{"title":"Transmissive hybrid metal–dielectric metasurface bandpass filters for mid-infrared applications","authors":"Amr Soliman, Timothy D. Wilkinson","doi":"10.1515/nanoph-2025-0122","DOIUrl":null,"url":null,"abstract":"Mid-infrared (MIR) spectroscopy plays a pivotal role in molecular identification and biosensing due to its ability to probe characteristic vibrational fingerprints of biomolecules. Plasmonic nanostructures have been explored for MIR applications but suffer from low efficiencies and broad spectral responses caused by intrinsic ohmic losses. All-dielectric metasurfaces, with low optical losses, offer an attractive alternative; however, their functionality is often restricted to reflection-mode operation. This work introduces a hybrid metal–dielectric metasurface designed to operate in transmission mode, specifically tailored for molecular identification in MIR biosensing applications. The metasurface comprises germanium (Ge) on aluminum (Al) cylinders atop a calcium fluoride (CaF<jats:sub>2</jats:sub>) substrate, optimized to exhibits a high transmission efficiency of 80 % at a wavelength of <jats:italic>λ</jats:italic> = 4.2 µm, with a narrow full-width-half-maximum of 0.5 µm. By leveraging the hybridization of modes between the Ge and Al layers, the device enables precise spectral filtering. We demonstrate the potential of this metasurface for molecular identification and biosensing applications through numerical simulations and experimental validation. The straightforward fabrication process further highlights the practicality of this approach, paving the way for miniaturized MIR biosensing platforms.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"101 1","pages":""},"PeriodicalIF":6.6000,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nanophotonics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1515/nanoph-2025-0122","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Mid-infrared (MIR) spectroscopy plays a pivotal role in molecular identification and biosensing due to its ability to probe characteristic vibrational fingerprints of biomolecules. Plasmonic nanostructures have been explored for MIR applications but suffer from low efficiencies and broad spectral responses caused by intrinsic ohmic losses. All-dielectric metasurfaces, with low optical losses, offer an attractive alternative; however, their functionality is often restricted to reflection-mode operation. This work introduces a hybrid metal–dielectric metasurface designed to operate in transmission mode, specifically tailored for molecular identification in MIR biosensing applications. The metasurface comprises germanium (Ge) on aluminum (Al) cylinders atop a calcium fluoride (CaF2) substrate, optimized to exhibits a high transmission efficiency of 80 % at a wavelength of λ = 4.2 µm, with a narrow full-width-half-maximum of 0.5 µm. By leveraging the hybridization of modes between the Ge and Al layers, the device enables precise spectral filtering. We demonstrate the potential of this metasurface for molecular identification and biosensing applications through numerical simulations and experimental validation. The straightforward fabrication process further highlights the practicality of this approach, paving the way for miniaturized MIR biosensing platforms.
期刊介绍:
Nanophotonics, published in collaboration with Sciencewise, is a prestigious journal that showcases recent international research results, notable advancements in the field, and innovative applications. It is regarded as one of the leading publications in the realm of nanophotonics and encompasses a range of article types including research articles, selectively invited reviews, letters, and perspectives.
The journal specifically delves into the study of photon interaction with nano-structures, such as carbon nano-tubes, nano metal particles, nano crystals, semiconductor nano dots, photonic crystals, tissue, and DNA. It offers comprehensive coverage of the most up-to-date discoveries, making it an essential resource for physicists, engineers, and material scientists.