The generation of radiation in 7-8 μm spectral range quantum-cascade lasers with the design of the active region based on a two-phonon resonance design is demonstrated. The wavelength of radiation tuning range under the action of the control voltage was 35 cm-1. The heterostructure of a quantum-cascade laser was grown by molecular beam epitaxy based on a In0.53Ga0.47As/Al0.48In0.52As heteropair, matched by lattice parameter with an InP substrate, and InP layers, which functioned as waveguide claddings.