Chirp-driven control over fast-slow light effects in epsilon-near-zero metamaterials.

Optical applications based on fast and slow light effects force the usage of metamaterials famous for their flexible dispersion properties. In this work, we apply the unique optical nonlocality of metal nanorod-based epsilon-near-zero (ENZ) metamaterials along with the chirp of femtosecond laser pulses for astonishing control of these effects. We demonstrate the switching between the fast and slow light phenomena via the change of the angle of incidence and/or the central wavelength of chirped pulses in the vicinity of metamaterial zero-transmission regime mediated by the ENZ nonlocality. We elucidate that the laser chirp allows one to manipulate and enhance the fast-slow light phenomena.