Laser Light-field Fusion for Wide-field Lensfree On-chip Phase Contrast Microscopy of Nanoparticles

Abstract

Wide-field lensfree on-chip microscopy, which leverages holography principles to capture interferometric light-field encodings without lenses, is an emerging imaging modality with widespread interest given the large field-of-view compared to lens-based techniques. In this study, we introduce the idea of laser light-field fusion for lensfree on-chip phase contrast microscopy for detecting nanoparticles, where interferometric laser light-field encodings acquired using a lensfree, on-chip setup with laser pulsations at different wavelengths are fused to produce marker-free phase contrast images of particles at the nanometer scale. As a proof of concept, we demonstrate, for the first time, a wide-field lensfree on-chip instrument successfully detecting 300 nm particles across a large field-of-view of ~30 mm2 without any specialized or intricate sample preparation, or the use of synthetic aperture- or shift-based techniques.

Complementary Metal-Oxide-Semiconductor-Based Sensing Platform for Trapping, Imaging, and Chemical Characterization of Biological Samples

“…Recent advances in lensless imaging technologies enabled subpixel spatial resolution by employing ptychography, coded aperture correlation holography, and noniterative sub-pixel shifting holography . While such approaches have been successfully applied for imaging of biological samples , and nanoparticles, they require the use of complex image reconstruction algorithms. However, direct on-chip imaging enables high-resolution microscopy with ease of image acquisition and does not require a complicated image reconstruction step. , Previously, our group reported a direct on-chip dark-field microscopy as a new modality in addition to conventional transmission-based imaging modality .…”