共查询到20条相似文献,搜索用时 18 毫秒
1.
Three-dimensional modeling of amplitude-object imaging in scanning near-field optical microscopy 总被引:3,自引:0,他引:3
The imaging properties of the transmission-illumination mode of a scanning near-field optical microscope are investigated. Three-dimensional calculations of the power transmitted into classically allowed and forbidden regions for a nonsymmetrically positioned amplitude object are implemented by use of the finite-difference time-domain solution of Maxwell's equations. The evolution of the images with the distance from the object as well as the effect of the polarization of the illumination is shown. The computations show that for applications involving the imaging of an amplitude object, the use of the allowed light is preferred. Collection of light from both the allowed and the forbidden zones leads to degraded contrast and resolution. 相似文献
2.
Faraday-rotation imaging by near-field optical microscopy 总被引:2,自引:0,他引:2
Thilo Lacoste Thomas Huser Harry Heinzelmann 《Zeitschrift für Physik B Condensed Matter》1997,104(2):183-184
Scanning near-field optical microscopy with polarization modulation (PM-SNOM) has been applied to image the surface of a yttrium-iron-garnet (YIG) film. Lock-in detection of the phase of the transmitted light directly gives the magnitude of the Faraday rotation angle. 相似文献
3.
Fasolka MJ Goldner LS Hwang J Urbas AM DeRege P Swager T Thomas EL 《Physical review letters》2003,90(1):016107
Ultrahigh molecular weight polystyrene-b-polyisoprene block copolymers (BCs), noted for their photonic behavior, were imaged using transmission near-field scanning optical microscopy (NSOM) and NSOM polarimetry. Our improved scheme for polarization modulation (PM) polarimetry, which accounts for optical anisotropies of the NSOM aperture probe, enables mapping of the local diattenuation and birefringence (with separately aligned diattenuating and fast axes) in these specimens with subdiffraction limited resolution. PM-NSOM micrographs illuminate the mesoscopic optical nature of these BC specimens by resolving individual microphase domains and defect structures. 相似文献
4.
In apertureless scanning near-field optical microscopy (ASNOM), the probe vibration is often used to increase the detected signal. The useful signal is detected at the probe-vibration frequency by a lock-in amplifier. By comparing two-dimensional numerical results with an experimental scan, we show numerically that, to explain or predict the detected signal, a realistic model of ASNOM should take into account the scan of the probe as well as the probe vibration and the material properties. 相似文献
5.
《中国物理 B》2015,(5)
Phase is one of the most important parameters of electromagnetic waves. It is the phase distribution that determines the propagation, reflection, refraction, focusing, divergence, and coupling features of light, and further affects the intensity distribution. In recent years, the designs of surface plasmon polariton(SPP) devices have mostly been based on the phase modulation and manipulation. Here we demonstrate a phase sensitive multi-parameter heterodyne scanning near-field optical microscope(SNOM) with an aperture probe in the visible range, with which the near field optical phase and amplitude distributions can be simultaneously obtained. A novel architecture combining a spatial optical path and a fiber optical path is employed for stability and flexibility. Two kinds of typical nano-photonic devices are tested with the system. With the phase-sensitive SNOM, the phase and amplitude distributions of any nano-optical field and localized field generated with any SPP nano-structures and irregular phase modulation surfaces can be investigated. The phase distribution and the interference pattern will help us to gain a better understanding of how light interacts with SPP structures and how SPP waves generate, localize, convert, and propagate on an SPP surface. This will be a significant guidance on SPP nano-structure design and optimization. 相似文献
6.
7.
Romain Lecaque Samuel Grésillon Nicolas Barbey Romain Peretti Jean-Claude Rivoal Claude Boccara 《Optics Communications》2006,262(1):125-128
A new THz imaging system based on a local illumination by a near-field source is presented. Model object is imaged, and sub-wavelength spatial resolution is demonstrated for the first time to our knowledge with this configuration. The contrast and the resolution are confirmed by a theoretical study based on the diffraction in near-field zone. 相似文献
8.
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
9.
10.
Naoya Tate Makoto Naruse Yang Liu Tadashi Kawazoe Takashi Yatsui Motoichi Ohtsu 《Applied physics. B, Lasers and optics》2013,112(4):587-592
We have previously demonstrated a novel technique for autonomously forming a nanophotonic droplet, which is micro-scale spherical polymer structure that contains paired heterogeneous nanometric components. The sort-selectivity and alignment accuracy of the nanometric components in each nanophotonic droplet, and the related homogeneity of the optical function, are due to a characteristic pairing process based on a phonon-assisted photo-curing method. The proposed method requires irradiating a mixture of components with light to induce optical near-field interactions between each component, and subsequent processes based on these interactions. The pairing yield of components via the interactions is considered to mainly depend on the frequency of their encounters and the size-resonance effect between encountered components. In this paper, we model these two factors by individual stochastic procedures and construct a numerical model to describe the pairing process. Agreement between the results of numerical and experimental demonstrations shows the validity of our stochastic modeling. 相似文献
11.
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
12.
