Pixel-super-resolved lensless on-chip microscopy using a color image sensor

We report a wavelength-scanning-based lensless on-chip microscope using a color CMOS sensor and a matching modified phase retrieval algorithm for pixel super-resolution. Without physically removing the Bayer color filter array positioned on the sensor chip, we demonstrate quantitative phase imaging with a lateral resolution of 615 nm over a wide field-of-view of 51.88 mm² by exploiting the green-channel data from a set of low-resolution holograms captured at various wavelengths. The resulting spatial bandwidth product is 274.3 Megapixels, over 20 times higher than a conventional optical microscope.