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3 pages, 190 KiB

Open AccessEditorial

Editorial for the Special Issue on Optics and Photonics in Micromachines

by Cuifang Kuang and Wei Zhao

Micromachines 2023, 14(6), 1102; https://doi.org/10.3390/mi14061102 - 23 May 2023

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Abstract

Micromachines, as a platform for manipulation, assembling, detection and imaging, is a typical interdisciplinary field related to broad areas, e [...] Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

Research

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7 pages, 1847 KiB

Open AccessArticle

Electrolysis of Bacteria Based on Microfluidic Technology

by Jianqiu Zhao, Na Li, Xinyu Zhou, Zihan Yu, Mei Lan, Siyu Chen, Jiajia Miao, Yulai Li, Guiying Li and Fang Yang

Micromachines 2023, 14(1), 144; https://doi.org/10.3390/mi14010144 - 5 Jan 2023

Cited by 3 | Viewed by 1983

Abstract

Cell lysis is a key step for studying the structure and function of proteins in cells and an important intermediate step in drug screening, cancer diagnosis, and genome analysis. The current cell lysis methods still suffer from limitations, such as the need for [...] Read more.

Cell lysis is a key step for studying the structure and function of proteins in cells and an important intermediate step in drug screening, cancer diagnosis, and genome analysis. The current cell lysis methods still suffer from limitations, such as the need for large instruments, a long and time-consuming process, a large sample volume, chemical reagent contamination, and their unsuitability for the small amount of bacteria lysis required for point-of-care testing (POCT) devices. Therefore, a fast, chemical-free, portable, and non-invasive device needs to be developed. In the present study, we designed an integrated microfluidic chip to achieve E. coli lysis by applying an alternating current (AC) electric field and investigated the effects of voltage, frequency, and flow rate on the lysis. The results showed that the lysis efficiency of the bacteria was increased with a higher voltage, lower frequency, and lower flow rate. When the voltage was at 10 V_p-p, the lysis efficiency was close to 100%. The study provided a simple, rapid, reagent-free, and high-efficiency cleavage method for biology and biomedical applications involving bacteria lysis. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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17 pages, 8462 KiB

Open AccessArticle

Miniature Deformable MEMS Mirrors for Ultrafast Optical Focusing

by Afshin Kashani Ilkhechi, Matthew Martell and Roger Zemp

Micromachines 2023, 14(1), 40; https://doi.org/10.3390/mi14010040 - 24 Dec 2022

Cited by 1 | Viewed by 1756

Abstract

Here, we introduce ultrafast tunable MEMS mirrors consisting of a miniature circular mirrored membrane, which can be electrostatically actuated to change the mirror curvature at unprecedented speeds. The central deflection zone is a close approximation to a parabolic mirror. The device is fabricated [...] Read more.

Here, we introduce ultrafast tunable MEMS mirrors consisting of a miniature circular mirrored membrane, which can be electrostatically actuated to change the mirror curvature at unprecedented speeds. The central deflection zone is a close approximation to a parabolic mirror. The device is fabricated with a minimal membrane diameter, but at least double the size of a focused optical spot. The theory and simulations are used to predict maximum relative focal shifts as a function of membrane size and deflection, beam waist, and incident focal position. These devices are demonstrated to enable fast tuning of the focal wavefront of laser beams at ≈MHz tuning rates, two to three orders of magnitude faster than current optical focusing technologies. The fabricated devices have a silicon membrane with a 30–100 μm radius and a 350 nm gap spacing between the top and bottom electrodes. These devices can change the focal position of a tightly focused beam by ≈1 mm at rates up to 4.9 MHz and with response times smaller than 5 μs. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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26 pages, 8160 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Film Thickness and Glycerol Concentration Mapping of Falling Films Based on Fluorescence and Near-Infrared Technique

by Isabel Medina, Stephan Scholl and Matthias Rädle

Micromachines 2022, 13(12), 2184; https://doi.org/10.3390/mi13122184 - 9 Dec 2022

Cited by 2 | Viewed by 1997

Abstract

Falling film evaporation processes involve high fluid velocities with continuous variations in local film thickness, fluid composition, and viscosity. This contribution presents a parallel and complementary film thickness and concentration mapping distribution in falling films using a non-invasive fluorescence and near-infrared imaging technique. [...] Read more.

