Compact, Field-Portable Lens-free Microscope using Superresolution Spatio-Spectral Light-field Fusion

Abstract

We present a compact, field-portable lens-free microscope basedon the principle of spatio-spectral light-field fusion. This is the firsttime a device of this kind has been introduced whereby both superresolutionand signal-to-noise ratio are enhanced via the marriageof synthetic aperture imaging and spectral light-field fusionholography, culminating in a system that is self-contained and fieldportablewhile achieving high resolution, contrast, strong signal fidelity,and ultra-wide field-of-view. The active spatio-spectral illuminationis accomplished in the presented microscope by arranginga series of pulsing LEDs emitting at different spectral wavelengthsin a specific spatial formation. To demonstrate the performance ofthe presented microscope, the system was used to observe twohistology samples: a bovine lung, and corn stem. The imaging resultsdemonstrate the ultra-wide field-of-view advantage of the presentedmicroscope over any other system of its kind, thus enablingfor acquisition of the entire sample without the need for scanning,while producing high-resolution, high-contrast microscopy images(168 megapixels in the current system) that makes it well-suited forscientific and clinical examinations.

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

“…Wide-field lensfree on-chip microscopy, where holography principles are used to capture interferometric light-field encodings without lenses, has become an interesting pathway toward addressing the shortcomings of lens-based techniques2345678910111213141516171819202122. At the core, these lensfree on-chip instruments are conceptually simple and offer extremely large FOV in comparison to lens-based instruments.…”

“…Synthetic aperture- or lateral shift-based techniques789112324 have been proposed for improving resolution, though such techniques tend to increase the hardware complexity and decrease performance tolerance of the instrument. More recently, multi-wavelength illumination-based techniques1720212225 have also showed considerable promise for improving resolution.…”

“…Inspired by our earlier, preliminary exploration into spectral light-field fusion202122, laser light-field fusion phase contrast microscopy involves the acquisition and fusion of interferometric laser light-field encodings using a lensfree, on-chip setup with laser pulsations at different wavelengths to produce marker-free phase contrast images, as shown in Fig. 1.…”