Fig. 3: Transient electric field measurements.
From: Efficient on-chip terahertz generation and detection with GaN photoconductive emitters
a Schematic illustration of the ultrafast approach that employs the exciton Stark effect to investigate the terahertz pulses that propagate along the waveguide. b Terahertz pulses generated using 1 µW pump at 4 different biases, measured using the scheme outlined in (a). The voltage traces, V(t), start at the applied bias and maintains this value until terahertz pulse arrives at the probe location at around t = 8 ps which initiates a voltage drop. The shaded regions around each time trace correspond to the uncertainty in the field measurements estimated using run-to-run variations in the data. c Using the V(t) traces shown in (b), the average terahertz power is calculated for the initial 3 ps (yellow) or 15 ps (gray) of the pulse. The corresponding η is measured as 34% within the first 3 ps of the pulse and η = 113% within the first 15 ps of the pulse