Falling film evaporation processes involve high fluid velocities with continuous variations in local film thickness, fluid composition, and viscosity. This contribution presents a parallel and complementary film thickness and concentration mapping distribution in falling films using a non-invasive fluorescence and near-infrared imaging technique. The experiments were performed with a mixture of glycerol/water with a mass fraction from 0 to 0.65

g_{g l y c} g_{t o t a l}^{- 1}

and operating ranges similar to evaporation processes. The measurement system was designed by integrating two optical measurement methods for experimental image analysis. The film thickness was evaluated using a VIS camera and high-power LEDs at 470 nm. The local glycerol concentration

g_{g l y c} g_{t o t a l}^{- 1}

was determined using a NIR camera and high-power LEDs at 1050, 1300, 1450 and 1550 nm. A multiwavelength analysis with all NIR wavelengths was implemented with a better correlation for falling films at low flow velocity. The results show an improvement in the analysis of falling films with high flow velocities up to almost 500 mm/s by using only the 1450 nm wavelength and the fluorescence measurement. Simultaneous imaging analysis of film thickness and concentration in falling films provides further insight into understanding mass and heat transport and thus supports the optimization of falling film evaporators. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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11 pages, 3474 KiB

Open AccessArticle

Vertical Cavity Surface Emitting Laser Performance Maturing through Machine Learning for High-Yield Optical Wireless Network

by Ammar Armghan, Khaled Aliqab, Farman Ali, Fayadh Alenezi and Meshari Alsharari

Micromachines 2022, 13(12), 2132; https://doi.org/10.3390/mi13122132 - 1 Dec 2022

Cited by 2 | Viewed by 1617

Abstract

The high-yield optical wireless network (OWN) is a promising framework to strengthen 5G and 6G mobility. In addition, high direction and narrow bandwidth-based laser beams are enormously noteworthy for high data transmission over standard optical fibers. Therefore, in this paper, the performance of [...] Read more.

The high-yield optical wireless network (OWN) is a promising framework to strengthen 5G and 6G mobility. In addition, high direction and narrow bandwidth-based laser beams are enormously noteworthy for high data transmission over standard optical fibers. Therefore, in this paper, the performance of a vertical cavity surface emitting laser (VCSEL) is evaluated using the machine learning (ML) technique, aiming to purify the optical beam and enable OWN to support high-speed, multi-user data transmission. The ML technique is applied on a designed VCSEL array to optimize paths for DC injection, AC signal modulation, and multiple-user transmission. The mathematical model of VCSEL narrow beam, OWN, and energy loss through nonlinear interference in an optical wireless network is studied. In addition, the mathematical model is then affirmed with a simulation model following the bit error rate (BER), the laser power, the current, and the fiber-length performance matrices. The results estimations declare that the presented methodology offers a narrow beam of VCSEL, mitigating nonlinear interference in OWN and increasing energy efficiency. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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14 pages, 5094 KiB

Open AccessArticle

Design of Monolithic 2D Optical Phased Arrays Heterogeneously Integrated with On-Chip Laser Arrays Based on SOI Photonic Platform

by Jian Yue, Anqi Cui, Fei Wang, Lei Han, Jinguo Dai, Xiangyi Sun, Hang Lin, Chunxue Wang, Changming Chen and Daming Zhang

Micromachines 2022, 13(12), 2117; https://doi.org/10.3390/mi13122117 - 30 Nov 2022

Cited by 2 | Viewed by 1726

Abstract

In this work, heterogeneous integration of both two-dimensional (2D) optical phased arrays (OPAs) and on-chip laser arrays based on a silicon photonic platform is proposed. The tunable multi-quantum-well (MQW) laser arrays, active switching/shifting arrays, and grating antenna arrays are used in the OPA [...] Read more.

