Large area fabrication of engineered microlens array with low sag height for light-field imaging

Kim, Hyun Myung; Kim, Min Seok; Lee, Gil Ju; Yoo, Young Jin; Song, Young Min

doi:10.1364/oe.27.004435

Cited by 31 publications

(17 citation statements)

References 16 publications

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“…Consequently, there is blur in the images shown in Figure 4. However, the optimization of the micro-lens and the image quality can be improved by minimizing the spherical aberration through an MLA with low sag height [32]. Moreover, many studies have been conducted on thin cameras using MLAs with low effective resolution.…”

Section: Resultsmentioning

confidence: 99%

Miniaturized 3D Depth Sensing-Based Smartphone Light Field Camera

Kim

Lee

et al. 2020

Sensors

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The miniaturization of 3D depth camera systems to reduce cost and power consumption is essential for their application in electrical devices that are trending toward smaller sizes (such as smartphones and unmanned aerial systems) and in other applications that cannot be realized via conventional approaches. Currently, equipment exists for a wide range of depth-sensing devices, including stereo vision, structured light, and time-of-flight. This paper reports on a miniaturized 3D depth camera based on a light field camera (LFC) configured with a single aperture and a micro-lens array (MLA). The single aperture and each micro-lens of the MLA serve as multi-camera systems for 3D surface imaging. To overcome the optical alignment challenge in the miniaturized LFC system, the MLA was designed to focus by attaching it to an image sensor. Theoretical analysis of the optical parameters was performed using optical simulation based on Monte Carlo ray tracing to find the valid optical parameters for miniaturized 3D camera systems. Moreover, we demonstrated multi-viewpoint image acquisition via a miniaturized 3D camera module integrated into a smartphone.

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Section: Resultsmentioning

confidence: 99%

Miniaturized 3D Depth Sensing-Based Smartphone Light Field Camera

Kim

Lee

et al. 2020

Sensors

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“…However, owing to defects arising from manufacturing and assembly adjustment processes, the form and orientation parameters of the MLA may deviate from the design values, resulting in mismatches between the spatial and angular information recorded by the subimages. Many kinds of MLA errors that occur in the imaging system are limited to the use of different machining materials and methods [31,32,33]. According to their characteristics, MLA errors can be classified into two categories: form errors, which include pitch error, radius-of-curvature error, and decenter error; and orientation errors, which comprise distance error, translation error, and tilt error.…”

Section: Correlated Mla Error Modelmentioning

confidence: 99%

High-Accuracy Correction of a Microlens Array for Plenoptic Imaging Sensors

Yuan

Gao

et al. 2019

Sensors

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Microlens array (MLA) errors in plenoptic cameras can cause the confusion or mismatching of 4D spatio-angular information in the image space, significantly affecting the accuracy and efficiency of target reconstruction. In this paper, we present a high-accuracy correction method for light fields distorted by MLA errors. Subpixel feature points are extracted from the microlens subimages of a raw image to obtain correction matrices and perform registration of the corresponding subimages at a subpixel level. The proposed method is applied for correcting MLA errors of two different categories in light-field images, namely form errors and orientation errors. Experimental results show that the proposed method can rectify the geometric and intensity distortions of raw images accurately and improve the quality of light-field refocusing. Qualitative and quantitative comparisons between images before and after correction verify the performance of our method in terms of accuracy, stability, and adaptability.

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“…Microlens arrays (MLAs) and MLA-based artificial compound eyes (ACEs) play a key role in advanced micro-optical systems (Pan et al, 2007 ; Song et al, 2013 ; Gorzelak et al, 2014 ; Petsch et al, 2016 ; Lin et al, 2018 ). By taking advantages of small size, high integration, and striking optical capability, MLAs and ACEs are widely applied in light-field regulation (Deng et al, 2014 ; Wei et al, 2018 ; Zhou et al, 2018 ; Sohna et al, 2019 ), fiber coupling (Elsherif et al, 2019 ; Liu et al, 2019 ; Orth et al, 2019 ), lab-on-chip devices (Fei et al, 2011 ; Lv et al, 2016 ; Vespini et al, 2016 ), biochemical observation (Ma et al, 2014 ; Holzner et al, 2018 ), laser microfabrication (Bekesi et al, 2010 ; Li et al, 2020 ), solar cells (Chen Y. et al, 2013 ), sensors (Zanella et al, 2020 ), three-dimensional imaging (Li et al, 2016 ; Kim et al, 2019 ; Zhang et al, 2019 ; Joo et al, 2020 ; Qin et al, 2020 ; Zhao et al, 2020 ), and light extraction (Shin et al, 2018 ; Zhou et al, 2019a , b ). However, the normal use of the MLA is usually restricted by many limitations.…”

Section: Introductionmentioning

confidence: 99%

Mini-Review on Bioinspired Superwetting Microlens Array and Compound Eye

et al. 2020

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Microlens arrays (MLAs) and MLA-based artificial compound eyes (ACEs) are the important miniaturized optical components in modern micro-optical systems. However, their optical performance will seriously decline once they are wetted by water droplets (such as fog, dew, and rain droplets) or are polluted by contaminations in a humid environment. In this mini-review, we summarize the research works related to the fabrication of superwetting MLAs and ACEs and show how to integrate superhydrophobic and superoleophobic microstructures with an MLA. The fabrication strategy can be split into two categories. One is the hybrid pattern composed of the MLA domain and the superwetting domain. Another is the direct formation of superwetting nanostructures on the surface of the microlenses. The superhydrophobicity or superoleophobicity endows the MLAs and ACEs with liquid repellence and self-cleaning function besides excellent optical performance. We believe that the superwetting MLAs and ACEs will have significant applications in various optical systems that are often used in the humid or liquid environment.

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Large area fabrication of engineered microlens array with low sag height for light-field imaging

Cited by 31 publications

References 16 publications

Miniaturized 3D Depth Sensing-Based Smartphone Light Field Camera

Miniaturized 3D Depth Sensing-Based Smartphone Light Field Camera

High-Accuracy Correction of a Microlens Array for Plenoptic Imaging Sensors

Mini-Review on Bioinspired Superwetting Microlens Array and Compound Eye

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