Dependence of the carrier concentration on the current in mid-infrared injection lasers with quantum wells

The current dependences of spontaneous luminescence in mid-IR injection lasers with InGaAsSb/InAlGaAsSb quantum wells are experimentally studied in the subthreshold and lasing modes. The current dependence of the carrier concentration is determined using the current dependence of the total spontaneous luminescence. A lack of carrier concentration saturation with current in the lasing mode was observed. It is shown that this can be due to carrier heating at low quantum-confinement levels and an increase in light absorption by free holes in the waveguide