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HgCdTe-based heterostructures with quantum wells (QWs) are a promising material for semiconductor lasers in the atmospheric transparency window (3–5 μm) thanks to the possibility of suppressing Auger recombination due to the no-parabolic law of carrier dispersion. In this work, we analyze the thresholds of stimulated emission (SE) under optical pumping from heterostructures with a different number of QWs in the active region of the structure. Total losses in structures are determined from the comparison of thresholds for the different number of QWs in the active region. It is shown that, thanks to the increased modal gain, a higher number of QWs results in lower threshold pumping intensity and, consequently, higher temperature of SE. These results indicate that improvements to the modal gain can result in a moderate uplift in the temperature of SE from mid-infrared HgCdTe-based heterostructures. On the other hand, at a high enough QW count threshold, the intensity no longer depends on the number of the QWs and is determined by the transparency concentration of a single QW. [ABSTRACT FROM AUTHOR]

Heterostructures with thin Hg(Cd)Te/CdHgTe quantum wells (QWs) are attractive for the development of mid-infrared interband lasers. Of particular interest are room-temperature operating emitters for the short-wavelength infrared range (SWIR, typically defined as 1.7–3 μm). In this work, we report on the observation of stimulated emission (SE) in the 2.65–2.75 µm wavelength range at room temperature in an optically pumped HgCdTe QW laser heterostructure. We study a series of three samples with lengths ranging from 2.5 to 7 mm and discuss the effects related to the non-uniformity of the excitation beam profile. SE threshold intensity and the magnitude of pump-induced carrier heating are found to be effectively dependent on the chip size, which should be accounted for in possible designs of HgCdTe-based optical converters. We also pay attention to the problem of active medium engineering in order to push the SE wavelength towards the 3–5 µm atmospheric window and to lower the SE threshold. [ABSTRACT FROM AUTHOR]

In this work we calculate and analyze modal gain for terahertz lasers based on HgCdTe heterostructures with quantum wells (QWs) taking into account the symmetry-enforced light hole-heavy hole mixing at the quantum well interfaces. We have found that modal gain for a structure with 5 HgTe QWs of the 5.2 nm width can be 33 cm−1 at 9 THz. [ABSTRACT FROM AUTHOR]

Heterostructures with quantum wells (QWs) based on HgCdTe are promising systems for making compact semiconductor sources of the mid-infrared range. This range has paramount practical importance due to the presence of absorption lines of common pollutant gases. Stimulated emission (SE) from HgCdTe heterostructures has been observed previously at the wavelengths up to 3.7 μm at temperatures above 200 K, but the optimal design of the QW is still debated. We present the spectra of SE from a HgCdTe-based heterostructure obtained at room temperature (RT). We investigate the effect of optical excitation wavelength on the characteristics of SE and discuss possible routes toward improving the design of the active region of the sample. Obtained results demonstrate that HgCdTe heterostructures can be used for the creation of lasers operating at RT at the wavelengths in the vicinity of at least 2.5 μm. [ABSTRACT FROM AUTHOR]