Full text loading...
(Color online) Schematic of stair-shaped electrodes for THz-ABCD. A pair of parallel aluminum electrodes was separated by 1.5 mm. The electrode width varies from 1 mm to 6 mm with a step of 1 mm. Translation of the electrodes along the y-axis allows for adjustment of the electrode width experienced by the plasma. PMT: photomultiplier tube.
(Color online) Experimental data (red symbols) and simulation (blue curve) for THz field versus electrode width. The upper curve (circles) shows data for a 35-mm-diameter THz beam while the lower curve (boxes) was for 20-mm-diameter THz beam. The black dotted line represents a plane-wave simulation, in which the Guoy phase shifts are ignored. Error bars show the standard deviation of the measured THz signal strength for each electrode width. The two spots on the left (0.5 mm) show the experimental data for wire electrodes.
(Color online) Measured dynamic range, (left scale) and signal-to-noise ratio, (right scale) versus electrode width for 35-mm-diameter THz beam. The insets show a sample measurement of the THz field, the fluctuations of the peak signal (noise curve in black), and the fluctuations of the background (noise curve in red). The THz signal was scanned along the time delay. Fluctuations were measured at a fixed time delay position for 20 s.
(Color online) Measured frequency components of THz signal with electrode width of 2 mm (black line), 4 mm (red dash) and 6 mm (blue dot), respectively. The lower curves are the noise level (measured 2 ps before the THz pulse).
Article metrics loading...