TY - JOUR
T1 - Single-mode, tunable distributed-feedback and multiple-wavelength quantum cascade lasers
AU - Gmachl, Claire
AU - Straub, Axel
AU - Colombelli, Raffaele
AU - Capasso, Federico
AU - Sivco, Deborah L.
AU - Sergent, A. Michael
AU - Cho, Alfred Y.
N1 - Funding Information:
Manuscript received January 12, 2002; revised February 26, 2002. This work was supported by DARPA ARO under Contract DAAD19-00-C-0096. The work of A. Straub was supported by the Studienstiftung des Deutschen Volkes. C. Gmachl, R. Colombelli, F. Capasso, D. L. Sivco, and A. Y. Cho are with Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974-1250 USA (e-mail: cg@lucent.com). A. Straub was with Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07074 USA. He is now with the University of New South Wales, Sydney, Australia. A. M. Sergent was with Agere Systems, Murray Hill, NJ 07074 USA. He is now with Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974 USA. Publisher Item Identifier S 0018-9197(02)05020-0.
PY - 2002/6
Y1 - 2002/6
N2 - Single-mode and tunable quantum cascade distributed feedback (QC-DFB) lasers in the wavelength range from 4.5 to 16.5 μm are reviewed. In the case of QC lasers with dielectric waveguides, DFB lasers are fabricated either with a top-grating approach, which is simpler to manufacture, or a buried grating with epitaxial regrowth, which generally has a higher single-mode yield as a result of a larger coupling factor. Long-wavelength QC-DFB lasers based on surface plasmon waveguides use bi-metal gratings for Bragg reflection. Single-mode emission with a side-mode suppression ratio of 30 dB and a tunability (depending on wavelength) of 0.3-1.0 nm/K heat sink temperature or of 20-40 nm/A CW current are customarily achieved. These features together with the potential for high optical power, room-temperature operation, and narrow intrinsic linewidth make QC-DFB lasers prime choices as narrow-band light sources in mid-infrared trace gas sensors. As a result of their unipolar nature and the possibility to serially stack, or "cascade," many active regions, QC lasers also have an intrinsic potential for multiple-wavelength operation in a wide variety of device concepts. Multiple different optical transitions in single active regions stacked in a homogeneous cascade as well as multiple single-wavelength active regions cascaded in various schemes of heterogeneous cascades have been demonstrated. Based upon multiple-wavelength QC lasers, multiple single-mode QC-DFB lasers have been fabricated using sectioned laser cavities with multiple gratings. Adjusting the length of each Bragg-grating section as well the mode-overlap factor by tailoring the heterogeneity of the cascade has lead to a doubly single-mode QC-DFB laser with simultaneous single-mode emission around 5.0 and 7.5 μm and a tunability at each wavelength as expected from equivalent single-wavelength single-mode lasers. Finally, the concept of multiple-wavelength emission was extended to ultrabroad-band emission, with a QC laser that exhibited gain from 5 to 8 μm and simultaneous laser action from 6 to 8 μm.
AB - Single-mode and tunable quantum cascade distributed feedback (QC-DFB) lasers in the wavelength range from 4.5 to 16.5 μm are reviewed. In the case of QC lasers with dielectric waveguides, DFB lasers are fabricated either with a top-grating approach, which is simpler to manufacture, or a buried grating with epitaxial regrowth, which generally has a higher single-mode yield as a result of a larger coupling factor. Long-wavelength QC-DFB lasers based on surface plasmon waveguides use bi-metal gratings for Bragg reflection. Single-mode emission with a side-mode suppression ratio of 30 dB and a tunability (depending on wavelength) of 0.3-1.0 nm/K heat sink temperature or of 20-40 nm/A CW current are customarily achieved. These features together with the potential for high optical power, room-temperature operation, and narrow intrinsic linewidth make QC-DFB lasers prime choices as narrow-band light sources in mid-infrared trace gas sensors. As a result of their unipolar nature and the possibility to serially stack, or "cascade," many active regions, QC lasers also have an intrinsic potential for multiple-wavelength operation in a wide variety of device concepts. Multiple different optical transitions in single active regions stacked in a homogeneous cascade as well as multiple single-wavelength active regions cascaded in various schemes of heterogeneous cascades have been demonstrated. Based upon multiple-wavelength QC lasers, multiple single-mode QC-DFB lasers have been fabricated using sectioned laser cavities with multiple gratings. Adjusting the length of each Bragg-grating section as well the mode-overlap factor by tailoring the heterogeneity of the cascade has lead to a doubly single-mode QC-DFB laser with simultaneous single-mode emission around 5.0 and 7.5 μm and a tunability at each wavelength as expected from equivalent single-wavelength single-mode lasers. Finally, the concept of multiple-wavelength emission was extended to ultrabroad-band emission, with a QC laser that exhibited gain from 5 to 8 μm and simultaneous laser action from 6 to 8 μm.
KW - Distributed feedback laser
KW - Mid-infrared
KW - Multiple-wavelength light source
KW - Quantum cascade laser
KW - Super-continuum generation
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U2 - 10.1109/JQE.2002.1005407
DO - 10.1109/JQE.2002.1005407
M3 - Article
AN - SCOPUS:0036610985
SN - 0018-9197
VL - 38
SP - 569
EP - 581
JO - IEEE Journal of Quantum Electronics
JF - IEEE Journal of Quantum Electronics
IS - 6
ER -