This work theoretically and experimentally investigates the impact of plasmonic and dielectric substrates on the whispering-gallery modes in π-conjugated polymer microspheres. Substrate-dependent quenching and spectral shift of the WGM peaks have been observed. Dielectric substrate quenches the WGMs by frustrated total internal reflection， whereas plasmonic substrate reduces the intensity of WGMs by polarization-dependent excitation of surface plasmons. As for the spectral shift， the trend can be qualitatively explained by the modification of the effective cavity size due to Goos-Hänchen effect around the polymer-substrate contact point.

Implemented by Department of Applied Physics and Chemistry
Date: 2024/12/27