Wide field-of-view microscopy with Talbot pattern illumination

Abstract

Wide field-of-view (FOV) microscopy is useful for high-throughput applications because of the capability to obtain large amount of information from a single image. One way to implement a wide FOV microscope is to scan the sample with a two-dimensional focus grid. The transmission or reflection of the focal spots can then be used to reconstruct the sample image. This scheme is effectively a parallel scanning optical microscope (SOM), where the FOV depends on the area of the focus grid and the imaging resolution depends on the spot size of the foci. We use the Talbot image of a twodimensional aperture grid as the focus grid and developed a wide FOV microscope. Preliminary experimental results show the capability of our microscope to acquire wide FOV images of US air force target and MCF-7 cancer cell samples. Fluorescence images of fluorescence beads are also acquired. Because the diffraction of incident beam by the aperture grid contains complicated angular frequencies, the focal spots in Talbot pattern cannot be approximated as Gaussian beams as in conventional SOM. We characterized the focal spots in Talbot pattern and studied the evolution of the full width at half maximum (FWHM). We also simulated the SOM imaging under Talbot pattern illumination using the razor blade as the sample objects.