By Cnr Ifn
It deals with the development of novel imaging devices for Hyperspectral Imaging. In this class of imaging, one collects, for each element (or pixel) of the image of a scene the complete spectral information, giving rise to a 3D datacube in which two dimensions are the spatial (x,y) coordinates, and the third dimension is frequency or wavelength. Our innovative hyperspectral imaging system is based on Fourier-transform spectroscopy and on the use of an ultrastable common-path birefringent interferometer (TWINS). By coupling the interferometer to an optical microscope, we can acquire wide-field hyperspectral images of various observables: transmission, reflection, fluorescence and Raman. The exceptional delay stability and reproducibility of the birefringent interferometer enables rapid acquisition of Raman maps (∼ 30 minutes for a 250 000 pixel image) with high spatial (<1 μm) and spectral (∼ 23/cm) resolution. The time-domain detection allows us to disentangle fluorescence and Raman signals, which can both be measured separately. The system enables the study of 2D materials, biological samples, nanoplastics, and more. The microscope is also configurable to provide images in the k-space, enabling the novel hyperspectral k-space imaging.
