Lens-free inline holographic microscopy with numerical correction of layers with different refractive index

Abstract

Digital inline holographic microscopy is applied for lens-free imaging with high lateral resolution. Microfluidic chambers for the imaging of cells in water-like or native solutions, e.g., thick layers of glass and other materials with different refractive index, cause aberrations that limit the spatial resolution and change the magnification scale. In this Letter, a fast reconstruction technique considering parallel layer systems of different refractive indices is presented. In the experiments, properly scaled images of microbeads and red human blood cells with an optical resolution corresponding to a numerical aperture of about 0.62 were reconstructed.