Adiabatic Nanofocusing Scattering-Type Optical Nanoscopy of Individual Gold Nanoparticles
Adiabatic Nanofocusing Scattering-Type Optical Nanoscopy of Individual Gold Nanoparticles
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DOI：
10.1021/nl1045457
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发表时间：
2011-04-01
期刊：
影响因子：
10.8
通讯作者：
Lienau, Christoph
中科院分区：
文献类型：
--
作者：
Sadiq, Diyar;Shirdel, Javid;Lienau, Christoph
我们探索成像的局部电磁场附近的金属纳米粒子使用光栅耦合散射型近场扫描光学显微镜。在这种显微镜中，传播表面等离子体激元波包发射到光滑的金锥体上，在那里它们被螺旋聚焦到纳米尺寸的锥体顶点。我们报告二维光栅扫描的光学图像显示出明显的近场对比度，并展示了子30 nm分辨率成像的局部表面等离子体激元场的球形和椭圆形nanoparticies。通过比较三维时域有限差分模拟，我们得出结论，几乎实现了无背景近场成像。该显微镜结合了深亚波长分辨率，高局部场强度和直接的成像对比度，使其在线性和非线性纳米光谱学的各种应用有趣。
We explore imaging of local electromagnetic fields in the vicinity of metallic nanoparticles using a grating-coupled scattering-type near-field scanning optical microscope. In this microscope, propagating surface plasmon polariton wavepackets are launched onto smooth gold tapers where they are adiabatically focused toward the nanometer-sized taper apex. We report two-dimensional raster-scanned optical images showing pronounced near-field contrast and demonstrating sub-30 nm resolution imaging of localized surface plasmon polariton fields of spherical and elliptical nanoparticies. By comparison to three-dimensional finite-difference time domain simulations, we conclude that virtually background-free near-field imaging is achieved. The microscope combines deep subwavelength resolution, high local field intensities and a straightforward imaging contrast; making it interesting for a variety of applications in linear and nonlinear nanospectroscopy.