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The lensless in-line holographic microscope offers a compact, low-cost, and wide-field solution for microscopic imaging. Instead of using lenses, lensless microscopy relies on diffraction patterns to reconstruct images of the sample. Therefore, coherent light sources such as lasers are typically used to illuminate the sample for reconstruction images. However, lasers will introduce speckle and multiple reflection interference noise, while also being high in cost. As a result, LED illumination sources have been employed in lensless microscopy systems. However, the temporal coherence of LEDs affects the imaging resolution, which results in poor quality of the reconstructed images. In this paper, we propose an iterative twin image removal method based on a single diffraction pattern based on a lensless on-chip microscopy with a partially coherent illumination source. This method combines the wavelength demultiplexing method with positive absorption constraint and phase flipping. It can not only reduce the temporal coherence limitation of broadband light sources but also improve the convergence speed during iteration and provide better support estimation for complexshaped samples, thus improving the quality of reconstructed images. We provide numerical simulations and optical experiments to illustrate the effectiveness of our method. This work helps extend the application of lensless in-line holographic microscopy based on partially coherent light sources in biomedical detection, offering a more convenient and cost-effective option for microscopic imaging.
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