Smart computational light microscopes (SCLMs) of smart computational imaging laboratory (SCILab)

Abstract

Computational microscopy, as a subfield of computational imaging, combines optical manipulation and image algorithmic reconstruction to recover multi-dimensional microscopic images or information of micro-objects. In recent years, the revolution in light-emitting diodes (LEDs), low-cost consumer image sensors, modern digital computers, and smartphones provide fertile opportunities for the rapid development of computational microscopy. Consequently, diverse forms of computational microscopy have been invented, including digital holographic microscopy (DHM), transport of intensity equation (TIE), differential phase contrast (DPC) microscopy, lens-free on-chip holography, and Fourier ptychographic microscopy (FPM). These computational microscopy techniques not only provide high-resolution, label-free, quantitative phase imaging capability but also decipher new and advanced biomedical research and industrial applications. Nevertheless, most computational microscopy techniques are still at an early stage of “proof of concept” or “proof of prototype” (based on commercially available microscope platforms). Translating those concepts to stand-alone optical instruments for practical use is an essential step for the promotion and adoption of computational microscopy by the wider bio-medicine, industry, and education community. In this paper, we present four smart computational light microscopes (SCLMs) developed by our laboratory, i.e., smart computational imaging laboratory (SCILab) of Nanjing University of Science and Technology (NJUST), China. These microscopes are empowered by advanced computational microscopy techniques, including digital holography, TIE, DPC, lensless holography, and FPM, which not only enables multi-modal contrast-enhanced observations for unstained specimens, but also can recover their three-dimensional profiles quantitatively. We introduce their basic principles, hardware configurations, reconstruction algorithms, and software design, quantify their imaging performance, and illustrate their typical applications for cell analysis, medical diagnosis, and microlens characterization.

Transport of intensity diffraction tomography with non-interferometric synthetic aperture for three-dimensional label-free microscopy

“…However, low-frequency phase components (near zero frequency) can be totally transferred if and only if the illumination angle matches the NA of the objective lens ( ). Such a matched illumination condition is essential for accurate phase recovery based on asymmetric-illumination-based non-interferometric QPI methods, such as Fourier ptychographic microscopy (FPM) 52 – 56 and differential phase contrast microscopy (DPC) 57 , 58 .…”

Super-Resolution Imaging with Patchy Microspheres

“…We can see the formation of a "photonic hook", with the light path off-centered and curved due to the asymmetry property of the incident beam caused by the Ag coating. In terms of imaging, the oblique illumination can help the lens to capture higher orders of diffraction from the sample [33] and enhance the phase contrast [34], which turned out to be very beneficial in boosting the quality and the contrast in microsphere-based super-resolution imaging. This enhancement mechanism can play an important role in developing more advanced and reliable microsphere super-resolution imaging systems.…”

Rapid Fabrication of Smooth Micro-Optical Components on Glass by Etching-Assisted Femtosecond Laser Modification

“…With the miniaturization and integration of modern optical systems, micro-optical components exhibit notable potential applications in virtual and augmented reality [1][2][3], autonomous navigation [4], medical monitoring [5,6], and laser shaping [7,8]. Among these components, microlenses and their arrays have been widely investigated and rapidly developed owing to their easy integration and broad functions [9][10][11][12][13]. A large number of technologies have been proposed to fabricate microlenses, such as photolithography [14], electron beam lithography [15], nanoimprint [16], and etching and fs-laser direct writing (FsLDW) [17,18].…”