GURIN, O. V.; DEGTYAREV, A. V.; DUBININ, M. M.; MASLOV, V. A.; MUNTEAN, K. I.; RYABYKH, V. M.; SVYSTUNOV, O. O.; SENYUTA, V. Selection and focusing of higher-order modes in a CW waveguide terahertz laser. Visnyk of V.N. Karazin Kharkiv National University, series “Radio Physics and Electronics”, n. 36, p. 74-86, 28 Jun. 2022.