In near-field optics, measurement of vertical variations of the near field is of great interest for characterizing the efficiency of resonances such as surface plasmon polaritons. The use of the signal obtained through the lock-in amplifier using a feedback on the vertical vibration of the probe is shown to enable the reconstruction of the near field without the use of the slower technique of approach curves. Therefore, a tomography of the near field is directly available. 相似文献
13.
14.
David J. Hwang Bin Xiang Sang-Gil Ryu Oscar Dubon Andrew M. Minor Costas P. Grigoropoulos 《Applied Physics A: Materials Science & Processing》2011,103(2):317-321
A GaN-to-InGaN interface modification by predeposition of an ultrathin In-rich InGaN incomplete layer followed by a thin triangular
InGaN well layer was employed to overcome the negative effects of polarization field on light emission efficiency of InGaN/GaN
quantum wells as well as to improve the crystalline quality by avoidance of a significant strain generation and enhanced surfactant
effect. Further, the interface modification induced energy band structure engineering reduces the spatial separation of electrons
and holes, and thus increases the carrier recombination rate. The improvement in crystalline quality, localized potential
fluctuation, and energy band engineering contribute to the significant increase of green emission of the InGaN/GaN quantum
wells. 相似文献
15.
R. Kirschner 《Physics letters. [Part B]》1984,139(3):180-182
We show the supersymmetry mechanism responsible for the quantization by stochastic relaxation processes and for the effective cancellation of the additional time dimension against the two Grassmann dimensions. We give a non-perturbative proof of the validity of this quantization procedure. 相似文献
16.
We propose a method of near-field recording in a space that is quite apart from the original source (generator) of optical near fields. The method is based on the recently developed technique of near-field holography. Experiments based on our method have shown that near fields that originate from sub-diffraction-limit-sized objects can be stored in a photorefractive crystal 2 mm apart from the crystal surface, resulting in the retrieval of sub-diffraction-limit-sized spots. This means that our scheme can provide a method for multilayer (stackwise) near-field storage and, thus, contribute to a significant enhancement of the storage capacity of near-field optical memory. 相似文献
17.
《Superlattices and Microstructures》1999,25(1-2):361-365
We present a theoretical study of optical second-harmonic generation(SHG) of symmetric semiconductor quantum dots (QDs) excited by the near field of the tip in a near-field scanning optical microscope. We show that the usual optical transition selection rules for the SH nonlinear interaction between the tip field and the QD are broken when the tip is scanned over the QD, because the tip field varies rapidly over the QD domain. It is also demonstrated that the tip-position dependence of the SH signal essentially maps the spatial distribution of the tip field. 相似文献
18.
Vladimir Belitsky 《Journal of statistical physics》1993,70(5-6):1233-1254
We study an interacting particle system on a one-dimensional infinite lattice and one-dimensional lattices with a periodic boundary. In this system, each site of the lattice may be either empty or occupied and initially all the lattice sites are empty. The evolution of the system is defined as follows: an empty site waits an exponential time with mean 1 and becomes occupied, and an occupied site becomes empty at a time which is distributed exponentially with mean
k, wherek is the number of occupied neighboring sites of this site in the current state of the system. We show that the mean number of the occupied sites of the lattice, considered as a function of time, may possess a convex part. A sufficient condition for this is that
0 is large and
k,k1, are small. The studied system has been proposed recently as a mathematical model of certain deposition processes, in particular those which exhibit nucleation caused by lateral attractive interaction between the deposited molecules. Our research was motivated by the observation that the density of deposited molecules contains a convex part, over some time interval, if the attractive forces are strong, while this density is a concave function of time if these forces are weak or absent. Our result agrees with this observation. 相似文献
19.
T. Yatsui Y. Nakajima W. Nomura M. Ohtsu 《Applied physics. B, Lasers and optics》2006,84(1-2):265-267
We propose a novel method to increase the resolution of imprint lithography by introducing strong localization of the optical
near-field intensity, depending on the mold structure. By optimizing the thickness of the metallic film on a SiO2 line-and-space (LS) mold without a sidewall coating, we confirmed that the optical near-field strongly localizes at the edge
of the mold, using a finite-difference time-domain calculation method. Based on the calculated results, we performed optical
near-field imprint lithography using a mold with metallized (20-nm-thick Al without a sidewall coating) SiO2 LS with a 300-nm half-pitch that was 200-nm deep with illumination using the g-line (λ=436 nm), and obtained features as
narrow as 50 nm wide.
PACS 81.16.Nd; 81.16.Rf 相似文献
20.
J. Muller 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(7):1162-1169
The detection of surface waves through scanning near-field optical microscopy (SNOM) is a promising technique for thermal measurements at very small scales. Recent studies have shown that electromagnetic waves, in the vicinity of a scattering structure such as an atomic force microscopy (AFM) tip, can be scattered from near to far-field and thus detected. In the present work, a model based on the finite difference time domain (FDTD) method and the near-field to far-field (NFTFF) transformation for electromagnetic waves propagation is presented. This model has been validated by studying the electromagnetic field of a dipole in vacuum and close to a dielectric substrate. Then simulations for a tetrahedral tip close to an interface are presented and discussed. 相似文献