A Plasmonic Sensor Array with Ultrahigh Figures of Merit and Resonance Linewidths down to 3 nm |
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| Authors: | Bowen Liu Shu Chen Jiancheng Zhang Xu Yao Haixin Lin Tengxiang Huang Zhilin Yang Jinfeng Zhu Shou Liu Christoph Lienau Lei Wang Bin Ren |
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| Affiliation: | 1. State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), the MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China;2. Department of Physics, Xiamen University, Xiamen, China;3. School of Aerospace Engineering, Xiamen University, Xiamen, China;4. Department of Electronic Science, Xiamen University, Xiamen, China;5. Institute of Physics and Center of Interface Science, Carl von Ossietzky University, Oldenburg, Germany |
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| Abstract: | Surface plasmon polaritons (SPPs) are extremely sensitive to the surrounding refractive index and have found important applications in ultrasensitive label‐free sensing. Reducing the linewidth of an SPP mode is an effective way to improve the figure of merit (FOM) and hence the sensitivity of the plasmonic mode. Many efforts have been devoted to achieving a narrow linewidth by mode coupling, which inevitably results in an asymmetrical lineshape compromising the performance. Instead, the SPP modes are directly narrowed by elaborately engineering periodic plasmonic structures with minimized feature sizes to effectively reduce the radiative losses. A narrow linewidth smaller than 8 nm is achieved over a wide wavelength ranging from 600 to 960 nm and a minimum full width at half maximum of 3 nm at 960 nm. Benefiting from the almost perfect Lorentzian lineshape and the extremely narrow linewidth, a record FOM value of 730 is obtained. The sensor is capable of detecting bovine serum albumin with an ultralow concentration of 10?10m . The sensor has great potential for practical application for its ultrahigh FOM, broad working wavelength, and ease of high‐throughput fabrication. |
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| Keywords: | metasurfaces nanofabrication optical losses optical sensor plasmonic structures |
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