  We propose a novel kind of the low-loss THz Waveguide Bragg Grating (TWBG)
fabricated using plasmonic two-wire waveguide and a micromachined paper grating
for potential applications in THz communications. Two TWBGs were fabricated
with different periods and lengths. Transmission spectra of these TWBGs show 17
dB loss and 14 dB loss in the middle of their respective stop bands at 0.637
THz and 0.369 THz. Insertion loss of 1-4 dB in the whole 0.1-0.7 THz region was
also measured. Finally, TWBG modal dispersion relation, modal loss and field
distributions were studied numerically, and low-loss, high coupling efficiency
operation of TWBGs was confirmed.
