High-performance distributed feedback quantum cascade lasers grown by metalorganic vapor phase epitaxy

We report the operation of distributed feedback quantum cascade lasers, grown by metalorganic vapor phase epitaxy. Single-mode laser emission at λ∼10.3μm and λ∼7.8μm is observed from two different samples, with 300 K threshold current densities of Jth∼3 and ∼2.4kAcm−2, respectively. Structural investigation by x-ray diffraction and transmission electron microscopy, and the close correlation between the predicted and observed emission wavelengths indicate exceptional control of the layer thicknesses, including ultrathin (∼8Å) barrier layers in the active region. These results confirm metalorganic vapor phase epitaxy as a viable technology for the growth of high-performance quantum cascade lasers.