A compact, high numerical aperture imaging Fourier transform spectrometer and its application

This paper describes a compact imaging Fourier transform spectrometer with high numerical aperture. In comparison with other optical arrangements in which extended interferometer paths are required for the inclusion of dispersion compensation optics, this technique utilizes a rudimentary cubic beam splitter based Michelson interferometer with minimal optical path so that the numerical aperture of the system is maximized. Mathematical modelling is presented showing that the fringe distortions caused by the dispersion in the cubic beam splitter can be entirely removed without any loss of the spectral information. An illustration of the power of the technique is given classifying between different plant foliage performed using a Fisher discriminant function based optimal linear filtering.