Long Distance Propagation of THz Pulses Having 0.4-THz Bandwidth

We measured the atmospheric propagation of ps terahertz (THz) pulses with a 0.4-THz bandwidth through a 186-m and 910-m distance. When the THz pulses were sequentially measured for a distance of 186 and 910 m at the same weather condition, the time variation due to atmospheric turbulence between the two pulses of the 910 m measurement was up to 4 times larger than that between the two pulses of the 186 m measurement due to the propagation distance and water vapor density (WVD) in atmosphere. THz long path studies are necessary to investigate the proposed applications in the atmosphere such as THz communications and monitoring for pollutants and dangerous gases.