Ultrafast Frequency-Shift Dynamics at Temporal Boundary Induced by Structural-Dispersion Switching of Waveguides

We experimentally demonstrate the observation of a frequency-shift dynamics at temporal boundary in terahertz (THz) region relying on scheme that controls structural dispersion metal-semiconductor waveguide. Ultrafast structural-dispersion switching is achieved within subpicosecond timescale by illuminating waveguide surface with an optical pump pulse during propagation THz Owing to relatively high conversion efficiency, up 23%, under condition frequency shift sufficiently larger than bandwidth incident pulse, rapid variation around directly observed time domain.