Multiplexed Integrated Cavity Output Spectrometer Driven by Quantum Cascade Laser Arrays

We propose to develop a compact, broadband trace-gas measurement instrument that leverages quantum cascade laser (QCL) array technology with cavity-enhanced absorption techniques. Our goal is to achieve high-sensitivity, multiplexed detection of multiple trace gases—including NO, NO₂, O₃, CH₂O, CO, CH₄, and others—within a single, small-footprint system. By exploiting the broad spectral coverage offered by QCL arrays, we will optimize real-time measurements at parts-per-billion (ppb) or even parts-per-trillion (ppt) levels. The proposed design will be tailored for use on small aircraft, uncrewed aerial vehicles (UAVs), and high-altitude balloon platforms. In Phase 1, we will demonstrate the feasibility and benefits of integrating our DFB QCL array sources with cavity-enhanced absorption spectroscopy in a low-SWAP system for highly sensitive and selective multi-species detection. This includes demonstrating broadband operation and multiplexing methods. We expect to reach TRL 4 at the end of Phase I. Successful prototype demonstration and design work will position the technology for further optimization and maturation in Phase II. At the end of Phase II, we will deliver a TRL 6 flight-ready sensor system that addresses the specific airborne and ground-based trace-gas measurement needs outlined by NASA’s Earth Science Division.