共查询到20条相似文献,搜索用时 15 毫秒
1.
Kenichiro Tanaka Kazuhito Tsukagoshi Yoshinobu Aoyagi Shinji Kuroda Kôki Takita 《Optical Review》2006,13(4):276-278
We have developed a magnetic-field-type scanning near-field optical microscopy (SNOM) system, which enables us to obtain two-dimensional
near-field images under magnetic fields up to 4 T. We have performed two-dimensional near-field scanning optical spectroscopy
on (Cd,Mn) Te self-assembled quantum dots with this system. 相似文献
2.
Influence of the probe--sample interaction on scanning near-field optical microscopic images in the far field 下载免费PDF全文
We have studied the influence of probe--sample interaction in a scanning near-field
optical microscopy (SNOM) in the far field by using samples with a step structure.
For a sample with a step height of $\sim \lambda $/4, the SNOM image contrast
between the two sides of the step changes periodically at different scan heights.
For a step height of $\sim \lambda $/2, the image contrast remains approximately the
same. The probe--sample interaction determines the SNOM image contrast here. The
influence of different refractive indices of the sample has been also analysed by
using a simple theoretical model. 相似文献
3.
4.
In addition to its well-known capabilities in imaging and spectroscopy, scanning near-field optical microscopy (SNOM) has recently shown its great potentials for fabricating various structures at the nanoscale. A variety of SNOM-based fabrication techniques have been developed for different applications. In this paper, the SNOM-based techniques involving three major functions: material modification, addition, and removal, are examined with emphasis on their abilities and reliability to make structures with resolutions at the nanometer level. The principles and procedures underlying each technique are presented, and the differences and uniqueness among them are subsequently discussed. Finally, concluding remarks are provided to summarize the major techniques studied and to recommend the scopes for technology improvement and future research. 相似文献
5.
Wu Shi-fa 《Frontiers of Physics in China》2006,1(3):263-274
This review has introduced a new near-field optical microscope (NOM)—atomic force microscope combined with photon scanning
tunneling microscope (AF / PSTM). During scanning, AF/PSTM could get two optical images of refractive index image and transmissivity
image, and two AFM images of topography image and phase image. A reflected near-field optical microscope (AF/RSNOM) has also
been developed on AF/PSTM platform. The NOM has been reviewed in this paper and the comparison between AF/PSTM & RSNOM and
the commercial A-SNOM & RNOM has also been discussed. The functions of AF/PSTM & RSNOM are much better than A-SNOM & RNOM. 相似文献
6.
GE Huayong GUO Qizhi TAN Weihan 《Chinese Journal of Lasers》2002,11(2):111-116
In this paper, the probe-sample interaction equation based on Mie's scattering theory is derived, and the resolution of scanning near field optical microscopy is calculated numerically. The results show that the offset of far-field component to near-field component in total field plays an important role in the resolution and the size of samples also has influence on resolution. 相似文献
7.
In this paper, the probe-sample interaction equation based on Mie′s scattering theory is derived, and the resolution of scanning near field optical microscopy is calculated numerically. The results show that the offset of far-field component to near-field component in total field plays an important role in the resolution and the size of samples also has influence on resolution. 相似文献
8.
Jian-Qi Zhang 《Physics letters. A》2010,374(37):3818-3822
We show that three initially nonresonant quantum dots (QDs) could be used to generate W-type entangled states with the application of a single detuned light via the ac Stark effect. This gives a way to prepare the highly entangled excitonic states in the picosecond time scale by controlling the interactions between QDs. 相似文献
9.
A coupled-dipole approach is proposed in order to study the coupling between the probe tip and the rough sample in SNOM. In the present model both the optical probe tip and the sample protrusions are represented by polarizable dipole spheres. The induced polarization effects on the sample surface can be replaced by the image dipoles in the circumstance of quasi-static electromagnetic field approximation. Applying the radiation theory of the dipole, we have established a set of self-consistent equations to describe the field distribution at the sites of the probe tip and the sample protrusions. The results are completely the same as those obtained by means of the dyadic electromagnetic propagator formalism and also the derivation procedure is relatively simple. This method permits us to analyze the physical mechanisms of the interaction between the probe tip and the rough surface in SNOM intuitively. Based on this approach, we further discuss the influence of polarization of the incident light on the imaging quality. The calculating result shows that the shape and the contrast of the images of the sample are both sensitive to the field polarization, and the z-polarized mode is proved to give better resolution in SNOM. 相似文献
10.
