Giga-Pixel Lensfree Holographic Microscopy and Tomography Using Color Image Sensors

We report Giga-pixel lensfree holographic microscopy and tomography using color sensor-arrays such as CMOS imagers that exhibit Bayer color filter patterns. Without physically removing these color filters coated on the sensor chip, we synthesize pixel super-resolved lensfree holograms, which are then reconstructed to achieve,350 nm lateral resolution, corresponding to a numerical aperture of similar to 0.8, across a field-of-view of similar to 20.5 mm(2). This constitutes a digital image with similar to 0.7 Billion effective pixels in both amplitude and phase channels (i.e., similar to 1.4 Giga-pixels total). Furthermore, by changing the illumination angle (e.g., +/- 50 degrees) and scanning a partially-coherent light source across two orthogonal axes, super-resolved images of the same specimen from different viewing angles are created, which are then digitally combined to synthesize tomographic images of the object. Using this dual-axis lensfree tomographic imager running on a color sensor-chip, we achieve a 3D spatial resolution of similar to 0.35 mu mx 0.35 mu m x similar to 2 mu m, in x, y and z, respectively, creating an effective voxel size of similar to 0.03 mu m(3) across a sample volume of similar to 5 mm(3), which is equivalent to.150 Billion voxels. We demonstrate the proof-of-concept of this lensfree optical tomographic microscopy platform on a color CMOS image sensor by creating tomograms of micro-particles as well as a wild-type C. elegans nematode.