Josephson tunnelling in [1 0 0]-tilt YBa2Cu3O7-x bicrystal junctions

[1 0 0]-tilt YBa2Cu3O7-x bicrystal junctions have been fabricated and their Josephson behaviour have been studied. Due to high IcRn-values, the ac Josephson effect in the [1 0 0]-tilt junctions has been observed up to the frequency of 5.3 THz. The absorption of Josephson radiation by IR optical phonon mode at the frequency of 4.6 THz in YBa2Cu3O7-x has been found to be reflected in the I-V curve of the [1 0 0]-tilt junctions, thus giving us a possibility to suggest a new kind of near-field THz spectroscopy. The [1 0 0]-tilt bicrystal junctions are very promising both for fundamental study of low-energy excitations in high-Tc superconductors and applications in THz electronics