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利用一套CCD显微荧光图像观测和采集分析系统,分别在室 液氮温度下对半径为5μm发射波长0.65μm的InGaP半导体光学微盘的光图像进行了观测。 相似文献
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研制了不同厚度的直径为5-15μm的GaN光学微盘,并 学微盘的显微荧光图像进行了细致观测和数据值采集。结果表明,在同一个GaN外延样品上由于厚度的差别,微盘呈现两种不同类型的荧光图像, 相似文献
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使用时域有限差分法对近场耦合状态下的光学微腔进行了计算。系统地研究了微腔中不同阶径向模式的各方面性能的差异。并在此基础上讨论了通过改变耦合参数,选择性增强特定模式的途径。研究了数种非均匀介质微腔的性能改变,指出选择性增强特定模式,可以通过以下两类方法:一是对于均匀介质分布的微腔,通过改变耦合参数来改变修逝波场的场强和相位分布,例如改变入射波的入射角,改变耦合间距。二是通过区域性改变微腔的折射率分布来改变微腔的修逝波场的场强和相位分布,如折射率改变(△n)折射率梯度(dn/dr)。探讨选择性抑制高阶模形成改善微腔性能的途径。使得基模获得到高能量密度,和更低的模式体积为研究原子或离子与微腔的相互作用提供更好的环境。 相似文献
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设计并测试了两种基于微瓶腔结构的温度传感系统。分别基于电弧放电法和自主装法制备了氧化硅材料(SiO2)和紫外光固化胶(UCA)聚合物材料微瓶腔,通过锥形光纤耦合的方式分析了两种微瓶腔基本特性,并测试它们在温度传感中的应用。实验结果表明,SiO2微瓶腔在温度上升时的灵敏度为11.13 pm/℃,在温度下降时的灵敏度为10.25 pm/℃;UCA微瓶腔在温度上升时的灵敏度为111.89 pm/℃,在温度下降时的温度灵敏度为102.02 pm/℃。两者在上升和下降时均保持很好的一致性,尤其UCA微瓶腔温度灵敏度比SiO2微瓶腔提升了10倍。本文传感器具有体积小、价格低、可塑性和重复性好、灵敏度高等优势,在温度传感领域具有潜在应用。 相似文献
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本文对TiO2溶胶凝胶光学膜膜厚、折射率随不同温度作了在线测量,并讨论了在线温度对其光学性质的影响.考察了提拉速度对膜光学性质的影响。 相似文献
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半导体光学微腔—研究腔量子电动力学效应的绝妙范例 总被引:4,自引:0,他引:4
光学微腔中真空场和电子的行为与它们在自由空间中截然不同,导致了腔量子电动力学的一系列复杂性物理问题,半导体光学微腔是新一代凝聚态微型谐振器的典型代表,是探索腔量子电动力学,寻求新型微腔器及其应用的绝妙范例。文章概要介绍了几种典型的半导体光学微腔及其研究进展。 相似文献
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G. Annino M. Cassettari M. Fittipaldi M. Martinelli 《International Journal of Infrared and Millimeter Waves》2001,22(10):1485-1494
A whispering gallery resonator coupled to a dielectric waveguide is experimentally investigated around 86 GHz using a vectorial network analyzer. The resulting complex response function is compared with a theoretical model, simplified assuming negligible stationary waves; indeed their presence can be effectively compensated by a proper normalization procedure, made possible by a suitable analysis in the complex field. It is demonstrated that the proposed approach well reproduce the experimental results in a wide range of coupling conditions. Moreover, some outcomes of the model concerning the power flowing into the resonator are briefly discussed. 相似文献
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Giuseppe Annino Mario Cassettari Massimo Martinelli 《International Journal of Infrared and Millimeter Waves》2002,23(4):597-615
Several basic properties of homogeneous planar Whispering Gallery dielectric resonators are investigated through a general approach. In particular the values for the minimum and maximum allowed radius, defined by irradiation and dielectric losses, respectively, are obtained in terms of the complex dielectric constant of the involved media. The same approach is employed in the analysis of the limit allowed frequencies of a fixed family of mode, leading to the definition of the ideal frequency band. The role of the transverse mode is then discussed, and the effective frequency band is introduced and determined both in simple disc and circular ring resonators. The extension of the effective band is limited at least by a factor 3, in terms of decades, in comparison to the extension of the ideal one; this limitation, due to the presence of transverse modes, can be overcome using suitable designed nonhomogeneous resonators, as discussed in a following companion paper. 相似文献
