title: Temperature-insensitive long-wavelength (λ ≈14 µm) Quantum Cascade lasers with low threshold.
abstract: We demonstrate high-performance, long-wavelength (λ ≈14 µm) Quantum Cascade (QC) lasers based on a diagonal optical transition and a "two-phonon-continuum" depletion scheme in which the lower laser level is depopulated by resonant longitudinal optical phonon scattering followed by scattering to a lower energy level continuum. A 2.8 mm long QC laser shows a low threshold current density of 2.0 kA/cm2, a peak output power of ~336 mW, and a slope efficiency of 375 mW/A, all at 300 K, with a high characteristic temperature T0 ~310 K over a wide temperature range from 240 K to 390 K.
authors.affiliation: Department of Electrical Engineering, Princeton University, Princeton, NJ 08544 USA. xuehuang@princeton.edu
authors.forename: Xue
authors.initials: X
authors.lastname: Huang
authors.forename: William O
authors.initials: WO
authors.lastname: Charles
authors.forename: Claire
authors.initials: C
authors.lastname: Gmachl
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D013696:Temperature