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1.
We report on the development of a cantilever-based scanning near-field optical microscope (SNOM) working in an extreme environment,
at cryogenic temperature around 10 K and under strong magnetic field up to 7 T. We designed a new optical system based on
an infinite conjugate microscope, which extracts the near-field signal from a small aperture through a narrow chamber into
free space as collimated light. Using this system, we successfully measured near-field and topographical images of a metal-hole
sample simultaneously. Combining the local optical accessing technique with the external control of the electronic state,
this SNOM system will be a powerful tool to study optical properties of semiconductor nanostructures. 相似文献
2.
The research on the setup and application of scanning near-field optical microscopy (SNOM) performed in our laboratory is reviewed in this report. We have constructed a versatile low temperature scanning near-field optical microscope with the capability of near-field imaging and spectroscopy, operating at liquid nitrogen temperature. A special designed coaxial double lens was used to introduce the illumination beam through a 200μm fiber; the detected optical signal was transmitted via a fiber tip to an avalanche photon detector. The performance test shows the stability of the new design. The shear force image and optical image of a standard sample are shown. A system of SNOM working at room temperature and atmosphere was used to characterize semiconductors and bio-molecular samples. It revealed the unique features of semiconductor microdisks in the near-field that is significantly different from that of far-field. The effects of different geographic microstructures on the near-field light distribution of InGaP, GaN, and InGaN multi-quantum-well microdisk were observed. 相似文献
3.
4.
Hiroshi Muramatsu Norio Chiba Tatsuaki Ataka Shinichiro Iwabuchi Naoki Nagatani Eiichi Tamiya Masamichi Fujihira 《Optical Review》1996,3(6):470-474
We have developed a system of scanning near-field optical/atomic force microscopy (SNOM/AFM) for fluorescence imaging and spectroscopy of biomaterials in air and liquid. SNOM/AFM uses a bent optical fiber simultaneously as a dynamic force AFM cantilever and a SNOM probe. Optical resolution of SNOM images shows about 50 nm in an illumination mode for a standard sample of a patterned chromium layer of 20 nm thickness on a quartz glass plate. The SNOM/AFM system contains a photon counting system and polychrometer/ICCD (intensified charge coupled device) system for observation of the fluorescence image and spectrograph of micro areas, respectively. The gene coding to green fluorescence protein (GFP) was cloned in recombinantEscherichia coli (E. coli). Topography, fluorescence image and spectrograph of recombinantE. coli by SNOM/AFM showed a difference in fluorescence in individualE. coli. Fluorescence activity of GFP can thus be used as a convenient indicator of transformation. SNOM/AFM is also applicable to observe immobilizedE. coli on a glass plate in water with a liquid chamber and may allow the viewing of observation of floating organisms. 相似文献
5.
Optical polarization response at gold nanosheet edges probed by scanning near-field optical microscopy
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Optical properties of metallic edge-like structures known as knife-edges are a topic of interest and possess potential applications in enhanced Raman scattering, optical trapping, etc. In this work, we investigate the near-field optical polarization response at the edge of a triangular gold nanosheet, which is synthesized by a wet chemical method. A homemade scanning near-field optical microscope(SNOM) in collection mode is adopted, which is able to accurately locate its probe at the edge during experiments. An uncoated straight fiber probe is used in the SNOM, because it still preserves the property of light polarization though it has the depolarization to some extent. By comparing near-field intensities at the edge and glass substrate, detected in different polarization directions of incident light, the edge-induced depolarization is found,which is supported by the finite differential time domain(FDTD) simulated results. The depolarized phenomenon in the near-field is similar to that in the far-field. 相似文献
6.
High-resolution single molecular near-field fluorescence images were observed by scanning near-field optical/atomic force microscopy (SNOM/AFM). We modified the SNOM/AFM for both high-resolution fluorescence imaging and high-resolution topographic imaging. The imaged fluorophore, Alexa 532, is prepared with a poly-methyl-methacrylate (PMMA) film coating. A fluorescence resolution of 25 nm was obtained with a simultaneous topographic image of a flat surface. A sample prepared with a lower PMMA concentration exhibited a rough surface in the micro area. The results for the flat surface indicated that the fluorescence resolution is worst in the rough surface sample, that the maximum fluorescence intensities for the individual fluorophore are similar, and that the decay rate is faster. Thus, we concluded that the morphological effect is an important factor in fluorescence image resolution and the apparent lifetimes of the fluorescence molecules. 相似文献
7.
