Inverted distributions of hot holes in uniaxially stressed germanium

Abstract

Compressive stress is found to improve the characteristics of all types of hot hole masers and lasers in p-Ge. Effects of the uniaxial stress of p-Ge crystal on the FIR emission in both E 11 Hand E l H fields are discussed.Mechanisms of the influence of uniaxial stress on the powlation inversion and the stimulated emission of hot holes are revealed.Dynamic heating of the charge carriers in p-Ge in strong electric and magnetic fields (streaming) is known to result in the population inversion and in the stimulated emission at different optical transitions of hot holes in the FIR region (see, for example, [l]). The uniaxial compressive stress splits the top of the valence band at p = 0 A = 4-6meVkbar-', thus affecting the hole dynamics and scattering processes in E, H fields. In the negative cyclotron mass (NCM) maser the effect of the uniaxial stress seems to result directly from the valence band splitting eliminating the band warping and the negative masses at 8 < A/2 << ho, (see figure 1) and diminishing the density

Effect of uniaxial stress on gallium, beryllium, and copper-doped germanium hole population inversion lasers

“…In the papers of Gavrilenko et a1 the laser zone is not very large to begin with and does not come close to the theoretical limits. [32,33] This is probably due to a high dopant cornpensation level leading to significant ionized impurity scattering, which shortens the light hole lifetime and decreases the population inversion.…”

Generation of strong short coherent terahertz pulses in gases and solids using quantum coherence

“…THz pulses with ns durations were achieved in THz semiconductor lasers (quantum cascade lasers, p-Ge and n-Si lasers [19,20,21,22,23], limited by the need for cryogenic cooling).…”

“…In p-Ge lasers [20,21,22], in the mode-lock regime, 20 ps-short pulse durations have been achieved with peak power up to a few Watts in a few-µs train of pulses.…”