Beam combining of quantum cascade laser arrays
                  August 31, 2009
      
      
  
    
                  Journal Article
      
      
  
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      Opt. Express, Vol. 17, No. 18, 31 August 2009, pp. 16216-16224.
      
  
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    Summary
              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.