Self-calibrated and SNR-enhanced particle holography.

In-line particle holography suffers from speckle noise, and great effort has been made to alleviate it by designing post-processing algorithms. Recently, we proposed a novel approach which mitigates it by increasing the signal-to-noise ratio (SNR). The approach enhances the SNR by combining several holograms captured under different illumination angles. Accurate knowledge of the illumination angles is essential for a high-quality reconstruction, and thus requires system calibration which is often time- and labor-intensive. Here, to eliminate the need for intensive pre-calibration, we propose a self-calibrated approach that estimates the illumination angles directly from experimentally collected holograms without requiring any additional hardware or captured images. We demonstrate our method for correcting the illumination misalignment with both numerical simulation and experimental data.