Microstructured sapphire shaped crystals for anitiresonant and bandgap terahertz waveguiding G.M. Katyba, N.V. Chernomyrdin, K.I. Zaytsev and V.N. Kurlov EPJ Web Conf., 195 (2018) 09003 Published online: 23 November 2018 DOI: 10.1051/epjconf/201819509003