We report on the experimental evidence for terahertz (THz) lasing of boron-doped strained Si1−xGex quantum-well structures. The lasing arises under strong electric fields (300–1500 V/cm) applied parallel to interfaces. The spectrum of THz stimulated emission is presented showing the lasing wavelength near 100 μm and the modal structure caused by a resonator. The mechanism of population inversion is based on the formation of resonant acceptor states in strained SiGe layer.

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An intense THz emission was observed from strained SiGe/Si quantum-well structures under strong pulsed electric field. The p-type structures were MBE-grown on n-type Si substrates and δ-doped with boron. Lines with wavelengths near 100 microns were observed in the emission spectrum. The modal structure in the spectrum gave evidence for the stimulated nature of the emission. The origin of the THz emission was attributed to intra-centre optical transitions between resonant and localized boron levels.

Stimulated emission of far‐infrared radiation from uniaxially compressed p‐Ge in strong electric fields is shown to be due to population inversion of strain‐split acceptor levels. A peak corresponding to the optical transitions between split‐off and ground acceptor states is found in the spectrum of stimulated emission. A strong frequency tuning by stress due to the pressure dependence of the energy splitting of these states is obtained. The inversion takes place as the split‐off acceptor state is in the valence band continuum.