title: Beam combining of quantum cascade laser arrays.
abstract: Wavelength beam combining was used to co-propagate beams from 28 elements in an array of distributed-feedback quantum cascade lasers (DFB-QCLs). The beam-quality product of the array, defined as the product of near-field spot size and far-field divergence for the entire array, was improved by a factor of 21 by using wavelength beam combining. To demonstrate the applicability of wavelength beam combined DFB-QCL arrays for remote sensing, we obtained the absorption spectrum of isopropanol at a distance of 6 m from the laser array.
authors.affiliation: Harvard University, School of Engineering and Applied Sciences, Cambridge, MA, USA.
authors.forename: Benjamin G
authors.initials: BG
authors.lastname: Lee
authors.forename: Jan
authors.initials: J
authors.lastname: Kansky
authors.forename: Anish K
authors.initials: AK
authors.lastname: Goyal
authors.forename: Christian
authors.initials: C
authors.lastname: Pflügl
authors.forename: Laurent
authors.initials: L
authors.lastname: Diehl
authors.forename: Mikhail A
authors.initials: MA
authors.lastname: Belkin
authors.forename: Antonio
authors.initials: A
authors.lastname: Sanchez
authors.forename: Federico A
authors.initials: FA
authors.lastname: Capasso