Structured illumination microscopy based on Kramers–Kronig relations for quantitative phase reconstruction

Structured illumination microscopy (SIM) is a widely applied fluorescence super-resolution imaging technique. It can also serve as high-throughput imaging in coherent imaging systems. However, coherent SIM requires additional qualitative/quantitative phase imaging methods to acquire phase information. This paper proposes a structured illumination microscopy technique based on the Kramers-Kronig relations (KK-SIM) that achieves quantitative phase imaging without the need for extra technical assistance and relies solely on the spatial-domain intensity images reconstructed through conventional SIM. KK-SIM utilizes a non-iterative approach to recover intensity into amplitude and phase, maintaining SIM's high acquisition speed and reconstruction efficiency. Our work enables high-throughput quantitative phase imaging using conventional SIM experimental setups and data post-processing, making SIM suitable for label-free, noninvasive dynamic observation.