共查询到20条相似文献，搜索用时 46 毫秒
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扫描近场光学显微镜光纤探针的制作与分析 总被引：3，自引：0，他引：3
描述了制作扫描近场光学显微镜光纤探针的两种简便有效的方法－－带保护层的化学腐蚀法和光纤熔接机拉锥法,从实验中比较、分析了两种制作方法的优缺点,实验表明这两种方法均能制作出针尖直径为５０ｎｍ左右的光纤探针。 相似文献
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利用双谱分析方法,用非高斯AR模型对雷达目标回波信号进行参数化双谱估计,并在此基础上对数据进行外推处理,然后对数据进行ISAR成像。仿真和实测数据实验表明,本文的处理方法比传统的ISAR成像分辨力有明显的提高,且运算量不大,满足ISAR的实时或者准实时成像要求。 相似文献
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超分辨光学显微成像技术具有非接触、无损伤等优点。现有超分辨成像手段大多依赖荧光染料,限制其应用场合。近年来基于频谱平移原理的无标记远场显微成像手段被提出,但其分辨率受限于波导材料折射率。利用双曲超材料(hyperbolic metamaterials,HMM)的空间频率带通滤波特性,结合亚波长光栅,激发大面积均匀高频体等离激元(bulk plasmon polariton,BPP)照明场,得益于照明的高波矢量,物体的高频信息可以转移到传统成像系统的通带,为远场图像提供亚波长空间信息。基于该方法,采用0.85数值孔径标准物镜,532 nm波长下2.66k0横向波矢的BPP照明中心距为100 nm双缝结构成像,横向分辨力提高至λ/5.32。进一步提高BPP的横向波矢可使分辨力提升至λ/7.82。该方法无需标记,便于与传统显微镜集成,为生物医学、芯片工业、材料科学等领域的应用提供了一种可视化的超分辨手段。 相似文献
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Xinzhong Chen Debo Hu Ryan Mescall Guanjun You D. N. Basov Qing Dai Mengkun Liu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(24)
Infrared and optical spectroscopy represents one of the most informative methods in advanced materials research. As an important branch of modern optical techniques that has blossomed in the past decade, scattering‐type scanning near‐field optical microscopy (s‐SNOM) promises deterministic characterization of optical properties over a broad spectral range at the nanoscale. It allows ultrabroadband optical (0.5–3000 µm) nanoimaging, and nanospectroscopy with fine spatial (<10 nm), spectral (<1 cm?1), and temporal (<10 fs) resolution. The history of s‐SNOM is briefly introduced and recent advances which broaden the horizons of this technique in novel material research are summarized. In particular, this includes the pioneering efforts to study the nanoscale electrodynamic properties of plasmonic metamaterials, strongly correlated quantum materials, and polaritonic systems at room or cryogenic temperatures. Technical details, theoretical modeling, and new experimental methods are also discussed extensively, aiming to identify clear technology trends and unsolved challenges in this exciting field of research. 相似文献
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Jianing Chen Pablo Albella Zhaleh Pirzadeh Pablo Alonso‐González Florian Huth Stefano Bonetti Valentina Bonanni Johan Åkerman Josep Nogués Paolo Vavassori Alexandre Dmitriev Javier Aizpurua Rainer Hillenbrand 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(16):2341-2347
The fundamental optical properties of pure nickel nanostructures are studied by far‐field extinction spectroscopy and optical near‐field microscopy, providing direct experimental evidence of the existence of particle plasmon resonances predicted by theory. Experimental and calculated near‐field maps allow for unambiguous identification of dipolar plasmon modes. By comparing calculated near‐field and far‐field spectra, dramatic shifts are found between the near‐field and far‐field plasmon resonances, which are much stronger than in gold nanoantennas. Based on a simple damped harmonic oscillator model to describe plasmonic resonances, it is possible to explain these shifts as due to plasmon damping. 相似文献
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Denitza Denkova Niels Verellen Alejandro V. Silhanek Pol Van Dorpe Victor V. Moshchalkov 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(10):1959-1966
The design of many promising, newly emerging classes of photonic metamaterials and subwavelength confinement structures requires detailed knowledge and understanding of the electromagnetic near‐field interactions between their building blocks. While the electric field distributions and, respectively, the electric interactions of different nanostructures can be routinely measured, for example, by scattering near‐field microscopy, only recently experimental methods for imaging the magnetic field distributions became available. In this paper, we provide direct experimental maps of the lateral magnetic near‐field distributions of variously shaped plasmonic nanoantennas by using hollow‐pyramid aperture scanning near‐field optical microscopy (SNOM). We study both simple plasmonic nanoresonators, such as bars, disks, rings and more complex antennas. For the studied structures, the magnetic near‐field distributions of the complex resonators have been found to be a superposition of the magnetic near‐fields of the individual constituting elements. These experimental results, explained and validated by numerical simulations, open new possibilities for engineering and characterization of complex plasmonic antennas with increased functionality. 相似文献
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传统光学成像实质上是目标场景的光强信号在空间维度上的直接均匀采样记录与再现的过程。因此,其成像分辨率与信息量不可避免地受到光学衍射极限、成像系统空间带宽积等若干物理条件制约。如何突破这些物理制约,获得更高分辨率、更宽广的图像信息,一直是该领域的永恒课题。计算光学成像通过前端光学调控与后端信号处理相结合,为突破成像系统的衍射极限限制,实现超分辨成像提供了新思路。本文综述了基于计算光学合成孔径成像实现成像分辨率的提升以及空间带宽积拓展的相关研究工作,主要包括基于相干主动合成孔径成像与非相干被动合成孔径成像的基础理论及关键技术。本文进一步揭示了当前“非相干、无源被动、超衍射极限”成像的迫切需求及其现阶段存在的瓶颈问题,并展望了今后的研究方向以及解决这些问题可能的技术途径。 相似文献
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