Excitation of dielectric-loaded surface plasmon polariton observed by using near-field optical microscopy

The excitation of dielectric-loaded surface plasmon polariton (DLSPP) by a CdS nanostripe placed on a Ag layer is observed by using a scanning near-field optical microscopy (SNOM). The spectroscopic redshift of 30 meV of photoluminescence is observed at different positions of the stripe by SNOM and can be explained as the result of Franz-Keldysh effect. Finite difference time domain calculations confirm the observations of the near-field optical images and spectroscopic data. This DLSPP excitation structure is important in the implementation of photonic integrated circuits as well as the optical guiding modes in plasmonic devices. (c) 2008 American Institute of Physics.