1-kHz Real-Time Imaging Using a Half-Cycle Terahertz Electromagnetic Pulse

Abstract

Real-time high-speed terahertz (THz) two-dimensional imaging at a frame rate as high as 1 kHz was performed using intense half-cycle THz electromagnetic pulses. The THz source was a 3-cm-gap photoconductive antenna. The distribution of THz electric field was detected by a single optical probe pulse using a high-speed charge–coupled device camera by adopting a phase-sensitive electrooptic detection method. Using the system, we demonstrated imaging of a moving metal object by observing the transmitted beam. The time delay of optical pulses was fixed to probe the THz pulse at the time when the axial THz waveform has the steepest transient, which yields a good image quality. This research opens the window of high-speed imaging in the THz frequency regime.