Mid-IR FSO Transmission with Directly Modulated QCLs

We outline our recent experimental studies on free-space optical (FSO) communications enabled by directly modulated quantum cascade lasers (DM-QCL) operating in the mid-wave infrared (MWIR, 3–5 μm) and long-wave infrared (LWIR, 8–12 μm) regions. Our research compares the performance of unipolar quantum optoelectronic (UQO) devices, including the QCL, and various detector types, such as quantum cascade detectors (QCD) and quantum well-infrared photodetectors (QWIP), each with distinct characteristics. In the last section, we get into the FSO experimental setup and reported results in the atmospheric windows.