Lensfree Single-Frame Phase Imaging Microscopy Based on Partially Coherent LED-illumination

We propose a single-frame lensfree phase retrieval(SFLFPR) method based on coherence-limited light-emitting diode (LED) illumination. Combining multi-wavelength scanning iteration for broad-spectrum illumination with phase support constraint, SFLFPR corrects resolution loss caused by the temporal coherence of LED, obtaining quantitative phase imaging results. Using only one hologram, our method can retrieve the high signal-to-noise(SNR) phase of the sample and achieve a half-width resolution of 977 nm across a large field-of-view (FOV) of 19.53 mm(2), surpassing 1.41 times the resolution achieved by the conventional single-frame method. We confirmed the effectiveness of this method in quantitative phase imaging (QPI) by measuring various label-free samples including polystyrene microspheres, phase resolution target (PRT) and HeLa cell slices. Considering its fast real-time single-frame imaging capability, our method has a wide range of biological and medical applications.