title: Surface plasmon quantum cascade lasers as terahertz local oscillators.
abstract: We characterize a heterodyne receiver based on a surface-plasmon waveguide quantum cascade laser (QCL) emitting at 2.84 THz as a local oscillator, and an NbN hot electron bolometer as a mixer. We find that the envelope of the far-field pattern of the QCL is diffraction-limited and superimposed onto interference fringes, which are similar to those found in narrow double-metal waveguide QCLs. Compared to the latter, a more directional beam allows for better coupling of the radiation power to the mixer. We obtain a receiver noise temperature of 1050 K when the mixer is at 2 K, which, to our knowledge, is the highest sensitivity reported at frequencies beyond 2.5 THz.
authors.affiliation: Kavli Institute of NanoScience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Hajenius
authors.forename: P
authors.initials: P
authors.lastname: Khosropanah
authors.forename: J N
authors.initials: JN
authors.lastname: Hovenier
authors.forename: J R
authors.initials: JR
authors.lastname: Gao
authors.forename: T M
authors.initials: TM
authors.lastname: Klapwijk
authors.forename: S
authors.initials: S
authors.lastname: Barbieri
authors.forename: S
authors.initials: S
authors.lastname: Dhillon
authors.forename: P
authors.initials: P
authors.lastname: Filloux
authors.forename: C
authors.initials: C
authors.lastname: Sirtori
authors.forename: D A
authors.initials: DA
authors.lastname: Ritchie
authors.forename: H E
authors.initials: HE
authors.lastname: Beere