Ridge waveguide structure for lattice-matched quantum cascade lasers

The fabrication and investigation of the ridge waveguide structure for a quantum cascade laser on an indium phosphide substrate intended for a wavelength of 4.8 $\mu$m, which corresponds to one of the atmospheric transparency windows, is calculated. The heterostructure is grown by molecular-beam epitaxy and consists of 30 cascades. Post-growth treatment is performed by photolithography using Russian equipment. The fabricated ridge waveguide structure allowed lasing to be attained at the required wavelength at room temperature.