Sirigu, LorenzoTerazzi, RomainAmanti, Maria. I.Giovannini, MarcellaFaist, JeromeDunbar, L. AndreaHoudre, Romuald2010-11-302010-11-302010-11-30200810.1364/OE.16.005206https://infoscience.epfl.ch/handle/20.500.14299/61457WOS:000255120300007We demonstrate high spectral control from surface emitting THz Quantum Cascade Lasers based on a two-dimensional photonic crystal cavity. The perforated top metallic contact acts as an in plane resonator in a tight double-metal plasmonic waveguide providing a strong optical feedback without needing three-dimensional cavity features. The optical far-field patterns do not exhibit the expected symmetry and the shape of the cavity mode. The difference is attributed to a metal surface plasmon mediated light outcoupling mechanism also responsible for the relatively low extraction efficiency. (C) 2008 Optical Society of America.Metal Wave-Guidestext::journal::journal article::research article