In this work, heterogeneous integration of both two-dimensional (2D) optical phased arrays (OPAs) and on-chip laser arrays based on a silicon photonic platform is proposed. The tunable multi-quantum-well (MQW) laser arrays, active switching/shifting arrays, and grating antenna arrays are used in the OPA module to realize 2D spatial beam scanning. The 2D OPA chip is composed of four main parts: (1) tunable MQW laser array emitting light signals in the range of 1480–1600 nm wavelengths; (2) electro-optic (EO) switch array for selecting the desired signal light from the on-chip laser array; (3) EO phase-shifter array for holding a fixed phase difference for the uniform amplitude of specific optical signal; and (4) Bragg waveguide grating antenna array for controlling beamforming. By optimizing the overall performances of the 2D OPA chip, a large steering range of 88.4° × 18° is realized by tuning both the phase and the wavelength for each antenna. In contrast to the traditional thermo-optic LIDAR chip with an external light source, the overall footprint of the 2D OPA chip can be limited to 8 mm × 3 mm, and the modulation rate can be 2.5 ps. The ultra-compact 2D OPA assembling with on-chip tunable laser arrays using hybrid integration could result in the application of a high-density, high-speed, and high-precision lidar system in the future. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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10 pages, 2230 KiB

Open AccessArticle

Influencing Effects of Fabrication Errors on Performances of the Dielectric Metalens

by Guoqing Xu, Qianlong Kang, Xueqiang Fan, Guanghui Yang, Kai Guo and Zhongyi Guo

Micromachines 2022, 13(12), 2098; https://doi.org/10.3390/mi13122098 - 28 Nov 2022

Cited by 4 | Viewed by 1258

Abstract

Despite continuous developments of manufacturing technology for micro-devices and nano-devices, fabrication errors still exist during the manufacturing process. To reduce manufacturing costs and save time, it is necessary to analyze the effects of fabrication errors on the performances of micro-/nano-devices, such as the [...] Read more.

Despite continuous developments of manufacturing technology for micro-devices and nano-devices, fabrication errors still exist during the manufacturing process. To reduce manufacturing costs and save time, it is necessary to analyze the effects of fabrication errors on the performances of micro-/nano-devices, such as the dielectric metasurface-based metalens. Here, we mainly analyzed the influences of fabrication errors in dielectric metasurface-based metalens, including geometric size and shape of the unit element, on the focusing efficiency and the full width at half maximum (FWHM) values. Simulation results demonstrated that the performance of the metasurface was robust to fabrication errors within a certain range, which provides a theoretical guide for the concrete fabrication processes of dielectric metasurfaces. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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11 pages, 7215 KiB

Open AccessArticle

Fabrication of Chiral 3D Microstructure Using Tightly Focused Multiramp Helico-Conical Optical Beams

by Jisen Wen, Qiuyuan Sun, Mengdi Luo, Chengpeng Ma, Zhenyao Yang, Chenyi Su, Chun Cao, Dazhao Zhu, Chenliang Ding, Liang Xu, Cuifang Kuang and Xu Liu

Micromachines 2022, 13(10), 1771; https://doi.org/10.3390/mi13101771 - 18 Oct 2022

Cited by 14 | Viewed by 2201

Abstract

Beams with optical vortices are widely used in various fields, including optical communication, optical manipulation and trapping, and, especially in recent years, in the processing of nanoscale structures. However, circular vortex beams are difficult to use for the processing of chiral micro and [...] Read more.

Beams with optical vortices are widely used in various fields, including optical communication, optical manipulation and trapping, and, especially in recent years, in the processing of nanoscale structures. However, circular vortex beams are difficult to use for the processing of chiral micro and nanostructures. This paper introduces a multiramp helical–conical beam that can produce a three-dimensional spiral light field in a tightly focused system. Using this spiral light beam and the two-photon direct writing technique, micro–nano structures with chiral characteristics in space can be directly written under a single exposure. The fabrication efficiency is more than 20 times higher than the conventional point-by-point writing strategy. The tightly focused properties of the light field were utilized to analyze the field-dependent properties of the micro–nano structure, such as the number of multiramp mixed screw-edge dislocations. Our results enrich the means of two-photon polymerization technology and provide a simple and stable way for the micromachining of chiral microstructures, which may have a wide range of applications in optical tweezers, optical communications, and metasurfaces. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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11 pages, 3370 KiB

Open AccessArticle

Generation and Modulation of Controllable Multi-Focus Array Based on Phase Segmentation

by Zihan Liu, Jiaqing Hou, Yu Zhang, Tong Wen, Lianbin Fan, Chen Zhang, Kaige Wang and Jintao Bai

Micromachines 2022, 13(10), 1677; https://doi.org/10.3390/mi13101677 - 5 Oct 2022

Cited by 2 | Viewed by 1699

Abstract

A Circular-Sectorial Phase Segmentation (CSPS) noniterative method for effectively generating and manipulating muti-focus array (MFA) was proposed in this work. The theoretical model of the CSPS was built up based on vectorial diffraction integral and the phase modulation factor was deduced with inverse [...] Read more.

