Artifactless lensfree coherent microscopy with quasi-three-dimensional scanning

We propose a quasi-three-dimensional scheme to solve imaging artifacts from laser source for lensfree holographic imaging. The scheme includes three steps: background noise removal, image alignment and twin-image elimination. The sample moves along the lateral direction and the imaging sensor is sequentially placed in different axial distances for data record. With this volume data, the artifacts of the laser source can be effectively mitigated. The experiments show that a pixel-level imaging resolution (1.55 μm) over the field-of-view larger than 20 mm2 can be achieved. The experiments of biological samples, including kidney and intestine pathology slides of rats, validate that this technique can realize dramatic image contrast and resolution enhancements, compared to the conventional lensfree holographic methods. Our work provides a new framework to suppress laser source artifacts for holographic imaging.