Observation of ultra-narrow band plasmon induced transparency based on large-area hybrid plasmon-waveguide systems

We report the observation of an ultra-narrow band plasmon induced transparency resonance which is realized in a large area hybrid plasmon-waveguide system consisting of a gold nanowire array embedded in a slab waveguide. Due to the destructive interference between optical modes supported by the hybrid system, an ultra-narrow plasmon induced transparency resonance with a bandwidth of 8 nm at the wavelength of 966 nm was obtained (i.e., ∼1/120 of the peak wavelength at the incident angle of 60°). The group velocity is estimated to be ∼76, which is promising for miniaturized slow-light components.