Low Threshold GaSb Based Interband Cascade Lasers in the 3 - 5 µm Wavelength Range

In this paper, we've achieved broad area laser threshold current densities below 300 A/cm² within the entire wavelength range from 3 to 5 μm. These low threshold current densities allow cw-operation of ridge waveguide lasers at room temperature. T₀ values of 50K are typical for ICLs, whereas a record value of 61 K was achieved at 3 μm emission wavelength. A 3 mm long and 15.3 μm wide ridge waveguide laser with one gold coated facet for high reflectivity (HR) and an antireflective (AR) emitted more than 100 mW of optical power in cw-operation at 20°C. Finally, the spectral shift under current induced heating is displayed.