首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到16条相似文献,搜索用时 93 毫秒
1.
近场拉曼光谱技术的发展   总被引:1,自引:0,他引:1  
吴晓斌  王佳 《光学技术》2004,30(4):425-430
将近场光学技术与拉曼光谱相结合,发展出近场拉曼光谱术。综述了近场拉曼光谱探测技术的发展现状,讨论了近场拉曼光谱术的优点和纳米局域光谱分析能力。对两种常用的探测方法(常规近场光谱探测方法和近场增强拉曼光谱探测方法)进行了比较,并介绍了近场拉曼光谱技术在生物、化学、纳米材料等领域的一些应用。  相似文献   

2.
基于有孔探针SNOM的近场拉曼光谱和成像技术的出现使得拉曼光谱的分辨率突破了光学衍射极限,从而提供了一个有力的工具对样品亚波长尺度之下的化学信息进行表征。文章讨论了探针性质对实现近场拉曼光谱的影响,并全面地介绍了有孔探针近场拉曼光谱发展十余年来在纳米尺度化学分辨成像、液-液界面性质研究、微观层面解释SERS增强机理、图像化反映SERS热点分布等诸多领域的研究进展。  相似文献   

3.
单壁碳纳米管束针尖增强近场拉曼光谱探测实验研究   总被引:2,自引:0,他引:2  
针尖增强近场拉曼光谱术是最近发展起来的光谱技术.金属探针在获得样品纳米局域表面形貌的同时,受激光激发,在针尖附近产生增强电磁场,得到与形貌位置精确对应的针尖增强局域拉曼光谱,形貌和光谱的结合实现了纳米局域的光谱指认.文章建立了一套针尖增强近场拉曼光谱测龋装置,并用此装置对电弧法合成的单壁碳纳米管进行了近场拉曼光谱探测.测量了直径为100 nm单壁碳纳米管束的针尖增强拉曼光谱,进一步得到至多3根单壁碳纳米管的近场拉曼光谱,实现了超衍射分辨光谱探测.通过与远场拉曼光谱比较发现,针尖增强近场拉曼光谱的增强因子大于230倍.实验证明,同时具有超衍射空间分辨和拉曼光谱信号增强能力的针尖增强近场拉曼光谱术将是纳米材料和纳米结构表征的一种重要方法.  相似文献   

4.
朱若剑  王佳  金国藩 《光学技术》2002,28(6):515-517
传统光学引入了远场衍射的尺度极限。自从提出了近场光学技术以来 ,由于近场扫描光学显微镜 (NSOM)系统的复杂性而使得近扬的引入和利用变得困难。具有多层纳米薄膜结构的超分辨近场结构 (Super RENS)的提出改变了这种局面 ,并在诸如超高密度光学数据存储、近场光刻技术、纳米光子学晶体管等领域获得了重要的应用。围绕Su per RENS技术 ,通过综述它的基本原理、物理机制以及各项应用 ,指出了基于近场激发与增强原理的新型多层纳米薄膜结构在未来非线性光学器件上的应用与发展前景  相似文献   

5.
超分辨近场结构(super-resolution near-field structure,super-RENS)由于突破了传统远场光学衍射极限的限制,在纳米光储存、微纳米加工、基于局域表面等离子体增强的生物传感器方面展现出良好的应用前景,因此吸引了众多研究者的目光.文章简要介绍了超分辨近场结构的发展历程、相应的工作机理、最新研究动态及其在超高密度光存储、近场光刻中的应用状况,并对未来的工作重点做出展望.  相似文献   

6.
近场光学技术在高分辨率成像、光谱探测和纳米加工等领域有广泛应用,而光纤探针是其中一个关键部件.如何提高光纤探针的传输效率是近场光学技术应用中的一个重要问题.本文采用三维时域有限差分方法,计算了锥形有孔探针的传输效率,分析了锥角、针尖孔径、波长和金属层厚度等因素对光纤探针传输效率的影响,并比较了裸光纤探针和有金属涂层的光...  相似文献   

