Large-Area, High-Resolution Birefringence Imaging with Polarization-Sensitive Fourier Ptychographic Microscopy

Abstract

We present polarization-sensitive Fourier ptychographic microscopy (PS-FPM) capable of generating high-resolution birefringence images of optically anisotropic specimens over a large field of view (FoV). FPM produces high-resolution images of transparent samples over a large FoV based on multiple intensity measurements acquired at various illumination angles and ptychographic phase retrieval. We combine this attractive feature of FPM with a single-input-state illumination and polarizationdiverse imaging system to achieve the imaging of both complex and birefringence information on transparent objects. Compared to conventional polarization imaging techniques, PS-FPM does not involve any mechanical rotation of the polarizer/analyzer and achieves birefringence imaging with a half-pitch resolution of 0.55 μm over 3.78 mm 2 FoV, which corresponds to the spacebandwidth product of 12.5 megapixels. We demonstrate the high-resolution, large-area birefringence imaging capability of PS-FPM by presenting the birefringence images of various anisotropic objects including monosodium urate, Tilia stem, and hemozoin crystals.

Tensorial tomographic differential phase-contrast microscopy

“…Zoom-ins of select regions are also presented in (d). These results suggest that the reconstructed orientations of line-shape MSU samples follow the structural directions of the sample, in agreement with prior works [17,19,20]. Figure 2(c) shows a 3D view of the reconstructed birefringence for the field-of-view (FOV) labelled in (b).…”

“…First, to relieve the ill-poseness of the problem, we have approximated the permittivity tensor with its lateral components. Although widely used [18,19,20,24], this simplification disregards out-of-plane anisotropy, which can contain valuable biological and diagnostic information [25,46]. Using more angular and polarizationdiverse patterns can potentially allow reconstruction of uni-axial, or even more general permittivity tensors, from which out-of-plane orientations can be derived.…”

“…The spatially resolved orientation is computed using Eq.23. To best visualize orientation results, we follow the convention [17,19,20] to display the multidimensional polarization data using an HSV colormap, where value displays birefringence, orientation is coded in hue, and saturation is set to one. Zoom-ins of select regions are also presented in (d).…”

“…While those methods can image quantitative Jones matrix at high-speed, holographic systems still remain challenging to align, and coherent speckle artifacts maybe present to decline image quality. angular diversity in the illumination to enable high spatial-bandwidth product images [19,20], but also polarization diversity to further incorporate the depolarization effects [7], for instance.…”

Flexible and High-Throughput Photothermal Biosensors for Rapid Screening of Acute Myocardial Infarction Using Thermochromic Paper-Based Image Analysis

“…It should be acknowledged that thermochromic materials have made an everlasting contribution to information cryptography and monitoring of human body temperature in the COVID-19 general environment. Notably, Joo et al worked on the development of efficient paper-based lateral flow analysis (LFA) systems, including optical, thermographic and electrochemical systems, leading to the maturation of LFA systems for commercialization. , More importantly, an Au NP-based biosensing system for photothermal agent light scattering imaging has been developed and proven to be highly efficient and sensitive, which is considered a clear trend to develop a biosensing element that is simple to operate and inexpensive to produce. , To this end, our objective for this work is to build a photothermal–thermochromic sensing platform for the monitoring of cTnI protein by combining target-induced photothermal effects with low-cost thermochromic materials. In this approach, the sensing platform does not require the assistance of any electronic systems.…”