Near-infrared Raman imaging microscope based on fiber-bundle image compression

The design and performance of a near-infrared Raman imaging microscope (NIR IM) is described. This new instrument utilizes fiber-bundle image compressi on (FIC) to collect simultaneously a 3-D Raman spectral imaging data cube, Key NIRIM design features are discussed, including the FIC fiber-bundle, ex citation laser, optical coupling to the microscope and fiber-bundle, hologr aphic filtering, spectrograph imaging requirements, CCD parameters and chem ical image processing, The theoretical collection efficiency and image qual ity of the NIRIM instrument are compared with those of tunable filter and l ine scanning Raman imaging methods. The performance of the NIRIM is demonst rated using a white light image of a bar-target and Raman chemical images o f samples containing fructose-sucrose and Pb(NO3)(2)-K2SO4 microcrystalline mixtures. A Raman image collection time as fast as 1 s (total detector int egration time) is demonstrated, for a 3-D data cube containing 322 image re solution elements and 900 Raman shift wavelengths. Copyright (C) 1999 John Whey & Sons, Ltd.