Fano resonance of nanoparticles embedded in Fabry-Perot cavities.

We present an optical structure, which consists of metal nanoparticles embedded in Fabry-Perot (F-P) cavity, to investigate the Fano resonance, which originates from the interaction between F-P mode and the plasmon modes supported by the nanoparticles. The coupling system is modeled theoretically by coupled-mode theory in time domain and the transmission properties are demonstrated numerically by the finite-difference time-domain method. The charge distribution features of the nanoparticle plasmon modes are further characterized by using boundary integral equation technology. Results show that the F-P modes can be used to active the optical inactive surface plasmon modes by breaking the mode symmetry.