Monolithic Integrated-Optic TDLAS Sensors and Networks

Physical Sciences Inc. (PSI) proposes to develop prototype chip-scale low-power integrated optic gas-phase chemical sensors, based on infrared Tunable Diode Laser Absorption Spectroscopy (TDLAS). TDLAS is able to sense many TICs and CWAs with high sensitivity and selectivity, and low false alarm rate. Each envisioned device will sense one targeted chemical; several devices working in tandem will sense several chemicals. Novel gas sensing elements using solid-state optical waveguides will permit monolithic integration of a laser source, sampling section, and detector on a semiconductor materials system substrate. Use of semiconductor fabrication and assembly techniques will enable low-cost mass production, so that many hundreds or thousands of such sensors can be distributed cost-effectively over a wide area of interest and communicate among each other via a wireless network. By the completion of Phase III, these miniature sensors will be configured in cellphone-size packages making them rugged enough for dropping from an airplane and operable for at least several days when powered by self-contained batteries. Phase I will evaluate a novel passively-cooled mid-infrared quantum cascade laser source that is a key enabling component, and will quantify expected detection limits.