QCL-based standoff and proximal chemical detectors
| Autor: | Shing Chang, Julia R. Dupuis, Bogdan R. Cosofret, William J. Marinelli, Daisei Konno, Mark G. Allen, Joel M. Hensley, Phillip A. Mulhall, Thomas Schmit |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Physics::Instrumentation and Detectors business.industry Emphasis (telecommunications) Detector Physics::Optics 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Noise (electronics) Signal law.invention 010309 optics Speckle pattern Optics law 0103 physical sciences Clutter Specular reflection 0210 nano-technology Quantum cascade laser business |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.2223038 |
| Popis: | The development of two longwave infrared quantum cascade laser (QCL) based surface contaminant detection platforms supporting government programs will be discussed. The detection platforms utilize reflectance spectroscopy with application to optically thick and thin materials including solid and liquid phase chemical warfare agents, toxic industrial chemicals and materials, and explosives. Operation at standoff (10s of m) and proximal (1 m) ranges will be reviewed with consideration given to the spectral signatures contained in the specular and diffusely reflected components of the signal. The platforms comprise two variants: Variant 1 employs a spectrally tunable QCL source with a broadband imaging detector, and Variant 2 employs an ensemble of broadband QCLs with a spectrally selective detector. Each variant employs a version of the Adaptive Cosine Estimator for detection and discrimination in high clutter environments. Detection limits of 5 μg/cm2 have been achieved through speckle reduction methods enabling detector noise limited performance. Design considerations for QCL-based standoff and proximal surface contaminant detectors are discussed with specific emphasis on speckle-mitigated and detector noise limited performance sufficient for accurate detection and discrimination regardless of the surface coverage morphology or underlying surface reflectivity. Prototype sensors and developmental test results will be reviewed for a range of application scenarios. Future development and transition plans for the QCL-based surface detector platforms are discussed. |
| Databáze: | OpenAIRE |
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