7.
近场光学显微技术   总被引:4,自引:2,他引:2       下载免费PDF全文
王海潼  刘斐 《应用光学》2005,26(3):36-40
本文在介绍近场光学显微镜原理的基础上,对近场光学显微技术进行了一定深度的探讨,并着重研究了纳米级探针的制作和纳米级样品与探针间距的控制这两个近场光学显微技术中的关键问题,说明了近场光学显微探针的工作方式,阐述了近场光学成像的衬度类型,介绍了近场光学显微技术在多个领域的应用。在参考大量国内外最新研究成果的基础上,提出了一些个人的见解。  相似文献   

8.
近场光学是指当光探测器及探测器-样品间距均小于辐射波长条件下的光学现象.利用近场光学扫描显微镜和近场光谱仪,不但能够以突破衍射极限的超高分辨率在纳米尺度实现光学成像,而且还可获得纳米微区的光谱信息.文章介绍近场光学的原理及其在凝聚态物理领域中的应用与进展,并给出了我们的初步结果  相似文献   

9.
SNOM应用于光电材料和器件的光学特性的探测和表征   总被引:2,自引:0,他引:2  
王佳  徐铁军 《光学技术》2002,28(5):412-418
介绍了近场光学及近场探测的原理 ,给出了其用于光电器件研究中的一些结果。近场光学方法具有超衍射分辩的本领和纳米局域光场探测的能力 ,适用于多种光电材料的探测与表征 ,包括 :LD、光纤波导器件、光子晶体器件等。纳米局域光场和倏逝场的探测发现了许多远场探测无法得到的结果 ,为光电器件纳米结构的研究提供了有力证据  相似文献   

10.
通过热蒸发方法成功制备出SdS0.65Se0.35纳米带,得到的纳米带表面光滑,宽度厚度均一,表现出很高的结晶质量.使用近场光学显微镜对纳米带室温下的带边荧光波导和光致荧光近场光谱进行研究.发现SdS0.65Se0.35纳米带呈现良好的光波导的特性;同时通过近场光学显微镜得到的空间分辨光谱,发现随着传播距离的增大,纳米带的光致荧光光谱有持续的红移现象.这种光谱红移现象是带间跃迁过程中带尾态的吸收效应引起的,并作了光谱带尾态吸收的理论模拟与实验结果进行比较.光波导传输过程中光谱的变化反映了信息在整个传导过程中的情况,体现了信息传递过程中的稳定性和有效性.三元合金材料SdS0.65Se0.35纳米带的波导和光谱性质研究,对于其他组分可调的三元合金纳米结构的制备和研究,及发展新型的纳米功能器件有重要意义.  相似文献   

11.
反射式无孔径近场Raman研究(英文)   总被引:1,自引:0,他引:1  
近场扫描光学显微技术与Raman光谱技术的结合能够在纳米尺度下提供化学 /结构信息 ,这对很多应用都是至关重要的 ,比如硅器件 ,纳米器件 ,量子点及生物样品单分子研究。本文报导了采用无孔径探针的近场Raman研究。我们的系统有两大特征 :1 近场Raman的增强是通过金属探针上的银镀层实现的 ,无需样品准备 ;2 系统在反射模式下工作 ,适用于任何样品。这两点对实际应用是至关重要的。我们首次在实际硅器件上用 1秒积分时间获得了 1维近场Raman映射和 2维近场Raman图象。我们首次展示了由于积分时间短 ,该技术可用于成象用途。因此 ,这是近场扫描Raman研究中的一次巨大进步。此外 ,我们系统中采用的金属探针可同时用于AFM及电学特性成象 ,比如电阻 ,电容 ,这些是器件应用中的重要参数。  相似文献   

12.
The structure of our material world is characterized by a large hierarchy of length scales that determines material properties and functions. Increasing spatial resolution in optical imaging and spectroscopy has been a long standing desire, to provide access, in particular, to mesoscopic phenomena associated with phase separation, order, and intrinsic and extrinsic structural inhomogeneities. A general concept for the combination of optical spectroscopy with scanning probe microscopy emerged recently, extending the spatial resolution of optical imaging far beyond the diffraction limit. The optical antenna properties of a scanning probe tip and the local near-field coupling between its apex and a sample provide few-nanometer optical spatial resolution. With imaging mechanisms largely independent of wavelength, this concept is compatible with essentially any form of optical spectroscopy, including nonlinear and ultrafast techniques, over a wide frequency range from the terahertz to the extreme ultraviolet. The past 10 years have seen a rapid development of this nano-optical imaging technique, known as tip-enhanced or scattering-scanning near-field optical microscopy (s-SNOM). Its applicability has been demonstrated for the nano-scale investigation of a wide range of materials including biomolecular, polymer, plasmonic, semiconductor, and dielectric systems.

