Current dependence of spontaneous carrier lifetimes in GaAs–Ga1-xAlx As double-heterostructure lasers

The spontaneous lifetime of injected carriers in GaAs–Ga_1‐xAl_x As double‐heterostructure lasers is examined in relation to the current injection levels. It is shown that the spontaneous lifetime at threshold is proportional to $J_{\mathrm{th}}^{\text{−1/2}}$ in lasers with a 2×10¹⁷/cm³ Si‐doped active region. From the proportionality constant the effective recombination constant B_eff is estimated to be 9.0×10⁻¹¹ cm³/sec, which agrees quite well with the theoretical value for band‐to‐band transitions.