A Circular-Sectorial Phase Segmentation (CSPS) noniterative method for effectively generating and manipulating muti-focus array (MFA) was proposed in this work. The theoretical model of the CSPS was built up based on vectorial diffraction integral and the phase modulation factor was deduced with inverse fast Fourier transform. By segmenting the entrance pupil into specified regions, which were sequentially assigned with the values carried out by phase modulation factor, the methodology could generate flexible MFAs with desired position and morphology. Subsequently, the CSPS was investigated in parallelized fabrication with a laser direct writing system. The positioning accuracy was greater than 96% and the morphologic consistency of the parallelly fabricated results was greater than 92%. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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9 pages, 2367 KiB

Open AccessArticle

Low-Cost In Vivo Full-Range Optical Coherence Tomography Using a Voice Coil Motor

by Xiaoqiao Liao, Liang He, Zhao Duan, Peng Tian, Yu He, Qinyuan Deng, Zeyu Ma, Ruiqi Song and Leixin Wu

Micromachines 2022, 13(10), 1626; https://doi.org/10.3390/mi13101626 - 28 Sep 2022

Cited by 1 | Viewed by 1551

Abstract

In this work, we demonstrated a novel and low-cost full-range optical coherence tomography (FROCT) method. In comparison with the off-pivot approach, which needs precise control of the deflecting distance and should be adjusted for different situations, our proposed method is more flexible without [...] Read more.

In this work, we demonstrated a novel and low-cost full-range optical coherence tomography (FROCT) method. In comparison with the off-pivot approach, which needs precise control of the deflecting distance and should be adjusted for different situations, our proposed method is more flexible without regulating the system itself. Different from the previous systems reported in the literature, which used a high-cost piezo-driven stage to introduce the phase modulation, our system utilizes a cost-effective voice coil motor for retrieving the complex-valued spectral signal. The complex-valued data, with a twofold increase in the accessible depth range, can be calculated using an algorithm based on the Hilbert transform and Dirac delta function. To confirm the effectivity of our method, both simulation and experiments were performed. In particular, for the in vivo experiment, we presented the FROCT result of a fingernail fold, demonstrating the availability of in vivo imaging. Since the key element of our system is a low-cost voice coil motor, which is flexible and more accessible for most of the clinics, we believe that it has great potential to be a clinical modality in the future. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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13 pages, 5904 KiB

Open AccessArticle

Super-Resolution Reconstruction of Cytoskeleton Image Based on A-Net Deep Learning Network

by Qian Chen, Haoxin Bai, Bingchen Che, Tianyun Zhao, Ce Zhang, Kaige Wang, Jintao Bai and Wei Zhao

Micromachines 2022, 13(9), 1515; https://doi.org/10.3390/mi13091515 - 13 Sep 2022

Cited by 2 | Viewed by 1698

Abstract

To date, live-cell imaging at the nanometer scale remains challenging. Even though super-resolution microscopy methods have enabled visualization of sub-cellular structures below the optical resolution limit, the spatial resolution is still far from enough for the structural reconstruction of biomolecules in vivo (i.e., [...] Read more.

To date, live-cell imaging at the nanometer scale remains challenging. Even though super-resolution microscopy methods have enabled visualization of sub-cellular structures below the optical resolution limit, the spatial resolution is still far from enough for the structural reconstruction of biomolecules in vivo (i.e., ~24 nm thickness of microtubule fiber). In this study, a deep learning network named A-net was developed and shows that the resolution of cytoskeleton images captured by a confocal microscope can be significantly improved by combining the A-net deep learning network with the DWDC algorithm based on a degradation model. Utilizing the DWDC algorithm to construct new datasets and taking advantage of A-net neural network’s features (i.e., considerably fewer layers and relatively small dataset), the noise and flocculent structures which originally interfere with the cellular structure in the raw image are significantly removed, with the spatial resolution improved by a factor of 10. The investigation shows a universal approach for exacting structural details of biomolecules, cells and organs from low-resolution images. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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10 pages, 5358 KiB

