Optimization of reconstructed image quality in 3D computational fluorescence microscopy with electrically tunable spatial axial shearing by complex coherence function

We investigate the optimization of reconstructed image quality in a three-dimensional (3D) fluorescence microscopy system based on spatial axial shearing interferometry in incoherent digital holography (IDH), where the axial shear between orthogonal polarization components is electrically controlled using a liquid crystal lens (LCL). The electrically tunable LCL provides dynamic shear adjustment, improving system flexibility and alignment stability. Beyond hardware implementation, we introduce a coherence-guided IDH framework in which fringe visibility serves as a quantitative indicator of interference reliability and depth reconstruction fidelity. Experiments with fluorescent microspheres demonstrate a strong correlation between spatial coherence strength, signal-to-noise ratio, and 3D reconstruction performance. These results highlight the central role of spatial coherence in incoherent holographic fluorescence imaging and establish coherence-guided optimization as an effective strategy for robust and accurate 3D fluorescence reconstruction