Speckle spectrum autocorrelation imaging for complex strongly scattering scenarios

Imaging through strongly scattering media noninvasively faces a key challenge: reconstructing the object phase spectrum.Speckle correlation imaging (SCI) effectively reconstructs the amplitude spectrum but struggles with stable and accurate phase spectrum reconstruction, particularly in variable or background-lightinterfered scenarios.In this study, we proposed a speckle spectrum autocorrelation imaging (SSAI) approach for complex strongly scattering scenarios.SSAI employs the spectrum autocorrelation of centroid-aligned speckle images for independent and stable reconstruction of the object phase spectrum, markedly reducing interference from medium dynamics and object motion.Then, SSAI reconstructs the object spectrum by combining the object phase spectrum with the object amplitude spectrum recovered from the speckle autocorrelation.In the experimental validation, we compared SSAI and SCI in reconstructing stationary and moving objects hidden behind dynamic media, both with and without background light interference.SSAI not only exhibits stability and fidelity superior to SCI but also functions in scattering scenarios where SCI fails.Furthermore, SSAI can reconstruct size-scaling objects hidden behind dynamic scattering media with high fidelity, showing significant scalability in complex scenarios.We expect this lensless and noninvasive approach to find widespread applicability in biomedical imaging, astronomical observations, remote sensing, and underwater detection.