Silver/polystyrene-coated hollow glass waveguides for the transmission of terahertz radiation

We have applied techniques developed for IR waveguides to fabricate Ag/polystyrene (PS) -coated hollow glass waveguides (HGWs) for transmission of terahertz radiation. A loss of $0.95\mathrm{dB}∕\mathrm{m}$ at $119\mu \mathrm{m}$ $\left(2.5\mathrm{THz}\right)$ was obtained for a $2\mathrm{mm}$ bore, $90\mathrm{cm}$ long Ag/PS HGW. We found that TE modes are supported in HGWs with thin PS films, while hybrid (HE) modes dominate when PS film thickness increases. The lowest losses are obtained for the thicker PS films and the propagation of the HE modes.