State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics &Physics, Chinese Academy of Sciences, No.3888, Dongnanhu Road, Changchun, Jilin, P. R. China.
University of the Chinese Academy of Sciences, Beijing, 10039, P. R. China.
Sci Rep. 2016 Nov 29;6:37898. doi: 10.1038/srep37898.
Plasmonic structured illumination microscopy (PSIM) is one of the promising wide filed optical imaging methods, which takes advantage of the surface plasmons to break the optical diffraction limit and thus to achieve a super-resolution optical image. To further improve the imaging resolution of PSIM, we propose in this work a so called graphene nanocavity on meta-surface structure (GNMS) to excite graphene surface plasmons with a deep sub-wavelength at mid-infrared waveband. It is found that surface plasmonic interference pattern with a period of around 52 nm can be achieved in graphene nanocavity formed on structured meta-surface for a 7 μm wavelength incident light. Moreover, the periodic plasmonic interference pattern can be tuned by simply changing the nanostructures fabricated on meta-surface for different application purposes. At last, the proposed GNMS structure is applied for super-resolution imaging in PSIM and it is found that an imaging resolution of 26 nm can be achieved, which is nearly 100 folds higher than that can be achieved by conventional epi-fluorescence microscopy. In comparison with visible waveband, mid-infrared is more gently and safe to biological cells and thus this work opens the new possibility for optical super-resolution imaging at mid-infrared waveband for biological research field.
等离子体结构光照明显微镜（PSIM）是一种很有前途的宽场光学成像方法，它利用表面等离激元突破光学衍射极限，从而实现超分辨率光学图像。为了进一步提高 PSIM 的成像分辨率，我们提出了一种所谓的基于亚表面结构的石墨烯纳米腔（GNMS），以在中红外波段用深亚波长激发石墨烯表面等离激元。研究发现，对于 7 μm 波长的入射光，在结构化亚表面上形成的石墨烯纳米腔中可以实现周期约为 52nm 的表面等离激元干涉图案。此外，通过简单地改变亚表面上制造的纳米结构，可以针对不同的应用目的来调整周期性等离子体干涉图案。最后，将所提出的 GNMS 结构应用于 PSIM 的超分辨率成像，发现可以实现 26nm 的成像分辨率，比传统的荧光显微镜可实现的分辨率高近 100 倍。与可见光波段相比，中红外对生物细胞更为温和和安全，因此这项工作为生物研究领域的中红外波段光学超分辨率成像开辟了新的可能性。
