Resolution Enhancement of Plasmonic Sensors by Metal‐Insulator‐Metal Structures |
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| Authors: | Siham Refki Shinji Hayashi Hidekazu Ishitobi Dmitry V. Nesterenko Anouar Rahmouni Yasushi Inouye Zouheir Sekkat |
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| Affiliation: | 1. Optics and Photonics Center, Moroccan Foundation for Advanced Science Innovation and Research (MAScIR), Rabat, Morocco;2. Faculty of Sciences, Mohammed V University in Rabat, Morocco;3. Graduate School of Engineering, Kobe University, Kobe, Japan;4. Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan;5. Department of Applied Physics, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan;6. Advanced Photonics and Biosensing Open Innovation Laboratory, AIST‐Osaka University, Suita, Osaka, Japan;7. Image Processing Systems Institute – Branch of the Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, Samara, Russia;8. Samara National Research University, Samara, Russia;9. Photonics Advanced Research Center (PARC), Graduate School of Engineering, Osaka University, Suita, Osaka, Japan |
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| Abstract: | Optical sensors based on surface plasmons have attracted much attention over the past decades owing to the wealth of applications in bio‐ and chemical and gas sensing. In surface plasmon resonance sensors, a single metal layer is commonly used, but its resolution is limited because of broad resonances. In this context, we have developed a sensor chip based on a stack of metals and a dielectric, e.g. a metal‐insulator‐metal structure, consisting of a thick insulator layer sandwiched by metal layers, that exhibits a sharp resonance due to the excitation of surface plasmon polaritons hybrid modes. We have performed both experiments and theoretical simulations to estimate the enhancement of the sensitivity of such a structure. By changing the refractive index of an aqueous solution of glucose on top of the sensor chip, we found that the use of a metal‐insulator‐metal structure improves the figure of merit of the sensor 7.5 times compared to that of a conventional surface plasmon resonance sensor chip. |
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| Keywords: | metal‐insulator‐metal structures sensors surface plasmons |
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