Method for estimating and analyzing the resolution of digital holographic microscopy

This study presents a comprehensive numerical approach for evaluating and analyzing the resolution of digital holographic microscopes. The analysis focuses on five key factors that have the greatest impact on image reconstruction quality: object-to-sensor distance, temporal and spatial coherence of the illumination source, physical pixel size of the detector, and the optical field of view (FOV). For each of these factors, numerical modeling algorithms were developed and integrated into a unified software platform that enables systematic analysis without the need for physical experiments. This is particularly relevant for the development of compact and low-cost digital holographic microscopes. A wave propagation model based on the angular spectrum method was implemented, and simulations were conducted for a typical holographic microscope configuration. Validation of the results and resolution assessment were carried out using the USAF 1951 resolution target. It was found that the most significant limitations are associated with pixel size, object-to-sensor distance, and the size of the reconstruction area. Coherence properties of the source also affect resolution but can often be compensated for during the design phase. It is demonstrated that the developed algorithm enables preliminary estimation of the theoretical resolution limit for a given system configuration and identification of dominant constraints. The scientific novelty of this work lies in the integration of all major resolution-related factors into a single computational environment, enabling numerical optimization of digital holographic microscope parameters during the design stage. The proposed approach can be applied in the development of portable holographic microscopes for applications in biomedicine, microplastic monitoring, and other practical domains.