Strongly coupled Raman scattering enhancement revealed by scattering-type scanning near-field optical microscopy.

ABSTRACT: Recent advances in near-field technology with an ultrahigh spatial resolution breaking optical diffraction limit, make it possible to further identify surface-enhanced Raman scattering (SERS) enhancement theories, and to monitor the SERS substrates. Here we verify the electromagnetic enhancement mechanism for SERS with a close-up view, using scattering-type scanning near-field optical microscopy. The array of metal-insulator-metal (MIM) subwavelength structures is studied, in which the field enhancement comes from the strong coupling between gap plasmon polariton and surface plasmon polariton modes. The near-field optical measurements reveal that SERS enhancement factor (EF) varies from one MIM subwavelength unit to another in a finite array. Besides the enhancement of isolated unit, the l

SUBMITTER: Qin K 

PROVIDER: S-EPMC11502024 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature