输系统的实现方案和测试结果。同时讨论了拉曼光纤放大器在实际线路应用中需要注意的问题，首次给出了拉曼光纤放大器在国内2．5Gbit／s系统200km G.652光纤上的现场应用结果。     

Raman spectra of GaPAs–GaP heterostructure waveguides

A GaPAs waveguide with GaP cladding layers, has been fabricated in only two steps of LPE growth. One-way optical loss of the fabricated GaPAs–GaP waveguide is 12% mm⁻¹ (α=1.9 cm⁻¹). The free carrier concentration of the GaPAs layer is 1×10¹⁶ cm⁻³ (α=0.05 cm⁻¹). The backward spontaneous Raman spectrum from the GaPAs waveguide shows a GaP-like longitudinal optical (LO) phonon line. The LO band is intensified and shifted to a higher frequency compared to the LO phonon of GaP bulk crystal.     

食用植物油的激光喇曼光谱研究

用激光喇曼光谱方法测量和研究了食用植物油中某些分子基团的振动谱线,观察到了不饱和脂肪酸中的C＝C双键的振动喇曼谱线在油被长时间加热后减弱的现象。     

A method to predict the Raman gain spectra of germanosilicatefibers with arbitrary index profiles

In this letter, we present a technique for calculating the Raman gain spectra of germanosilicate fibers from their index profiles. The gain spectra depend on radial profiles of the guided optical modes and the glass composition, in particular the distribution of Si-O-Si and Ge-O-Si bridging bonds. We have obtained spectral coefficients, which represent the contributions from these bonds using Raman gain measurements made on a set of calibration fibers with well-characterized index profiles. We describe how these spectral coefficients can be used in the design of Raman gain fibers, and we demonstrate the accuracy of our technique over a broad range of fiber types     

Infrared reflectance spectra and Raman spectra of CuxAg1−x GaS2 solid solutions

Using crystals of the compounds CuGaS₂ and AgGaS₂ and solid solutions based on them, the IR reflectance spectra and the Raman spectra have been studied in polarized light. Values have been determined for the frequencies of the longitudinal and transverse optical phonons, the damping coefficients, the IR intensity, and ɛ ₀, and ɛ _∞. The concentration dependences of the indicated parameters have been constructed, and the character of the behavior of the optical vibrations in the solid solutions has been established. Fiz. Tekh. Poluprovodn. 32, 684–687 (June 1998)