Coupling Length of Metal/Si Surface Plasmons in a Metal/Insulator/Si Structure Perforated with Periodic Square Hole Arrays

摘要

The zero-order transmission of radiation through a metal/dielectric structure perforated with square hole arrays is strongly enhanced when incident light resonates with surface plasmons (SPs). Surprisingly, when a metal/dielectric double layer, such as Ag/SiO_2, is fabricated on a silicon substrate, the Ag/Si SP mode by coupling Ag and Si across the intermediate dielectric film has been found. The transmission intensity is investigated as a function of the intermediate SiO_2 thickness. The coupling lengths between Ag and Si in order to form the Ag/Si SP mode are determined as well.