In this paper, we study the dynamic modes of a scanning near-field optical microscope (SNOM) which uses an optical fiber probe; and the sensitivity of flexural and axial vibration modes for the probe were derived and the closed-form expressions were obtained. According to the analysis, as expected each mode has a different sensitivity and the first mode is the most sensitive mode of flexural and axial vibration for the SNOM probe. The sensitivities of both flexural and axial modes are greater for a material surface that is compliant with the cantilever probe. As the contact stiffness increases, the high-order vibration modes are more sensitive than the lower-order modes. Furthermore, the axial contact stiffness has a significant effect on the sensitivity of the SNOM probe, and this should be noted when designing new cantilever probes. 相似文献
8.
Use of a scanning near-field optical microscope architecture to study fluorescence and energy transfer near a metal 总被引:1,自引:0,他引:1
Fluorescence intensity depends strongly on the distance between the emitting molecule and a metallic interface. We show that a scanning near-field optical microscope (SNOM) is a simple and versatile tool for studying such an effect. The fluorescent molecules are embedded in a layer upon a silica substrate, and metal is coated on the SNOM tip. We present variations of fluorescence intensity versus tip-sample distance from 800 to ~80 nm . A simple model is used to explain the experimental results. The proposed setup could be used to study nonradiative transfer at a nanometric scale. It could also yield to a new type of optical near-field profiler that uses fluorescent signal. 相似文献
9.
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
10.
Sumio Hosaka Toshimichi Shintani Atsushi Kikukawa Kenchi Itoh 《Applied Surface Science》1999,140(3-4):388-393
We study a nanometer-sized optical probe and image in a scanning near-field optical microscope (SNOM). We demonstrated the potential to observe 5-nm wide optical patterns using the SNOM. The probe profile was measured by using a knife-edge method and a modulated transfer function evaluation method. An aluminum covered and pipet-pulled fiber probe used here has two optical probes, one which has a large diameter of 350 nm and one which has a small diameter of around 10 nm. 相似文献
11.
Anisha Gokarna Yong Hwan Kim Yong-Hoon Cho Min Su Lee In Cheol Kang Hyun Kyu Park Min Gon Kim Bong Hyun Chung 《Optical Review》2006,13(4):288-291
We demonstrate the fluorescence mapping of protein microarrays by the technique of scanning near-field optical microscopy
(SNOM) and confocal microscopy. Micron sized spots (300 μm) of human Immunoglobulin G (hIgG) protein with and without a Cy3
dye labeling have been fabricated on glass substrates by an immobilization method which makes use of calixcrown derivatives
termed Prolinker. We have also tried to probe into the well-known “doughnut effect” observed in fluorescence images of proteins
using the SNOM technique. The topographic and fluorescence SNOM images revealed that the number of proteins at the boundary
of the spot were more than at the center in the case of the microarray spot which showed brighter luminescence at the edge
than at the center in the confocal image. 相似文献
12.
Fujimura T Edamatsu K Itoh T Shimada R Imada A Koda T Chiba N Muramatsu H Ataka T 《Optics letters》1997,22(8):489-491
Scanning near-field optical images of hexagonally close-packed layers of polystyrene spherical particles with a diameter of 1.0 microm have been investigated. The layers were composed of particles that were doped either totally or partially with an organic fluorescent dye. Observations were made in the transmission and luminescence excitation modes with a scanning near-field optical microscope (SNOM) with a spatial resolution shorter than the wavelength of light. The patterns observed in the SNOM images are significantly dependent on the microstructures of layers, that is, the layers are either single or double layered, and the particles are either totally or partially doped. These results are discussed in terms of specific modes of electromagnetic waves transmitting across and along the layers after the local excitation at the tip end of the scanning microprobe. 相似文献
13.
We theoretically investigate scanning near-field optical microscopy (SNOM) of semiconductor quantum dots. A general theoretical framework is developed that accounts for photo excitation and relaxation in complex dielectric environments. We find that in the near-field regime bright and dark excitonic states become mixed, opening new channels for the coupling to the electromagnetic field. 相似文献
14.