Open AccessArticle

Two-Step Converging Spherical Wave Diffracted at a Circular Aperture of Digital In-Line Holography

by Peng Tian, Liang He, Xiaoyi Guo, Zeyu Ma, Ruiqi Song, Xiaoqiao Liao and Fangji Gan

Micromachines 2022, 13(8), 1284; https://doi.org/10.3390/mi13081284 - 9 Aug 2022

Cited by 1 | Viewed by 1221

Abstract

The aspheric light emitted from a pinhole restrains the reconstruction quality of a digital in-line hologram. Herein, the Fresnel-diffracted spot from the first step converging spherical wave diffracted at a rough circular aperture is collimated and expanded to generate an even plane wave, [...] Read more.

The aspheric light emitted from a pinhole restrains the reconstruction quality of a digital in-line hologram. Herein, the Fresnel-diffracted spot from the first step converging spherical wave diffracted at a rough circular aperture is collimated and expanded to generate an even plane wave, which is converged again by an objective lens and matching a minimum aperture while the central spot is varying from light to dark. We observed that the collected background hologram is filled with a round spot with high contrast as an ideal spherical wave. The resolution board and biology experimental results demonstrated a distinctively reconstructed image without any image processing in a single exposure. The adjustable field of view and magnification, single exposure, and noncontact make it suitable for an online microscope. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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12 pages, 2483 KiB

Open AccessArticle

Performance Improvement of Single-Frequency CW Laser Using a Temperature Controller Based on Machine Learning

by Haoming Qiao, Weina Peng, Pixian Jin, Jing Su and Huadong Lu

Micromachines 2022, 13(7), 1047; https://doi.org/10.3390/mi13071047 - 30 Jun 2022

Cited by 3 | Viewed by 1840

Abstract

The performance improvement of an all-solid-state single-frequency continuous-wave (CW) laser with high output power is presented in this paper, which is implemented by employing a temperature control system based on machine learning to control the temperature of laser elements including gain crystal, laser [...] Read more.

The performance improvement of an all-solid-state single-frequency continuous-wave (CW) laser with high output power is presented in this paper, which is implemented by employing a temperature control system based on machine learning to control the temperature of laser elements including gain crystal, laser diode and so on. Because the developed temperature controller based on machine learning combines the back propagation (BP) neural network algorithm with the proportion-integration-differentiation (PID) control algorithm, the parameters of the PID are adaptive with the variation of the environment. As a result, the control speeds and control abilities of the temperatures of the elements are dramatically enhanced. In this case, the output characteristic and the adaptability to the environment as well as the stability of the single-frequency CW laser are also improved greatly. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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15 pages, 3985 KiB

Open AccessArticle

The Mechanism of Dynamic Interaction between Doxorubicin and Calf Thymus DNA at the Single-Molecule Level Based on Confocal Raman Spectroscopy

by Ruihong Zhang, Jie Zhu, Dan Sun, Jie Li, Lina Yao, Shuangshuang Meng, Yan Li, Yang Dang and Kaige Wang

Micromachines 2022, 13(6), 940; https://doi.org/10.3390/mi13060940 - 13 Jun 2022

Cited by 11 | Viewed by 2277

Abstract

It is of great fundamental significance and practical application to understand the binding sites and dynamic process of the interaction between doxorubicin (DOX) and DNA molecules. Based on the Confocal Raman spectroscopy, the interaction between DOX and calf thymus DNA has been systemically [...] Read more.

It is of great fundamental significance and practical application to understand the binding sites and dynamic process of the interaction between doxorubicin (DOX) and DNA molecules. Based on the Confocal Raman spectroscopy, the interaction between DOX and calf thymus DNA has been systemically investigated, and some meaningful findings have been found. DOX molecules can not only interact with all four bases of DNA molecules, i.e., adenine, thymine, cytosine, guanine, and phosphate, but also affect the DNA conformation. Meanwhile, the binding site of DOX and its derivatives such as daunorubicin and epirubicin is certain. Furthermore, the interaction between DOX and DNA molecules is a dynamic process since the intensities of each characteristic peaks of the base, e.g., adenine, cytosine, and phosphate, are all regularly changed with the interaction time. Finally, a dynamic mechanism model of the interaction between DOX and DNA molecules is proposed; that is, there are two kinds of interaction between DOX and DNA molecules: DOX-DNA acts to form a complex, and DOX-DOX acts to form a multimer. The two effects are competitive, as the former compresses DNA molecules, and the latter decompresses these DNA molecules. This work is helpful for accurately understanding and developing new drugs and pathways to improve and treat DOX-induced cytotoxicity and cardiotoxicity. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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15 pages, 7708 KiB

