The interaction of focused light with a biological sample depends on many interacting optical phenomena including absorption, diffraction, scattering, refraction and dispersion. An idealized infrared microspectroscopy system measures the sample absorption as a function of position, however the other phenomena can also contribute data features. While these contributions can be regarded as artifacts in many cases, it may also be possible to exploit their presence. Through exploration of the interaction of light with matter, we are engaged in the optimization of existing microspectroscopy techniques and the development of novel modalities.

Figure: A simulation showing the interaction of focused light with the edge of an absorbing sample (boundary indicated by the solid line) mounted on a barium fluoride substrate (boundary indicated by the dashed line). A numerical aperture of 0.5 is used to focus light with a wavelength of 6 microns.