Femto-Laser Processed Metasurface With Fano Response: Applications to a High Performance Refractometric Sensor

• DOI: 10.1007/s13320-024-0736-y
• Publication Date: 2024-10-22T08:03:23Z
• Authors: Mahmoud H. Elshor...; Alejandro San-Blas; Luis Miguel Sanch...; Santiago M. Olaizola; Jesús del Hoyo; Angela Soria-Garcia; Joaquin Andres-Po...; Verónica Pastor-V...; Javier Alda
• Keywords: Fano plane; Retroreflector; Femto-; Fano resonance

Abstract The practical development of compact modern nanophotonic devices relies on the availability fast and low-cost fabrication techniques applicable to a wide variety materials designs. We have engraved split grating geometry stainless steel using femtosecond laser processing. This structure serves as template fabricate efficient plasmonic sensors, where thick gold layer is grown conformally it. scanning electron microscope (SEM) images confirm generation laser-induced periodic spatial structures. optical reflectance our sensors shows two dips corresponding excitation surface plasmon resonances (SPRs) at different wavelengths. Furthermore, asymmetric shape these spectral responses reveals strong narrow Fano resonance. Our computational electromagnetism models accurately reproduce reflectivity fabricated structure. both simulated structures are fitted model that coherently combines SPRs with broad continuum background caused by diffraction. parameters extracted from fitting, such resonance wavelengths line widths, used evaluate performance device refractometric sensor for liquids. maximum sensitivity figure merit 880 nm/RIU 80 RIU −1 , respectively. Besides design sensing device, its exceeds theoretical classical Kretschmann setup.