Open AccessBroadband tuning of continuous wave quantum cascade lasers in long wavelength (> 10μm) range
Author(s) -
Tatsuo Dougakiuchi,
Kazuue Fujita,
Atsushi Sugiyama,
Akio Ito,
Naota Akikusa,
Tadataka Edamura
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.019930
Subject(s) - optics , laser , cascade , lasing threshold , materials science , wavelength , broadband , optoelectronics , quantum cascade laser , continuous wave , physics , chemistry , chromatography
Broadband spectral tuning in the long wavelength range (greater than 10 μm) was demonstrated with an external-cavity quantum cascade laser. The tunable wavelength of the laser ranged from 9.5 to 11.4 μm (176 cm(-1); corresponding to 18% of the center wavelength) in continuous wave (cw) operation at room temperature, without any anti-reflection coating. The gain chip based on the anti-crossed dual-upper-state (DAU) design provided a cw lasing up to 300 K, with a low threshold current density of 2.1 kA/cm2. The highly stable broadband spectral tuning and high laser performance were enabled by the spectrally homogeneous gain profile of the anti-crossed DAU active region.