Jyoti Katyal* Pages 1 - 9 ( 9 )
Objective: The localized surface plasmon resonance (LSPR) and field enhancement of multilayered nanostructure over single and dimer configuration is studied using finite difference time domain (FDTD) method.
Method: In multilayered nanostructure, there exist concentric nanoshells and metallic core which are separated by a dielectric layer. Strong couplings between the core and nanoshell plasmon resonance modes show a shift in LSPR and enhancement in field around nanostructure. The calculation of the electric field enhancement shows a sharp increase in the electric field on the surface of inner core i.e., inside the dielectric layer of Metal-Dielectric-Metal (MDM) structure whereas smaller enhancement on the outer layer of MDM structure is observed.
Result: The Au-Air-Au mono MDM nanostructure shows strong near-field enhancement as compared to bare nanosphere in the infrared region, which have potential applications in surfaceenhanced spectroscopy, whereas Al-Air-Al and Ag-Air-Ag shows potential towards lower wavelength region. On coupling the MDM nanostructure forming a dimer configuration the field enhancement factor increases to 108.
Conclusion: As compared to other nanostructures, MDM nanostructure provides both strong field enhancement and wide wavelength tunability therefore promising for surface enhanced Raman spectroscopy (SERS) applications.
Multilayered nanostructure, Field enhancement, Localized surface plasmon resonance, FDTD
Amity Institute of Applied Science, Amity University, UP 201331