Hyperspectral phase imaging with a spatially matched acousto-optical tunable filter

We report a novel concept of an advanced hyperspectral imaging system based on acousto-optical tunable filters (AOTFs) with optional phase imaging modality. Visualization of phase objects is performed using an additional adjustable liquid crystal amplitude mask. The mask shape is matched with the two-dimensional transfer function of the AOTF enabling bandpass spatial filtering. Label-free phase object visualization is demonstrated with unstained histological sections using diascopic incoherent illumination of a standard inverted light microscope.