A novel scanning-probe setup is reported that maps the complex transmission of microwaves. Response to topographic features as small as 15 nm was observed. The sharpened coaxial probe tip serves as a microwave antenna and, at the same time, as a tunnel tip to warrant precise distance control by STM (scanning tunneling microscope) feedback. The instrument can be applied to map the microwave conductivity of, e.g. thin films or low-dimensional semiconductors. Consequences for the development of an infrared microscope are outlined. 相似文献
11.
利用荧光光度法测定食品中蛋白质的含量;实验以六偏磷酸钠为稳定剂,巯基乙酸为修饰剂水相合成了具有优异光学性质的CdS量子点.基于CdS与牛血清白蛋白(BsA)反应后,荧光强度显著增强,建立了CdS荧光光度法测定蛋白质的新方法;体系的荧光强度与BSA浓度在0.001 43~0.250 mg·mL-1范围内呈良好的线性关系,... 相似文献
12.
A. S. Kadochkin 《Journal of Applied Spectroscopy》2007,74(4):552-560
We have solved the problem in which a thin metal wafer (probe) with a nanohole interacts with the flat surface of a metastructured
film consisting of metal nanoparticles in an external optical radiation field. Nanoparticles are considered as two-level atomic
systems. This interaction of the wafer-probe and the flat surface in the external optical radiation field gives rise to optical
near-field resonance, the frequency of which differs significantly from the natural frequencies of two-level atoms in the
medium and the probe. The fields inside and outside the probe and metastructured film are calculated in the near-field and
far-field zones. The maximum resolution, which is achievable in the suggested scheme of near-field optical microscopy, can
reach about 10 nm.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 499–506, July–August, 2007. 相似文献
13.
An easy-to-implement non-optical shear-force detection setup for tip–sample distance regulation in scanning near-field optical microscopy is demonstrated. The detection method is based on attaching the near-field probe to a piezoelectric tube resulting in excellent mechanical contact between tip and detector. The main advantages of the method are good signal-to-background contrast and thus potential for high sensitivity. The method is demonstrated by obtaining approach curves of silicon surfaces. The suitability for optical experiments is further shown by measuring the near-field intensity distribution of the emission of a semiconductor laser. 相似文献
14.
为了研究扫描近场光学显微镜中探针和粗糙样品表面的耦合相互作用,提出了一种光耦合偶极子模型.在该模型中,探针和样品突起都由光极化偶极子表示,在准静态电磁场近似的情况下样品表面的诱导极化效应由影像偶极子表示,应用偶极子辐射理论可以得到系统的自洽场方程.此模型提供了一种直观分析扫描近场光学显微镜中探针和样品相互作用机理的方法.在此基础上,进一步讨论了金属样品的近场成像特点和其特有的局域光学共振现象.数值结果表明:不同于一般的介质样品,金属样品的近场图像与入射光频率直接相关,改变入射光的频率,获得的样品近场图像的形状和对比度都会发生变化.特别是当入射光频率处于样品极化共振范围内时,金属纳米粒子的极化率会出现光极化共振,这样就可以获得样品粒子的最大有效尺寸,为提高系统的分辨率提供了一条重要途径. 相似文献
15.
F. Ge C. Prasad A. Andresen J.P. Bird D.K. Ferry L.‐H. Lin N. Aoki K. Nakao Y. Ochiai K. Ishibashi Y. Aoyagi T. Sugano 《Annalen der Physik》2000,9(1):65-68
We describe the observation of novel localization in mesoscopic quantum dots and quantum dot arrays, which are realized in high mobility GaAs/AlGaAs heterojunctions using the split‐gate technique. With a sufficient gate voltage applied to form the devices, their resistance diverges as the temperature is lowered below a degree Kelvin, behavior which we attribute to localization. Evidence for the localization is found over the entire range of gate voltage for which the dots are defined, persisting to conductances higher than 50e2/h. 相似文献
16.
