MOCVD grown quantum cascade lasers (QCLs) have demonstrated about the same level performance as MBE
grown QCLs. With the regrowth capability to fabricate buried heterostructure (BH) waveguides, the QCL output
power has been dramatically increased and that opens the door to many mid-IR (and THz) applications. With the
stable and high growth rate to produce high performance and reliable BH lasers, commercialization of QCLs with
reasonable qualification and affordable price becomes possible. Furthermore with a good gain material and the
etching and regrowth capability, optoelectronic integration can be realized using MOCVD growth techniques. We
compare the MBE and MOCVD growth techniques and discuss important issues on growth rate stabilization and the
control of growth quality at the hetero-interface. We also go over a few growth and integration examples we are
working on that are preferentially done by MOCVD. Finally we describe a detailed QCL BH regrowth study and
discussed how that can be done right.
Slab-coupled waveguide laser was theoretically analyzed by E. A. J. Marcatili  in the 1970's, based on which, we recently demonstrated a high power slab-coupled waveguide laser with buried hetero-structure. The laser lases around 1525.5 nm, with 3.4 μm*4.4 μm (FWHM) spatial mode shape. With improved current blocking mechanism, the output power reaches 326mW per facet, the coupling efficiency to the single mode fiber (SMF) is 80%, the horizontal and vertical far field angles are 10°, 18° respectively. Electron blocking layer will be implemented to improve internal quantum efficiency. Epi-side down bonding will be used to improve heat dissipation and output power.