High-Resolution Holographic Microscopy Exploiting Speckle-Correlation Scattering Matrix

Using a conventional refraction-based optical lens, it is challenging to achieve both high-resolution imaging and long-working-distance conditions. To increase the numerical aperture of a lens, the working distance should be compensated and vice versa. Here we propose and demonstrate a new concept in optical microscopy that can achieve both high-resolution imaging and long-working-distance conditions by utilizing a scattering layer instead of refractive optics. When light passes through a scattering layer, it creates a unique interference pattern. To retrieve the complex amplitude image from the interference pattern, we utilize a speckle-correlation scattering-matrix method. The proposed method enables holographic microscopy without any lens or external reference beam. Importantly, it allows high-resolution imaging with a long working distance beyond that which a conventional objective lens can achieve. As an experimental verification, we image various microscopic samples and compare their performances with off-axis digital holographic microscopy.