Open AccessArticle

Feature Extraction of 3T3 Fibroblast Microtubule Based on Discrete Wavelet Transform and Lucy–Richardson Deconvolution Methods

by Haoxin Bai, Bingchen Che, Tianyun Zhao, Wei Zhao, Kaige Wang, Ce Zhang and Jintao Bai

Micromachines 2022, 13(6), 824; https://doi.org/10.3390/mi13060824 - 25 May 2022

Cited by 1 | Viewed by 1541

Abstract

Accompanied by the increasing requirements of the probing micro/nanoscopic structures of biological samples, various image-processing algorithms have been developed for visualization or to facilitate data analysis. However, it remains challenging to enhance both the signal-to-noise ratio and image resolution using a single algorithm. [...] Read more.

Accompanied by the increasing requirements of the probing micro/nanoscopic structures of biological samples, various image-processing algorithms have been developed for visualization or to facilitate data analysis. However, it remains challenging to enhance both the signal-to-noise ratio and image resolution using a single algorithm. In this investigation, we propose a composite image processing method by combining discrete wavelet transform (DWT) and the Lucy–Richardson (LR) deconvolution method, termed the DWDC method. Our results demonstrate that the signal-to-noise ratio and resolution of live cells’ microtubule networks are considerably improved, allowing the recognition of features as small as 120 nm. The method shows robustness in processing the high-noise images of filament-like biological structures, e.g., the cytoskeleton networks captured by fluorescent microscopes. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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18 pages, 80059 KiB

Open AccessArticle

All-In-Focus Polarimetric Imaging Based on an Integrated Plenoptic Camera with a Key Electrically Tunable LC Device

by Mingce Chen, Zhexun Li, Mao Ye, Taige Liu, Chai Hu, Jiashuo Shi, Kewei Liu, Zhe Wang and Xinyu Zhang

Micromachines 2022, 13(2), 192; https://doi.org/10.3390/mi13020192 - 26 Jan 2022

Cited by 3 | Viewed by 1870

Abstract

In this paper, a prototyped plenoptic camera based on a key electrically tunable liquid-crystal (LC) device for all-in-focus polarimetric imaging is proposed. By using computer numerical control machining and 3D printing, the proposed imaging architecture can be integrated into a hand-held prototyped plenoptic [...] Read more.

In this paper, a prototyped plenoptic camera based on a key electrically tunable liquid-crystal (LC) device for all-in-focus polarimetric imaging is proposed. By using computer numerical control machining and 3D printing, the proposed imaging architecture can be integrated into a hand-held prototyped plenoptic camera so as to greatly improve the applicability for outdoor imaging measurements. Compared with previous square-period liquid-crystal microlens arrays (LCMLA), the utilized hexagonal-period LCMLA has remarkably increased the light utilization rate by ~15%. Experiments demonstrate that the proposed imaging approach can simultaneously realize both the plenoptic and polarimetric imaging without any macroscopic moving parts. With the depth-based rendering method, both the all-in-focus images and the all-in-focus degree of linear polarization (DoLP) images can be obtained efficiently. Due to the large depth-of-field advantage of plenoptic cameras, the proposed camera enables polarimetric imaging in a larger depth range than conventional 2D polarimetric cameras. Currently, the raw light field images with three polarization states including I₀ and I₆₀ and I₁₂₀ can be captured by the proposed imaging architecture, with a switching time of several tens of milliseconds. Some local patterns which are selected as interested target features can be effectively suppressed or obviously enhanced by switching the polarization state mentioned. According to experiments, the visibility in scattering medium can also be apparently improved. It can be expected that the proposed polarimetric imaging approach will exhibit an excellent development potential. Full article

(This article belongs to the Special Issue Optics and Photonics in Micromachines)

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