Extended flexible terahertz waveguide with low attenuation

The possibility of fabricating a flexible extended terahertz waveguide with low losses, which has a hollow core and a reflective shell of eight polypropylene capillaries located in a common shell with an outer diameter of 7.5 mm, has been demonstrated. The transmittance of terahertz pulses with frequencies of 2.3–2.8 THz through a waveguide (including a bended one, $R_{bent}\sim$ 60 cm) longer than 3 m with an attenuation of 5 dB/m has been experimentally confirmed.