A Fully Vectorial Effective Index Method for Accurate Dispersion Calculation of Photonic Crystal Fibres

A fully vectorial effective index method is developed for accurate dispersion calculation of photonic crystal fibres （PCFs）. In order to improve the accuracy of the model, different values for the effective core radius are used when PCFs have different fibre parameters. The accuracy of our approach is demonstrated by comparing our results with other numerical and experimental results reported in literature. It is found that the accuracy of the fully vectorial effective index method is improved and our results agree well with accurate numerical results obtained by other methods as well as the previously reported experimental data.     

聚甲基丙烯酸甲酯掺杂Ce3+的飞秒激光三维信息存储

用飞秒激光(200 fs,1 kHz,800 nm)脉冲在掺杂稀土离子Ce3 的聚甲基丙烯酸甲酯(PMMA)膜中进行了光存储实验研究,包括对样品的吸收光谱、激光照射前后的电子旋转共振(Electron spin resonance,ESR)光谱的测量和讨论。结果表明掺杂稀土离子Ce3 的聚甲基丙烯酸甲酯膜具有较低的写入阈值,有利于高速、并行的三维光存储。实验结果采用传统光学显微镜并行读出。给出了四层存储结果(点间距和层间距分别是4μm和16μm),并讨论了脉冲能量的大小对空腔尺寸的影响,进行高密度存储时,在保证读出信号灰度值足够大的情况下,应选择尽量小的激光脉冲写入能量。实验结果表明这种材料可以应用于三维光信息存储。     

Kerr介质中级联三能级原子与压缩相干态相互作用的光子统计演化

本文研究了存在Kerr介质的高Q腔中压缩相干态与级联三能级原子相互作用的光子统计演化规律,讨论了光场参数、Kerr介质及相干振幅对平均光子数的影响.     

含吩噻嗪金属配合物的合成及非线性光学性质研究

本文报道了一种新的配体:10-乙基-3-甲酰吩噻嗪缩肼基二硫代甲酸甲酯(HL)及其金属配合物的合成。采用了元素分析、质谱、核磁共振、红外光谱对配体及其金属配合物进行了表征。此外,并应用紫外、荧光和Z-扫描技术,测定了配体及其金属配合物的荧光最佳发射波长(λ_max^em)、荧光量子产率(Φ_f)、寿命(τ)和非线性光学性质。结果表明它们在DMF溶液中都能发射出较强的橄榄色荧光,配体及其金属配合物都有双光子吸收,并且金属配合物的非线性光学效应比配体明显增强。用半经验量子化学方法(RHF/PM3)计算结果与实验值较为吻合。     

含铅聚合物微凝胶与硫化氢反应前后在良溶剂中的分子扩散行为

用溶液聚合法制备出轻度交联的含铅微凝胶,用光子相关光谱技术测定其在良溶剂中与H2S反应前、后的扩散行为,由外推法得到在浓度无限稀时的分子扩散系数,给出微凝胶的流体力学半径。结果表明:相同量的含铅微凝胶在不同的初始浓度下与H2S反应,生成含PbS纳米微粒的凝胶；但其体积增大不同,这说明H2S与含铅微凝胶的反应既可以在分子内也可以在分子间进行,分子间的反应使含硫化铅微凝胶扩散系数随浓度的变化曲线的线性范围变小。     

聚苯乙烯乳胶球三维有序体的制备及其显微形貌表征

A three-dimensional (3D) ordered structure was achieved by self-organization of monodisperse polystyrene latex about 250nm in diameter after being ambient dried. The stacked morphology was investigated by scanning electron microscopy(SEM) observation. It is shown that the face-centered cubic(FCC) phase dominantly exists. This finding presents a potential template for preparing an inverse FCC structure as a photonic crystal of full band gap if the index contrast is higher than 2.8.     

Synthesis, Characterization and Two-Photon Absorption Properties of a Novel Pyridinium Salt

A novel pyridinium salt, 2,4-bis[p-(N,N-dimethylamino)styryll-N-metlayl pyridinium iodide (BMSPI) was synthesized and characterized by TG, ^1H NMR spectroscopy and elemental analysis, and the reaction process was studied by using ES-MS. When BMSPI was pumped by a pulsed 1064 nm, 50 ps laser beam, it manifests highly efficient TPA (Two-Photon Absorption) and up-conversion superradiance. The up-conversion efficiency was 6.0% at the pump energy of 4-6 mJ and the lifetime of two-photon fluorescence was measured as 59 ps.     

多光子技术及其应用研究进展

本文综述了多光子技术的基本原理及其在生命科学、化学、物理和材料科学领域的应用研究进展。     

OCS分子的共振多光子电离光谱

OCS分子的真空紫外吸收光谱早有研究,但有关OCS分子的多光子电离光谱尚未见报导。我们利用可调脉冲激光器,研究了OCS分子的共振多光子电离光谱。首次观察到OCS分子在277—285nm波长范围内的多光子电离光谱。OCS由硫氰酸铵和硫酸反应制取,经多次低温蒸馏纯化。产物通过FT-IR红外光谱和     

[Me3NC2H4OH]Zn2Cl5水溶液的激光光解研究

利用时间分辨激光光解技术研究了季铵盐型离子液体[Me₃NC₂H₄OH]Zn₂Cl₅(简写R-Zn₂Cl₅)的光解行为, 研究发现离子液体能被266 nm激光单光子电离, 生成阳离子自由基、[Zn₂Cl₅]^•中性自由基和水合电子, 观察到胆碱激发三线态的存在, 并测定了离子液体光电离的量子产额为0.04. 利用266 nm激光对离子液体、胆碱、氯化锌、氯化钠的光解行为比较, 发现胆碱阳离子的贡献很小, [Zn₂Cl₅]^－阴离子起主要作用. 采用氧化性自由基SO₄^•－引发离子自由基, 揭示其光电离机理, 测定离子液体的动力学反应速率常数, SO₄^•－ 460 nm的衰减速率常数为1.3×10⁹ L•mol^－1•s^－1, 320 nm离子自由基瞬态产物的生成速率常数为1.5×10⁹ L•mol^－1•s^－1, 两者很接近, 说明SO₄^•－自由基的衰减与瞬态自由基的生成是同步的.