A Compact and Fast Long-Wave Infrared (LWIR) Spectroscopy System for Aerosol Combustion

We propose developing new instrumentation based on swept-wavelength external cavity quantum cascade lasers (swept-ECQCLs), to acquire physical/chemical data on chemical weapon agent (CWA) and simulant properties in laboratory-scale explosive testing, and to improve/validate computational fluid dynamics (CFD) codes. In Phase I, we demonstrated laboratory measurements of CWA simulant combustion using a swept-ECQCL to measure broadband infrared transmission/absorption spectra through explosive fireballs at a 400 Hz rate and determine fireball temperature and species concentrations versus time. Aerosolized CWA simulants DIMP and TEP were measured and identified unambiguously based on their absorption spectra, and decomposition products ethene and propene were quantified for different explosive test configurations. For Phase II, Opticslah LLC proposes developing the swept-ECQCL instrumentation and analysis algorithms into a hardened prototype, performing extensive laboratory-scale high-explosive testing of the system, and comparing measurements with CFD simulation outputs. The swept-ECQCL instrumentation will provide a versatile diagnostic for high-speed in-situ sensing of CWA simulants in explosive fireballs for immediate applications in CWA-defeat and validation of CFD codes, and future standoff detection with larger-scale explosive testing. The technology will be viable for high-speed chemical sensing applications in additional defense/commercial markets to detect toxic chemicals, perform combustion/engine diagnostics, monitor industrial processes, and more.