Minimization of optical non-linearities in Fourier transform-infrared microspectroscopic imaging

This paper describes the FT-IR microspectroscopic imaging measurements of 5-mu m diameter particles and demonstrates the associated optical non-linearities, due to chromatic aberration and diffraction. FT-IR microscopes with single-element detector use image masking in order to minimize the optical effect due to diffraction. Image masking cannot be used in the focal-plane array detector microscopes. The work presented here demonstrates that, through the application of multivariate curve resolution (MCR), the chemically significant information can be separated from the optical non-linearities, An improvement of the spatial resolution is achieved through the use of multivariate images of individual components, compared to univariate images at long wavelength. (C) 2000 Elsevier Science B.V. All rights reserved.