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柱形微腔回音壁激光光谱模式的精确标定 总被引:3,自引:0,他引:3
由柱形微腔中回音壁模式满足的本征值方程,得到确定回音壁模式位置和间距的近似解析公式。以此近似解析公式,首次对直径在215~328 μm间的5个柱形微腔回音壁激光光谱做了模式标定。在用近似解析公式对柱形微腔激光光谱的数值作拟合的计算中,除了回音壁模的径向模式数(l)和角动量模式数(n)外无需其他拟合参数,解析公式的拟合值和实验激光光谱波长值间的偏差小于0.05 nm,拟合结果精确可靠。柱形微腔回音壁激光光谱模式的精确标定在模式的场分布计算以及频移型微腔生物传感器的研究应用中具有重要作用,文章介绍的方法亦可应用于柱形微腔直径和折射率的精密测量。 相似文献
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Giuseppe Annino Mario Cassettari Massimo Martinelli 《International Journal of Infrared and Millimeter Waves》2002,23(4):617-634
The basic theory underlying the realization of simple multiple-band non-homogeneous dielectric resonators, whose spectral response is the overlap of single-resonator frequency bands, is developed exploiting a general approach discussed in the previous companion paper. The limit frequencies of the proposed devices, given only by the dielectric properties of the involved materials, can differ in principle by several decades. Experimental confirmations have been obtained on a composite structure built up with teflon and polyethylene; as predicted by the theory, the overall band includes frequencies which range about from 20 GHz to more than 400 GHz, when high frequency resonances are selectively excited. The localization of the higher frequency radiation between the positive steps of the dielectric constant, which is the basic properties of these non-homogeneous resonators, has been experimentally verified by mapping the electromagnetic field intensity. Possible applications of multiple-band Whispering Gallery dielectric resonators are finally outlined. 相似文献
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光学微球腔因其回音壁模式可获得极高的品质因数而受到广泛关注.本文分析了Fabry-Perot腔和微球腔的基本原理,通过CO2激光熔融光纤实验制得了直径为1.2 mm的微球腔,并测试了微球腔和锥形光纤耦合结构的耦合特性.采用典型的PDH稳频系统设计了基于微球腔的稳频系统,分析了用于鉴频的误差曲线的吸收特性和色散特性,对比了不同调制频率、微球腔直径、耦合损耗、传输损耗下与误差曲线斜率的关系.结果表明:耦合状态下最大Q值可达到1.1×108,调节微球腔内横磁模和横电模的转换可优化耦合效率,匹配微球腔和锥形光纤的尺寸得到了径向二阶模式的透射谱,误差曲线效率达到15.4A mW/MHz.球腔在提高PDH稳频技术灵敏度上具有巨大潜力. 相似文献
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Venkata Ramanaiah Dantham Prem Ballabh Bisht Pramod Singh Dobal 《Journal of Raman spectroscopy : JRS》2011,42(6):1373-1378
Raman spectra and fluorescence of BaTiO3 and silica microspheres of different sizes have been studied. The observed whispering gallery modes (WGMs) have been assigned using theoretical simulations based on the Lorenz–Mie theory. The WGMs are found to have selective enhancements in the Raman spectra. The variations in the Raman spectra with the radial position of the excitation spot and excitation wavelength have been correlated with the morphology‐dependent internal field distributions of the microspheres. The effect of a thin dye coating on the fluorescence and Raman spectra was studied, and a coating thickness of ∼200 nm was estimated from the theoretical simulation of experimentally observed data based on the Aden and Kerker theory. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献