Mid-infrared chemical imaging Chemical imaging

a set of stones scanned specim lwir-c hyperspectral imager in thermal infrared range 7.7 μm 12.4 μm. minerals such quartz , feldspar spectra recognizable.

mid-infrared (mir) spectroscopy probes fundamental molecular vibrations, arise in spectral range 2,500-25,000 nm. commercial imaging implementations in mir region employ hyperspectral imagers or fourier transform infrared (ft-ir) interferometers, depending on application. mir absorption bands tend relatively narrow , well-resolved; direct spectral interpretation possible experienced spectroscopist. mir spectroscopy can distinguish subtle changes in chemistry , structure, , used identification of unknown materials. absorptions in spectral range relatively strong; reason, sample presentation important limit amount of material interacting incoming radiation in mir region. data can collected in reflectance, transmission, or emission mode. water strong absorber of mir radiation , wet samples require advanced sampling procedures (such attenuated total reflectance). commercial instruments include point , line mapping, , imaging. mid-infrared chemical imaging can performed nanometer level spatial resolution using atomic force microscope based infrared spectroscopy (afm-ir).

remote chemical imaging of simultaneous release of sf6 , nh3 @ 1.5km using telops hyper-cam imaging spectrometer

for types of mir microscope, see microscopy#infrared microscopy. atmospheric windows in infrared spectrum employed perform chemical imaging remotely. in these spectral regions atmospheric gases (mainly water , co2) present low absorption , allow infrared viewing on kilometer distances. target molecules can viewed using selective absorption/emission processes described above. example of chemical imaging of simultaneous release of sf6 , nh3 shown in image.