Adjustable ultrafast response in hyperbolic metamaterials through double resonances

Abstract

Active control of the ultrafast nonlinear optical response in plasmonic nanostructures is essential for the applications of nano-photonics. However, the optical response of noble metal is hindered by the electron dynamics. Here, we demonstrate that the nonlinear absorption properties of silver nanorod arrays could be modulated in the sub-picosecond range by adjusting the incident angle of light. The pump-probe experiment confirmed the response time can be modulated from 2.439 ps to 413 fs by changing the incident angle. Further simulation indicated that the origin of the modulation is the combined effect of the surface plasmon resonance and epsilon-near-zero resonance supported by the samples. Electron temperature shows different effects on the two resonances, leading to the change in the recovery rate of the transmittance during the decrease of the electron temperature. The contributions of the two resonances to nonlinear absorption were presented respectively. The conditions for controlling the relaxation time via multiple resonances were also proposed.

Nonlinearly tunable extraordinary optical transmission in a hybird metamaterial

“…The strong local field generated by resonance makes the nonlinear effect of ceramic cuboid more obvious, which can be used to realize nonlinear tuning of the EOT behavior. Metamaterials with tunability make their functions richer and the working frequency range wider, and may provide more flexible [58][59][60]. Therefore, the proposed nonlinear EOT metamaterials with simultaneous modulation of transmission amplitude and working frequency is of good importance in the research of sensors and tunable metamaterials.…”