Single-shot quantitative phase microscopy based on color-multiplexed Fourier ptychography

We present a single-shot quantitative phase imaging (QPI) method based on color-multiplexed Fourier ptychographic microscopy (FPM). Three light-emitting diode (LED) elements with respective R/G/B channels in a programmable LED array illuminate the specimen simultaneously, providing triangle oblique illuminations matching the numerical aperture of the objective precisely. A color image sensor records the light transmitted through the specimen, and three monochromatic intensity images at each color channel are then separated and utilized to recover the phase of the specimen. After one-step deconvolution based on the phase contrast transfer function, the obtained initial phase map is further refined by the FPM-based iterative recovery algorithm to overcome pixel-aliasing and improve the phase recovery accuracy. The high-speed, high-throughput QPI capabilities of the proposed approach are demonstrated by imaging HeLa cells mitosis in vitro, achieving a half-pitch resolution of 388 nm across a wide field of view of 1.33  mm² at camera-limited frame rates (50 fps).