scholarly journals High-Identical Numerical Aperture, Multifocal Microlens Array through Single-Step Multi-Sized Hole Patterning Photolithography

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1068
Author(s):  
Joong Hoon Lee ◽  
Sehui Chang ◽  
Min Seok Kim ◽  
Yeong Jae Kim ◽  
Hyun Myung Kim ◽  
...  
Keyword(s):  
Numerical Aperture ◽  
Microlens Array ◽  
Depth Estimation ◽  
Single Step ◽  
Depth Of Field ◽  
Wide Field ◽  
Depth Sensor ◽  
Plane Image ◽  
Wet Etch ◽  
Photolithography Process

Imaging applications based on microlens arrays (MLAs) have a great potential for the depth sensor, wide field-of-view camera and the reconstructed hologram. However, the narrow depth-of-field remains the challenge for accurate, reliable depth estimation. Multifocal microlens array (Mf-MLAs) is perceived as a major breakthrough, but existing fabrication methods are still hindered by the expensive, low-throughput, and dissimilar numerical aperture (NA) of individual lenses due to the multiple steps in the photolithography process. This paper reports the fabrication method of high NA, Mf-MLAs for the extended depth-of-field using single-step photolithography assisted by chemical wet etching. The various lens parameters of Mf-MLAs are manipulated by the multi-sized hole photomask and the wet etch time. Theoretical and experimental results show that the Mf-MLAs have three types of lens with different focal lengths, while maintaining the uniform and high NA irrespective of the lens type. Additionally, we demonstrate the multi-focal plane image acquisition via Mf-MLAs integrated into a microscope.

scholarly journals Optical Projection Tomography Using a Commercial Microfluidic System

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 293
Author(s):  
Wenhao Du ◽  
Cheng Fei ◽  
Junliang Liu ◽  
Yongfu Li ◽  
Zhaojun Liu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Numerical Aperture ◽  
Microfluidic System ◽  
Depth Of Field ◽  
Objective Lens ◽  
Flow Mode ◽  
Wide Field ◽  
Optical Projection Tomography ◽  
Microfluidic Systems ◽  
Optical Projection

Optical projection tomography (OPT) is the direct optical equivalent of X-ray computed tomography (CT). To obtain a larger depth of field, traditional OPT usually decreases the numerical aperture (NA) of the objective lens to decrease the resolution of the image. So, there is a trade-off between sample size and resolution. Commercial microfluidic systems can observe a sample in flow mode. In this paper, an OPT instrument is constructed to observe samples. The OPT instrument is combined with commercial microfluidic systems to obtain a three-dimensional and time (3D + T)/four-dimensional (4D) video of the sample. “Focal plane scanning” is also used to increase the images’ depth of field. A series of two-dimensional (2D) images in different focal planes was observed and compared with images simulated using our program. Our work dynamically monitors 3D OPT images. Commercial microfluidic systems simulate blood flow, which has potential application in blood monitoring and intelligent drug delivery platforms. We design an OPT adaptor to perform OPT on a commercial wide-field inverted microscope (Olympusix81). Images in different focal planes are observed and analyzed. Using a commercial microfluidic system, a video is also acquired to record motion pictures of samples at different flow rates. To our knowledge, this is the first time an OPT setup has been combined with a microfluidic system.

scholarly journals Single-shot 3D wide-field fluorescence imaging with a Computational Miniature Mesoscope

2020 ◽  
Vol 6 (43) ◽  
pp. eabb7508
Author(s):  
Yujia Xue ◽  
Ian G. Davison ◽  
David A. Boas ◽  
Lei Tian
Keyword(s):  
Light Emitting Diode ◽  
Lightweight Design ◽  
Three Dimensional ◽  
Microlens Array ◽  
Computational Imaging ◽  
Depth Of Field ◽  
Wide Field ◽  
Single Shot ◽  
Light Emitting ◽  
Imaging Capability

Fluorescence microscopes are indispensable to biology and neuroscience. The need for recording in freely behaving animals has further driven the development in miniaturized microscopes (miniscopes). However, conventional microscopes/miniscopes are inherently constrained by their limited space-bandwidth product, shallow depth of field (DOF), and inability to resolve three-dimensional (3D) distributed emitters. Here, we present a Computational Miniature Mesoscope (CM2) that overcomes these bottlenecks and enables single-shot 3D imaging across an 8 mm by 7 mm field of view and 2.5-mm DOF, achieving 7-μm lateral resolution and better than 200-μm axial resolution. The CM2 features a compact lightweight design that integrates a microlens array for imaging and a light-emitting diode array for excitation. Its expanded imaging capability is enabled by computational imaging that augments the optics by algorithms. We experimentally validate the mesoscopic imaging capability on 3D fluorescent samples. We further quantify the effects of scattering and background fluorescence on phantom experiments.

scholarly journals Recurrent neural network-based volumetric fluorescence microscopy

