Hyperspectral quantitative phase imaging
Daniel Claus (Institut für Technische Optik, Universität Stuttgart, Germany)
The possibility to combine digital holography, a coherent imaging technique, with a broadband light source, while recovering its spectral signature, will be demonstrated. Not only the amplitude information but also the phase information will be recovered. The setup can therefore be configured in a lensless manner, which enables the application of a compact setup with continuously adjustable numerical aperture NA (linear relationship between NA and recording distance). The phase information can furthermore be used for biomedical applications, such as visualizing transparent samples and discriminating between different types of tissue, and for optical metrology applications, to obtain information about the topography of a sample. Besides the traditional white light interferometry approach using the coherence envelope, the topography of a sample can likewise be obtained using the dual wavelength method, which due to the large amount of spectral frequencies available in spectrally resolved holography can be applied multiple times. In that the the measurement uncertainty be reduced. The amplitude information can be employed to retrieve wavelength specific information about an object, which is demonstrated on two dimensional colourimetry, where the recovered spectral information for each pixel is weighted by the eyes spectral response and then converted into RGB colour information.