title: Giga-pixel lensfree holographic microscopy and tomography using color image sensors.
abstract: 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 ~0.8, across a field-of-view of ~20.5 mm(2). This constitutes a digital image with ~0.7 Billion effective pixels in both amplitude and phase channels (i.e., ~1.4 Giga-pixels total). Furthermore, by changing the illumination angle (e.g., ± 50°) 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 ~0.35 µm × 0.35 µm × ~2 µm, in x, y and z, respectively, creating an effective voxel size of ~0.03 µm(3) across a sample volume of ~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.
authors.affiliation: Electrical Engineering Department, University of California Los Angeles, Los Angeles, California, United States of America.
authors.forename: Serhan O
authors.initials: SO
authors.lastname: Isikman
authors.forename: Alon
authors.initials: A
authors.lastname: Greenbaum
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Ahmet F
authors.initials: AF
authors.lastname: Coskun
authors.forename: Aydogan
authors.initials: A
authors.lastname: Ozcan
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000033:anatomy & histology; D003116:Color; D006696:Holography / Q000295:instrumentation / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D008853:Microscopy / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D014054:Tomography / Q000295:instrumentation / Q000379:methods*