Abstract:
In two waveguide heterostructures with quantum-well arrays of Hg$_{0.892}$Cd$_{0.108}$Te/Cd$_{0.63}$Hg$_{0.37}$Te with a thickness of 6.1 nm and Hg$_{0.895}$Cd$_{0.105}$Te/Cd$_{0.66}$Hg$_{0.34}$Te with a thickness of 7.4 nm, stimulated emission is first obtained at wavelengths of 10.3 and 14 $\mu$m under continuous optical excitation at 8 K. It is shown that, due to the presence of Cd in the quantum wells, the effect of fluctuations in the thickness of the quantum wells on the energy of interband transitions in it decreases, which can ultimately cause a significant decrease in the threshold intensity for stimulated emission.