Thanks to their compactness and low-power consumption, Interband Cascade Lasers (ICLs)
are emerging sources for mid-infrared (MIR) molecular sensing below 6 mu m. Understanding
their noise features is of fundamental importance for applications like high-sensitivity
and high-resolution spectroscopy. It could unveil details of their intrinsic physical
behavior and, similarly to what happened for Quantum Cascade Lasers (QCLs), lead to
the development of frequency and phase stabilization techniques for linewidth reduction.
In this manuscript, we discuss the importance of full frequency noise characterization
for ICLs, pointing out the main similarities and differences with respect to QCLs,
and we show preliminary noise measurements. The frequency noise spectrum is analyzed
and discussed, and the laser linewidth over different timescales calculated.
