title: Real-time mid-infrared imaging of living microorganisms.
abstract: The speed and efficiency of quantum cascade laser-based mid-infrared microspectroscopy are demonstrated using two different model organisms as examples. For the slowly moving Amoeba proteus, a quantum cascade laser is tuned over the wavelength range of 7.6 µm to 8.6 µm (wavenumbers 1320 cm(-1) and 1160 cm(-1) , respectively). The recording of a hyperspectral image takes 11.3 s whereby an average signal-to-noise ratio of 29 is achieved. The limits of time resolution are tested by imaging the fast moving Caenorhabditis elegans at a discrete wavenumber of 1265 cm(-1) . Mid-infrared imaging is performed with the 640 × 480 pixel video graphics array (VGA) standard and at a full-frame time resolution of 0.02 s (i.e. well above the most common frame rate standards). An average signal-to-noise ratio of 16 is obtained. To the best of our knowledge, these findings constitute the first mid-infrared imaging of living organisms at VGA standard and video frame rate.
authors.affiliation: Heidelberg University, Kirchhoff-Institute for Physics, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany. katharina.haase@kip.uni-heidelberg.de.
authors.forename: Katharina
authors.initials: K
authors.lastname: Haase
authors.affiliation: Heidelberg University, Kirchhoff-Institute for Physics, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany.
authors.forename: Niels
authors.initials: N
authors.lastname: Kröger-Lui
authors.affiliation: Heidelberg University, Kirchhoff-Institute for Physics, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Pucci
authors.affiliation: Heidelberg University, Kirchhoff-Institute for Physics, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany.
authors.forename: Arthur
authors.initials: A
authors.lastname: Schönhals
authors.affiliation: Heidelberg University, Kirchhoff-Institute for Physics, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Petrich
mesh_terms: D000656:Amoeba; D000818:Animals; D017173:Caenorhabditis elegans; D007259:Infrared Rays; D007834:Lasers; D061848:Optical Imaging / Q000379:methods*; D013997:Time Factors
keywords: hyperspectral imaging; microorganism; mid-infrared; quantum cascade laser; real-time