Terahertz stimulated emission under the optical resonant excitation of germanium doped with shallow donors

The mechanisms responsible for terahertz stimulated radiation under resonant intracenter excitation of shallow donors in bulk germanium are considered to be the inversion laser mechanism (ILM) and electron stimulated Raman scattering (e-SRS). The e-SRS cross-section was estimated in the case of resonant excitation of odd levels of a shallow arsenic donor in germanium. The output intensity under resonant excitation of germanium doped with arsenic is calculated. It is shown that at an intensity exceeding the threshold for e-SRS, there should be a competition of mechanisms leading to a decrease in the intensity of ILM, which can be detected by the dependence of the output intensity on time.