Nanoparticle Layer Deposition for Plasmonic Tuning of Microstructured Optical Fibers

Abstract Plasmonic nanoparticles with spectral properties in the UV‐to‐near‐IR range have a large potential for the development of innovative optical devices. Similarly, microstructured optical fibers (MOFs) represent a promising platform technology for fully integrated, next‐generation plasmonic devices; therefore, the combination of MOFs and plasmonic nanoparticles would open the way for novel applications, especially in sensing applications. In this Full Paper, a cost‐effective, innovative nanoparticle layer deposition (NLD) technique is demonstrated for the preparation of well‐defined plasmonic layers of selected particles inside the channels of MOFs. This dynamic chemical deposition method utilizes a combination of microfluidics and self‐assembled monolayer (SAM) techniques, leading to a longitudinal homogeneous particle density as long as several meters. By using particles with predefined plasmonic properties, such as the resonance wavelength, fibers with particle‐adequate spectral characteristics can be prepared. The application of such fibers for refractive‐index sensing yields a sensitivity of about 78 nm per refractive index unit (RIU). These novel, plasmonically tuned optical fibers with freely selected, application‐tailored optical properties present extensive possibilities for applications in localized surface plasmon resonance (LSPR) sensing.