Accession Number : AD1040498

Title :   Dual Optical Comb LWIR Source and Sensor

Descriptive Note : Technical Report,28 Sep 2015,28 Sep 2017

Corporate Author : Physical Sciences Inc. Andover United States

Personal Author(s) : Hensley,Joel M ; Brown,Justin M ; Allen,Mark G ; Jouy,Pierre ; Faist,Jerome ; Geiser,Markus ; Allmendinger,Pitt ; Mangold,Markus ; Hugi,Andreas

Full Text :

Report Date : 12 Oct 2017

Pagination or Media Count : 92

Abstract : In this program we developed a compact dual-optical frequency comb (OFC) sensor for standoff detection of national security relevant compounds. These compounds are primarily solids at room temperature and consequently have low vapor pressure. In realistic application scenarios these materials are found on common diffusely reflective Because the target materials have their strongest spectral signatures in the longwave infrared (LWIR) regime, our OFC sources are based on dispersion compensated quantum cascade lasers (QCLs) in the 8 to 12 micron regime. The lasers emit about 1W of optical power under cw operation near room temperature and produce combs with optical bandwidths exceeding 100 wavenumbers. We developed processing algorithms for reducing the high bandwidth multi-heterodyne data stream into the desired spectral information with up to 0.3 cm-1 resolution and optimizing the signal to noise ratio. Finally, we tested a prototype dual-comb system against diffusely scattering surfaces at standoff distances up to 1 meter and demonstrated spectral discrimination at the few microgram mass loading level, a relevant metric for national security needs.

Descriptors :   detection , quantum cascade lasers , SPECTROSCOPY , LONGWAVELENGTH INFRARED RADIATION , optics , lasers , scattering , algorithms , acquisition , absorption spectra , frequency domain , wave mixing , national security

Subject Categories : Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE