Room temperature continuous wave operation of quantum cascade lasers

Fabrication of the laser structures relied on molecular beam epitaxy for the growth of the waveguide core (lower waveguide layer, active region and upper waveguide layer). Metalorganic vapor phase epitaxy was used for the growth of the InP top cladding layer and for the re-growth of the buried heterostructure. As shown schematically between the two waveguide layers comprised 35 repetitions of alternating un-doped 4 QW active regions.