Vortex beam dynamic speckle interference microscopy

We proposed vortex beam dynamic speckle interference microscopy (VSIM), a novel, to our knowledge, imaging technique that combines dynamic speckle illumination and common-path phase-shifting interferometry for high-resolution quantitative phase imaging. By exploiting the angular properties of perfect optical vortex beams, VSIM generates a refined speckle pattern, providing clear benefits compared to traditional coherent imaging systems. Experimental validation demonstrates that VSIM improves spatial resolution by 1.39-fold and enhances the signal-to-noise ratio (SNR) from 16.4 dB to 34.3 dB. The proposed method achieved phase modulation between the scattered light from the sample and the unscattered reference light in a robust common-path configuration, which circumvents the stringent requirements of spatial correlation in speckle field interference and effectively mitigates the effects of environmental disturbances.This approach enables high-resolution, noninvasive, and label-free phase retrieval, establishing VSIM as a reliable tool for biomedical imaging, as demonstrated with red blood cells (RBCs) and A549 cells in this paper.