共查询到20条相似文献,搜索用时 15 毫秒
1.
A. Dzarova F. Royer D. Jamon P. KopcanskyF. Choueikani H. GojzewskiJ.J. Rousseau M. Timko 《Journal of magnetism and magnetic materials》2011,323(10):1364-1367
The anisotropy of several PVA/magnetosome magnetically textured films has been investigated. The thin film synthesized under the influence of a magnetic field (99 mT) shows the typical behavior of an anisotropic material. The results show that the magnetic field applied during the synthesis promotes an orientation of the chains of magnetosomes and permanent textured film is obtained after solidification. 相似文献
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G. A. Puchkovskaya A. G. Tereshchenko L. I. Shanskii O. V. Yaroshchuk 《Journal of Applied Spectroscopy》1998,65(1):124-129
The process of optical anisotropy indiction in azopolymer films upon irradiation by polarized UV light is studied by means
of UV and IR birefringence spectroscopy. A substantial dependence of the character of the relaxation of the induced anisotropy
on the exposure time to the exciting light is revealed: whereas the process of anisotropy induction is reversible at small
exposure times, at large exposure times the induced anisotropy virtually does not relax and even increases after the irradiation
is terminated. A difference between kinetic curves of dichroism and birefringence induction is shown: at exposure times corresponding
to the saturation of the induced dichroism a slow increase in the birefringence curve is observed. Results obtained are explained
in terms of the assumption of partial ordering of macrochain fragments in irradiated films. The assumption is substantiated
by measurements of polarized IR spectra.
Institute of Physics of the National Academy of Sciences of Ukraine, 46, Nauka Ave., Kiev, 252650, Ukraine. Translated from
Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 121–125, January–February, 1998. 相似文献
3.
A new type of phase-shifting interferometer was presented by rotating an azo-polymer film with photo-induced optical anisotropy in the light path of orthogonal polarization interferometry. By changing the angle of the optical axis of the azo-polymer film, four phase-shifted fringe patterns were obtained, from which phase difference between orthogonal polarized light could be calculated. The polarization states and the formation of the interferograms were analyzed theoretically using Jones matrix calculations and the experimental verification of the proposed method was also given. This method has a simple optical configuration which utilizes commercially available polarization devices and anisotropic azo-polymer film of low cost. The phase-shifting interferometer also demonstrates a new application of azo-polymer film. 相似文献
4.
All optical switching in azo-polymer planar waveguide 总被引:1,自引:0,他引:1
In this paper all optical switching in planar methyl red doped poly (methyl methacrylate) (MR/PMMA) waveguide and the effects of different parameters on this process are presented. Switching was achieved by a 488 nm Ar ion laser (pump beam) on a 633 nm He-Ne laser (probe beam) when passed through the waveguide. The effect of temperature and pump intensity, polarization and chopping frequency on switching is investigated. The switching process is attributed to trans-cis-trans photoisomerization of azo dyes in the polymer host. By studying the absorption spectrum of the sample, it is shown that both pump and probe laser beams are effective on the switching process. 相似文献
5.
《Current Applied Physics》2018,18(11):1196-1200
We have experimentally demonstrated circular polarization generation from linear polarized soft X-ray at synchrotron by adopting a thin magnetic film polarizer. Polarizer is composed of Co/Pt multilayer with a perpendicular magnetic anisotropy, which allows us to easily accommodate without needing any tilting angle into the measurement setup since the circular polarization is generated for the X-ray with normal incidence and transmission. Generated circular polarization is examined by observing magnetic domain features based on the X-ray magnetic circular dichroism, where ∼11% of circular component is estimated compared to the case of full circular polarization. 相似文献
6.
Zhusong He Yundong Zhang Hao Wu Ping Yuan Shuangqiang Liu 《Optics Communications》2009,282(23):4548-4551
An atomic optical filter based on optical anisotropy induced by another left-circularly polarized pump field is theoretically and experimentally investigated in the 5S1/2–5P3/2–5D3/2 ladder-type system of rubidium vapor. The filter displays a single peak transmission of 14.4% with 396 MHz bandwidth narrower than Doppler width. Furthermore, the variation of peak transmission versus pump intensity, pump detuning and cell temperature are also given. The theoretical and experimental results are in good agreement, which can enhance understanding of operation mechanism for this category of filter. The narrow-bandwidth filter is useful for free-space optical systems and laser spectroscopy. 相似文献
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Time-resolved polarization-dependent fluorescence of Cybesin in solution and in cancerous and normal prostate tissues were measured. The polarization preservation property of Cybesin in tissue was observed. The fluorescence intensity emitted from a Cybesin-stained cancerous tissue area was found to be much stronger than that from a Cybesin-stained normal tissue area indicating that cancerous prostate tissue takes-up more Cybesin than normal tissue. The polarization anisotropy of Cybesin contained in cancerous prostate tissue was found to be larger than that of Cybesin in normal prostate tissue indicating that a larger degree of polarization was preserved in the Cybesin-stained cancerous tissue due to structures. A static anisotropy component from the emission of cell-bonded Cybesin molecules in tissue and a time-dependent anisotropy component from the emission of un-bonded Cybesin molecules were determined and discussed. The static anisotropy value of Cybesin in stained cancerous tissue was found to be much larger than that in stained normal tissue. The fluorescence polarization difference imaging technique based on the polarization preservation of Cybesin was used to enhance the image contrast between cancerous and normal prostate tissue areas. 相似文献
11.
