Recombination without k-selection rules in dense electron-hole plasmas in high-purity GaAs lasers

The low-temperature emission spectra of high-purity GaAs exhibit an intense new emission line at high optical pumping levels, which is due to band-to-band recombination within an electron-hole plasma. The experimentally determined gain spectra of this laser transition are fitted to calculated line-shape curves, which shows that the recombination takes place without k-selection rules.