title: Distributed-feedback terahertz quantum-cascade lasers with laterally corrugated metal waveguides.
abstract: We report the demonstration of distributed-feedback terahertz quantum-cascade lasers based on a first-order grating fabricated via a lateral corrugation in a double-sided metal ridge waveguide. The phase of the facet reflection was precisely set by lithographically defined facets by dry etching. Single-mode emission was observed at low to moderate injection currents, although multimode emission was observed far beyond threshold owing to spatial hole burning. Finite-element simulations were used to calculate the modal and threshold characteristics for these devices, with results in good agreement with experiments.
authors.affiliation: Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. bwilliam@mit.edu
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Williams
authors.forename: Sushil
authors.initials: S
authors.lastname: Kumar
authors.forename: Qing
authors.initials: Q
authors.lastname: Hu
authors.forename: John L
authors.initials: JL
authors.lastname: Reno