Sheng-Hui Chen Kai Wu Chien-Cheng Kuo Sheng-Ju Ma Cheng-Chung Lee 《Optical Review》2009,16(4):479-482
A new method based on the polarization interferometer structure has been applied to measure the optical admittance, the refractive
index and thickness of a thin film. The structure is a vibration insensitive optical system. There is one Twyman-Green interferometer
part to induce a phase difference and one Fizeau interferometer part to induce the interference in the system. The intensities
coming from four different polarizers were measured at the same time to prevent mechanical vibration influence. Using the
polarization interferometer, the optical admittance, the refractive index and thickness of a single layer of Ta2O5 thin film has been measured. The measurement results were compared with the results obtained by ellipsometer. The results
meet reasonable values in both refractive index and thickness. 相似文献
12.
感应耦合等离子体刻蚀在聚合物光波导制作中的应用 总被引:1,自引:0,他引:1
提出了利用感应耦合等离子体(ICP)刻蚀技术提高聚合物光波导器件性能的方法,介绍了ICP刻蚀技术的原理和优点。选取聚甲基丙烯酸甲酯-甲基丙烯酸环氧丙酯(P(MMA-GMA))作为波导材料,采用氧气作为刻蚀气体,研究了ICP参数变化对刻蚀效果的影响。介绍了倒脊形光波导的制备过程,采用改变单一工艺参数的方法,分析了刻蚀效果随时间、功率、压强、气体流量等参数的变化,对参数优化后刻蚀得到的凹槽和平板结构进行了表征。实验结果表明:在天线射频功率为300 W,偏置射频功率为30 W,气体压强为0.5 Pa,氧气流速为50 cm3/min的条件下,可获得侧壁陡直、底面平整的P(MMA-GMA)凹槽结构。 相似文献
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数值研究了各向异性光反馈注入的垂直表面发射激光器(VCSEL)的矢量偏振模转换机理,研究结果表明,首先,当注入电流接近阈值电流时,由VCSEL的外部参数和偏振器控制的光反馈注入量中各偏振模的能量决定VCSEL 输出的偏振态.其次,由偏振器控制的各向异性光反馈注入引起的VCSEL输出偏振态呈周期性变化.另外,当由偏振器控制的反馈注入量中的x^偏振和y^偏振模能量相当时, x^偏振模和y^偏振模之间竞争激烈,而激光器外部微小的扰动都会打破这两种偏振模竞争
关键词:
各向异性光反馈
垂直表面发射激光器
矢量偏振模 相似文献
16.
半花菁衍生物LB膜的非线性光学性能研究 总被引:3,自引:1,他引:2
本文利用二次谐波产生、紫外-可见吸收光谱、Ⅱ-A曲线等方法,探讨了四种分子结构相近的半花菁染料衍生物LB膜的非线性光学性能。研究了它们的分子结构与β值大小的关系,分析了引起β值变化的主要原因,证实了极性基团的强弱顺序。并讨论了LB膜中聚集效应程度不同的原因。通过光学二次谐波信号强度与膜层数的关系,对比了样品的成膜性能。 相似文献
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以新型光学聚合物Topas 环烯烃共聚物(折射率为1.53)为基质,设计了四种微结构聚合物光纤.应用有限元方法对各种光纤在波长0.5—2.0 μm范围内的基模有效折射率、模场面积和数值孔径进行了计算.研究了结构参数对模场分布、单模特性和色散特性的影响.得出了具有极大/小模场面积、无限单模传输和平坦近零色散的光纤结构参数.与石英、聚甲基丙烯酸甲酯基质的微结构光纤相比,该光纤具有更大的数值孔径和较宽的平坦近零色散范围.为光纤的制备提供了理论指导.
关键词:
微结构聚合物光纤
有限元方法
传输特性
Topas 环烯烃共聚物 相似文献
18.
本文介绍了一种确定聚合物太阳能电池功能层光学常数和厚度的方法. 该方法借助于特定的色散模型拟合透射率测试曲线以获得功能层光学常数和厚度值. 文中比较了Forouhi-Bloomer和Lorentz-Oscillator模型在体异质结薄膜的透射率拟合计算中的适用性, 计算了poly(3-hexylthiophene)(P3HT)/[6,6]-phenylC61-butyric acid methyl ester (PCBM)和 poly[2-methoxy-5-5(2'-ethyl-hexyloxy)-1,4-phenylenevinylene](MEH-PPV)/PCBM体异质结薄膜的光学常数和厚度. 拟合得到的曲线与实验曲线符合良好, 厚度计算的结果与台阶仪测量结果保持一致, 误差小于4%. 进一步分析得到的热退火和加入高沸点溶剂添加剂后P3HT/PCBM薄膜的光学常数和光学禁带值与相应器件伏安特性相符. 该方法适用于所有体异质结的功能层, 可用于聚合物太阳能电池的膜系优化和在线检测. 相似文献
19.
An increase in the concentration of photochromic N,N′-diacetyl indigo in glass-like poly(methyl metacrylate) within the range
of 0.1–0.5 mol.% is accompanied by a decrease in the rate constant of thermoisomerization of the photoinduced form, which
is explained by the formation of molecular assemblies that change the properties of the medium. A threefold plus increase
in thermoisomerization of the photochromic compound in samples with a high concentration has been revealed with an increasing
duration of photoirradiation. The phenomenon can be used in optical image processing, e.g., contrast inversion.
Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 4, pp. 494–498, July–August, 1997. 相似文献
20.
Soft magnetism and magnetic anisotropy properties of CoZrNb thin films deposited on polyethylene terephthalate (PET) substrate by magnetron sputtering were investigated. As the film thickness increases, the coercivity of films decreases from 7 to 4 Oe. It exhibits an in-plane uniaxial magnetic anisotropy as the thickness of CoZrNb thin films increases. An easy axis is observed in CoZrNb films along the direction transverse to the rolling direction of the polymer web. 相似文献