A test target for estimating the resolution of a holographic microscope

A method for testing the resolution of a holographic microscope with a set of in-house test targets is presented. The test targets are made of calibrated microparticles mixed in clear polyurethane medium and sealed between two glass plates. The depth range inside the target that can be imaged with adequate lateral resolution with different holographic microscope setups is demonstrated by studying resolvability of the microparticles from the reconstructed hologram images using Sparrow's definition for the resolution limit. In addition, the effect of different particle concentrations to image signal-to-noise-ratio is evaluated.