V. Anikeyev V. V. Temnov U. Woggon E. Devaux T. W. Ebbesen 《Applied physics. B, Lasers and optics》2008,93(1):171-176
We discuss the implications of a frequency-dependent complex dielectric function ε(ω) of a metal for the interpretation of scanning near-field optical microscopy (SNOM) measurements in the vicinity of metallic
nanoapertures. For subwavelength slits in gold films we observe distinct spatial intensity oscillations in the near-field
signal for specific wavelengths in the visible spectrum. These oscillations of the SNOM signal far away from the nanoslit
are ascribed to a constructive interference between the propagating surface plasmon (SP) with light scattered parallel to
the gold–air interface. In these spatial SNOM-signal oscillations information about the surface plasmon dielectric function
is encoded which can be extracted, for example, in surface plasmon interferometry for applications as sensors or waveguides. 相似文献
15.
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
16.
Realization of a near-field optical virtual probe based on an evanescent Bessel beam is strongly dependent on a radially polarized
beam; this makes it essential to study the focusing property of the beam. In this paper, two experimental setups based on
a fiber device and a liquid crystal device, respectively, are built to generate a radially polarized beam. This beam and an
annular radially polarized beam are focused by means of a high numerical aperture objective and a solid immersion lens (SIL).
Near-field distribution of the focus spot, the evanescent Bessel field, is experimentally measured with a scanning near-field
optical microscope (SNOM). The full width at half maximum (FWHM) of the central peak of the evanescent Bessel field is about
200 nm in the close vicinity of the bottom surface of SIL. This has potential for use as a near-field optical virtual probe. 相似文献
17.
KITAZAWA Tazuko MIYANISHI Shintaro MURAKAMI Yoshiteru KOJIMA Kunio TAKAHASHI Akira 《中国物理快报》2007,24(10):2827-2829
We observe surface plasmon polariton (SPP) refraction on a metal heterostructured sample with a scattered-type scanning near-field optical microscope (SNOM). The sample consists of AI and Au in-plane whose boundary is smooth enough with proper etching time. SPPs excited on the AI film travel to the boundary and a portion of SPPs propagates into the Au film. In addition, interference fringes appear in the SNOM image bent at the boundary. The result is analysed with effective index method and the refracted angle is explained by Shell's law. 相似文献
18.
Imaging of human meiotic chromosomes by scanning near-field optical microscopy (SNOM) 总被引:2,自引:0,他引:2
Hausmann M Liebe B Perner B Jerratsch M Greulich KO Scherthan H 《Micron (Oxford, England : 1993)》2003,34(8):441-447
Centromeres and telomeres are key structures of mitotic and meiotic chromosomes. Especially telomeres develop particular structural properties at meiosis. Here, we investigated the feasibility of scanning near-field optical microscopy (SNOM) for light-microscopic imaging of meiotic telomeres in the sub-hundred nanometer resolution regime. SNOM was applied to visualise the synaptonemal complex (SC) and telomere proteins (TRF1, TRF2) after differential immuno-fluorescent labelling. We tested and compared two different preparation protocols for their applicability in a SNOM setting using micro-fabricated silicon nitride aperture tips. Protocol I consisted of differential labelling of meiotic chromosome cores (SC) by SCP3 immuno-fluorescence and telomeres by TRF1 or TRF2 immuno-fluorescence, while protocol II combined absorption labelling with alkaline phosphatase substrates of cores with fluorescent labelling of telomeres. The results obtained indicate that protocol I reveals a better visualisation of structural (topographic) details than protocol II. By means of SNOM, meiotic chromosome cores could be visualised at a resolution overtopping that of far-field light microscopy. 相似文献
19.
Influence of the probe--sample interaction on scanning near-field optical microscopic images in the far field
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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
20.
Hongliang Ren Chun Jiang Weisheng Hu Mingyi Gao Jingyuan Wang Hui Wang Jintian He Erjun Liang 《Optics & Laser Technology》2007,39(5):1025-1029
As an important component of scanning near-field optical microscope (SNOM), optical fibre nanoprobe has been applied to many fields extensively. A melt-stretched etching method is proposed to produce optical fibre nanoprobe with low cost. Firstly, optical fibre tip with micrometer-sized diameter is created by the melt-stretched measure. Next, it is dipped into hydrofluoric acid (HF), and a fine optical fibre nanoprobe will be made after a short-time etching. Owing to the taper structure of tip, it can be etched again in acid if a nanoprobe is not constructed when the first etching is completed. In addition, optical fibre nanoprobe is applied to spectral investigation, and the fluorescence spectroscopy of rhodamine B (Rh B) solution is collected by an optical investigation system with a bifurcated fibre. 相似文献