Linewidth broadening factor and relative intensity noise of interband cascade lasers grown on InAs substrate

Interband cascade lasers (ICLs) are energy-efficient mid-infrared light sources that are grown either on the GaSb substrate or on the InAs substrate. While the dynamical characteristics of GaSb-based ICLs have been well explored, those of InAs-based ICLs have not been revealed yet. This work unveils the linewidth broadening factor (LBF) properties and the relative intensity noise (RIN) characteristics of InAs-based ICLs emitting around 4.6 μm, which produce a continuous wave at room temperature. It is found that the LBF of the InAs-based ICLs is about 1.5, which is smaller than that of GaSb-based ICLs, owing to the higher thermal conductivity and the larger optical confinement factor. The RIN of the InAs-based ICLs reaches below −150 dB/Hz at high pump currents, which is comparable to those of GaSb-based ones.