Nitrous Oxide (N2O) is an important greenhouse gas, as well as a tracer for stratospheric air mass. We propose to design a miniaturized N2O detector based on direct absorption spectroscopy that is able to be deployed on SIERRA class and Global Hawk UAVs using many of the same functional elements as Aerodyne Research's commercial mini-QCL trace gas instruments. Achieving this will allow for better source attribution of N2O as well as providing an important tool for understanding mixing processes between the troposphere and stratosphere. Specifically, our proposal calls for exploring two designs for a low-volume in-line multipass absorption cells; passive cooling of the laser and instrument electronics, a simplified low-power electronics design and computer, and low-power vacuum pump. The goal for Phase I will be the successful identification, design, and testing of components that can be integrated into a small UAV-compatible instrument packaged during Phase II.