Rapid hyperspectral imaging in the mid-infrared

Despite the successes of mid-infrared hyperspectral imaging in a research environment, progress in the migration of technology into the day-to-day clinical application is slow. Clinical acceptance may be improved if the spectroscopy would be faster and the infrared microscopes available at lower cost. Here we present first results of a fast, multi-scale mid-infrared microscopy setup which allows for the investigation of 10.6x11.7 mm(2) and 2.8x3.1mm(2) fields of view with a resolution of 23.0 similar to 3.5 mu m and 9.4 similar to 1.8 mu m, respectively. Tunable quantum cascade lasers in the wavenumber ranges of 1030-1090 cm-(1) and 1160-1320 cm-(1) serve as light sources. A vapor cell is used as a frequency reference during the rapid scanning. As far as the imaging is concerned, it is the high spectral power density of the quantum cascade laser which enables the use of a microbolometer array while still obtaining reasonable signal-to-noise ratios on each pixel. Hyperspectral images are taken in times which can be as low as 52s for the overall image acquisition including referencing.