Multispectral Mid-Infrared Camera System for Accurate Stand-Off Temperature and Column Density Measurements on Flames.

Accurate measurement of temperature in flames is a challenging problem that has been successfully addressed by hyperspectral imaging. This technique is able to provide maps of not only temperature T (K) but also of column density Q (ppm·m) of the main chemical species. Industrial applications, however, require cheaper instrumentation and faster and simpler data analysis.

Fast Quantification of Air Pollutants by Mid-Infrared Hyperspectral Imaging and Principal Component Analysis.

An imaging Fourier-transform spectrometer in the mid-infrared (1850-6667 cm-1) has been used to acquire transmittance spectra at a resolution of 1 cm-1 of three atmospheric pollutants with known column densities (Q): methane (258 ppm·m), nitrous oxide (107.5 ppm·m) and propane (215 ppm·m). Values of Q and T have been retrieved by fitting them with theoretical spectra generated with parameters from the HITRAN database, based on a radiometric model that takes into account gas absorption and emission, and the instrument lineshape function.

Direct hyperspectral dual-comb gas imaging in the mid-infrared.

In this Letter, we present and experimentally validate the first direct hyperspectral dual-comb gas imaging system operating in the mid-infrared region. This method provides an unmatched combination of super-fine spectral characterization and high temporal resolution without the need for thermal contrast between the target molecules and the background. In a proof-of-concept experiment, the system has allowed us to perform precision hyperspectral imaging of butane in the 3.