Pump-probe ultrashort pulse modulation in an AZO/ZnO metamaterial at the epsilon near zero spectral point

Abstract

Ultrashort pulse propagation at the epsilon-near-zero spectral point is numerically investigated using the finite difference time-domain technique for the pump-probe experiment. Free carriers’ population dynamics in the conduction band for large intensities of the pump pulse and the transient response for rapidly varying pulses in two-level media are calculated. The auxiliary differential equation finite-difference time domain method was used to numerically investigate ultrashort probe pulse propagation in 300 nm of the AZO/ZnO metamaterial. Results show a dramatic change in shape for the probe pulse modulated using pump pulses of various duration (100-500 fs) and amplitude (106−1010 V/m).