We provide a general review of the development, fundamental imaging mechanisms, and different implementations of s-SNOM, and discuss its potential for providing nanoscale spectroscopic including femtosecond spatio-temporal information. We discuss possible near-field spectroscopic implementations, with contrast based on the metallic infrared Drude response, nano-scale impedance, infrared and Raman vibrational spectroscopy, phonon Raman nano-crystallography, and nonlinear optics to identify nanoscale phase separation (PS), strain, and ferroic order. With regard to applications, we focus on correlated and low-dimensional materials as examples that benefit, in particular, from the unique applicability of s-SNOM under variable and cryogenic temperatures, nearly arbitrary atmospheric conditions, controlled sample strain, and large electric and magnetic fields and currents. For example, in transition metal oxides, topological insulators, and graphene, unusual electronic, optical, magnetic, or mechanical properties emerge, such as colossal magneto-resistance (CMR), metal–insulator transitions (MITs), high-T C superconductivity, multiferroicity, and plasmon and phonon polaritons, with associated rich phase diagrams that are typically very sensitive to the above conditions. The interaction of charge, spin, orbital, and lattice degrees of freedom in correlated electron materials leads to frustration and degenerate ground states, with spatial PS over many orders of length scale. We discuss how the optical near-field response in s-SNOM allows for the systematic real space probing of multiple order parameters simultaneously under a wide range of internal and external stimuli (strain, magnetic field, photo-doping, etc.) by coupling directly to electronic, spin, phonon, optical, and polariton resonances in materials. In conclusion, we provide a perspective on the future extension of s-SNOM for multi-modal imaging with simultaneous nanometer spatial and femtosecond temporal resolution.  相似文献   

13.
We present near-field Raman spectroscopy and imaging of single isolated single-walled carbon nanotubes with a spatial resolution of approximately 25 nm. The near-field origin of the image contrast is confirmed by the measured dependence of the Raman scattering signal on tip-sample distance and the unique polarization properties. The method is used to study local variations in the Raman spectrum along a single single-walled carbon nanotube.  相似文献   

14.
《Comptes Rendus Physique》2012,13(8):837-852
We show, through several selected case studies, the potential benefits that can be obtained by controlling the polarization states of the exciting and scattered radiations in a Raman scattering experiment. When coupled with polarization control, Raman spectroscopy is thus capable of providing extra information on the structural properties of the materials under investigation. The experimental examples presented in this work are taken from the area of both conventional, i.e., far-field, as well as from near-field Raman spectroscopy. They cover topics such as the stress tensor measurement in strained semiconductor structures, the vibration mode assignment in pentacene thin films and the Raman scattering tensor determination from near-field measurements on azobenzene monolayers. The basic theory necessary for modelling the far- and near-field polarized Raman responses is also given and the model efficiency is illustrated on the experimental data.  相似文献   

15.
Using both analytical and numerical methods to study transmission of light through dielectric-filled subwavelength apertures in a real metal, we have found that a propagating mode can in principle exist inside a waveguide of arbitrary small size if a particular relationship between the dielectric constants of the cladding and filling materials at the incident frequency is satisfied. Practical transmission through a subwavelength aperture of finite depth can be enhanced when the depth is such that Fabry-Pérot-like resonances are excited. For 810 nm light incident on a silicon-filled 50-nm-diameter aperture in a 200-nm-thick gold film, we found that a normalized near-field intensity ratio of 1.6 at the exit can be achieved. This resonantly enhanced transmission phenomenon may be advantageously applicable to near-field scanning optical microscopy and single-molecule spectroscopy.  相似文献   

16.
An exact analytical solution of the self-consistent equation for the local field is used to calculate the near-field optical images of pyramid-like nano-objects placed at a surface of a solid. The diagram method developed previously for near-field image formation is generalized in order to describe layered objects, which are treated as many-body systems. The near-field optical images of triangular and square pyramids are calculated for the illumination configuration as well as those of triangular and square prisms. It is found that the near-field images of nanoparticles having the dielectric constant close to that of the substrate change rapidly and in a complicated manner with the probe–sample distance.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号