Heterogeneously Integrated Active Laser Sensing Platform on Si

We propose to develop highly-sensitive low size, weight, and power (SWaP) chip-scale mid-infrared integrated-optic sensors for trace gas measurements, We will combine Tunable Diode Laser Spectroscopy (TDLAS) detection techniques with narrow-linewidth fast-tuning Distributed Feedback (DFB) Quantum Cascade and Interband Cascade Lasers (QCLs and ICLs) to create a platform for a family of sensors, each able to detect one or more gaseous species of interest. The project focuses on novel integration of mid-IR lasers with detectors and absorption-based waveguided or free-space sensing elements on silicon-based substrates. These structures form optical measurement heads suitable for high-volume production using scalable, low-cost fabrication processes available in forthcoming commercial photonics foundries. Phase I will demonstrate the feasibility of trace gas sensing utilizing a novel hybrid-integration approach where a III/V laser material is bonded onto the silicon-on-silicon nitride-on-insulator (SONOI) material platform. A DFB grating is structured within the SONOI material thus creating a DFB-QCL that is directly coupled to a waveguide, thus facilitating monolithic integration with waveguided evanescent sensing elements and on-chip detectors. The sensor head, when combined with our commercial TDLAS electronics, will form an optical gas analyzer that pairs trace gas sensitivity with molecular specificity resistant to false positives.