The optical waveguide behaviors of CdS and CdS
x
Se1−x
nanostructures are studied using near-field optical microscopy. Optical measurements demonstrate that light may be guided
on sub-wavelength scales along CdS nanoribbons in straight or bent structures. The photoluminescence (PL) spectra from nanoribbon
emission using scanning near-field optical microscopy are analyzed under different incident laser intensities. The PL spectra
along Se-doped and undoped CdS nanoribbons at different propagation distances are investigated. Both the guided PL spectra
of Se-doped and undoped CdS nanoribbons show red-shifts because of the band-edge absorption. Our results are useful for the
development of new kinds of functional nano devices.
Supported by the National Natural Science Foundation of China (Grant Nos. 10574002, 90406007, and 50602015) and the National
Basic Research Program of China (Grant No. 2007CB936800) 相似文献
17.
Adam Babinski M. Potemski S. Raymond M. Korkusinski W. Sheng P. Hawrylak Z. Wasilewski 《Physica E: Low-dimensional Systems and Nanostructures》2006,34(1-2):288
We report on the measurements of the photoluminescence from the s-shell of a single InAs/GaAs quantum dot in magnetic fields up to 23 T. The observed multiline emission is attributed to different charge states of a single dot. Characteristic anticrossing of emission lines is explained in terms of hybridization of final states of a triply charged exciton (X−3). 相似文献
18.
Dual mode near-field scanning optical microscopy for near-field imaging of surface plasmon polariton
In this paper, we theoretically and experimentally demonstrate that metal coated apertured probes are efficient near-field probes on surfaces with high reflectivity for the scattering as well as for the collection mode near-field scanning optical microscopy (NSOM). We show that a blunt apertured metal coated tip is very effective in suppressing image dipoles which affect strongly the signals scattered from frequently used sharp metal tips or gold nanoparticle attached probes. By using a simultaneous collection and scattering mode (dual mode) NSOM we measure the near-field images of surface plasmon polariton (SPP) launched from a slit. The collection mode measures propagating SPP along lateral distance in a long scan range with high signal-to-noise ratio, and the scattering mode measures the polarization resolved near-field of SPP. Comparisons of the measured data obtained in the dual mode enable to easily characterize SPP and to separate the measured near-field into the propagating SPP and the directly transmitted light. 相似文献
19.
M. van den Broek F. M. Peeters 《Physica E: Low-dimensional Systems and Nanostructures》2001,11(4):241
The energy spectrum and corresponding wave functions of a flat quantum dot with elliptic symmetry are obtained exactly. A detailed study is made of the effect of ellipticity on the energy levels and the corresponding wave functions. The analytical behavior of the energy levels in certain limiting cases is obtained. 相似文献
20.
M. Taut U. Landman C. Yannouleas 《Physica E: Low-dimensional Systems and Nanostructures》2004,24(3-4):308-317
The evolution of non-stationary localized states |Ψ(t=0) is investigated in two-dimensional tight binding systems of N potential wells with and without a homogeneous field perpendicular to the plane. Most results are presented in analytical form, what is almost imperative if the patterns are as complex as for rings in a magnetic field, where the qualitatively different features arise depending on rational or irrational numbers. The systems considered comprise finite linear chains (N=2,3), finite rings (N=3–6), infinite chains, finite rings (N=3–6) in a magnetic field, and rings with leads attached to each ring site. The position of the particle at time t is described by the projection of the wave function Pm(t)=|m|Ψ(t)|2 onto the localized basis function at site m. For finite chains and rings with N=3,4,6 the time evolution is periodic, whereas it is non-periodic for N=5 and N greater then 6. Rings in a magnetic field show a rich spectrum of different features depending on N and the number of flux quanta through the ring, including periodic oscillation and rotation of the charge as well as non-periodic charge fluctuations. 相似文献