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Luzhe Huang ◽  
Hanlong Chen ◽  
Yilin Luo ◽  
Yair Rivenson ◽  
Aydogan Ozcan
Keyword(s):  
Neural Network ◽  
Image Reconstruction ◽  
Fluorescence Microscopy ◽  
Recurrent Network ◽  
Sample Volume ◽  
Depth Of Field ◽  
Objective Lens ◽  
Wide Field ◽  
Volumetric Imaging ◽  
3D Image Reconstruction

AbstractVolumetric imaging of samples using fluorescence microscopy plays an important role in various fields including physical, medical and life sciences. Here we report a deep learning-based volumetric image inference framework that uses 2D images that are sparsely captured by a standard wide-field fluorescence microscope at arbitrary axial positions within the sample volume. Through a recurrent convolutional neural network, which we term as Recurrent-MZ, 2D fluorescence information from a few axial planes within the sample is explicitly incorporated to digitally reconstruct the sample volume over an extended depth-of-field. Using experiments on C. elegans and nanobead samples, Recurrent-MZ is demonstrated to significantly increase the depth-of-field of a 63×/1.4NA objective lens, also providing a 30-fold reduction in the number of axial scans required to image the same sample volume. We further illustrated the generalization of this recurrent network for 3D imaging by showing its resilience to varying imaging conditions, including e.g., different sequences of input images, covering various axial permutations and unknown axial positioning errors. We also demonstrated wide-field to confocal cross-modality image transformations using Recurrent-MZ framework and performed 3D image reconstruction of a sample using a few wide-field 2D fluorescence images as input, matching confocal microscopy images of the same sample volume. Recurrent-MZ demonstrates the first application of recurrent neural networks in microscopic image reconstruction and provides a flexible and rapid volumetric imaging framework, overcoming the limitations of current 3D scanning microscopy tools.

scholarly journals Ultrawide-angle and high-efficiency metalens in hexagonal arrangement

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chun-Yuan Fan ◽  
Chia-Ping Lin ◽  
Guo-Dung J. Su
Keyword(s):  
High Efficiency ◽  
Numerical Aperture ◽  
Vital Role ◽  
Optical Systems ◽  
Wide Field ◽  
Wide Angle ◽  
Camera Systems ◽  
Single Lens ◽  
Hexagonal Arrangement ◽  
Virtual And Augmented Reality

Abstract Wide-angle optical systems play a vital role in imaging applications and have been researched for many years. In traditional lenses, attaining a wide field of view (FOV) by using a single optical component is difficult because these lenses have crucial aberrations. In this study, we developed a wide-angle metalens with a numerical aperture of 0.25 that provided a diffraction-limited FOV of over 170° for a wavelength of 532 nm without the need for image stitching or multiple lenses. The designed wide-angle metalens is free of aberration and polarization, and its full width of half maximum is close to the diffraction limit at all angles. Moreover, the metalens which is designed through a hexagonal arrangement exhibits higher focusing efficiency at all angles than most-seen square arrangement. The focusing efficiencies are as high as 82% at a normal incident and 45% at an incident of 85°. Compared with traditional optical components, the proposed metalens exhibits higher FOV and provides a more satisfactory image quality because of aberration correction. Because of the advantages of the proposed metalens, which are difficult to achieve for a traditional single lens, it has the potential to be applied in camera systems and virtual and augmented reality.

Fabrication of bioinspired omnidirectional and gapless microlens array for wide field-of-view detections

2012 ◽  
Vol 100 (13) ◽  
pp. 133701 ◽  
Author(s):  
Hewei Liu ◽  
Feng Chen ◽  
Qing Yang ◽  
Pubo Qu ◽  
Shengguan He ◽  
...  
Keyword(s):  
Microlens Array ◽  
Field Of View ◽  
Wide Field ◽  
Wide Field Of View

scholarly journals Visually Guided Microassembly with Active Zooming

2006 ◽  
Vol 18 (6) ◽  
pp. 787-794
Author(s):  
Xiaodong Tao ◽  
◽  
Hyungsuck Cho ◽  
Youngjun Cho ◽  
Keyword(s):  
High Resolution ◽  
Field Of View ◽  
Depth Of Field ◽  
Wide Field ◽  
Small Field ◽  
Depth Of Focus ◽  
Large Depth ◽  
Small Depth ◽  
Wide Field Of View ◽  
Small Field Of View

Vision techniques used in automatic microassembly are limited by inherent problems such as small depth of focus and small field of view. Microassembly must, however, initially detect microparts in a wide field of view and large depth of field while maintaining high resolution. We propose microassembly using active zooming that can overcome these limitations. For a small field of view, active zooming prevents the target from getting out of the field of view during microassembly. For a small depth of focus, our proposal is based on focus measure to maintain clear target image in the field of view during microassembly. Two-step assembly thus ensures zoom microscopy maintaining a wide field of view and large depth of field initially and high resolution at the end. Peg-in-hole assembly experiments confirmed the feasibility of our proposal.

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