High-performance GaSb-based interband cascade lasers emitting at 4.7 µm grown on GaAs and Si substrates

We successfully fabricated interband cascade lasers (ICLs) emitting at 4.7 µm on GaSb, GaAs, and Si substrates, demonstrating threshold current densities between 212 and 288 A/cm 2 in pulsed operation at room temperature. While ICLs on mismatched substrates exhibited higher series resistance, they showed lower thermal resistance, suggesting that reducing series resistance could improve device performance. All lasers operated in continuous-wave mode up to 30°C, and aging tests on ICLs grown on Si over 500 hours showed no performance degradation. These results confirm the tolerance of ICLs to dislocations, even at longer wavelengths.