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Holographic microscopy

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https://www.readbyqxmd.com/read/29221080/integrated-pillar-scatterers-for-speeding-up-classification-of-cell-holograms
#1
Alessio Lugnan, Joni Dambre, Peter Bienstman
The computational power required to classify cell holograms is a major limit to the throughput of label-free cell sorting based on digital holographic microscopy. In this work, a simple integrated photonic stage comprising a collection of silica pillar scatterers is proposed as an effective nonlinear mixing interface between the light scattered by a cell and an image sensor. The light processing provided by the photonic stage allows for the use of a simple linear classifier implemented in the electric domain and applied on a limited number of pixels...
November 27, 2017: Optics Express
https://www.readbyqxmd.com/read/29216604/digital-holographic-microscopy-for-3d-surface-characterization-of-polymeric-nanocomposites
#2
Vahid Abbasian, Ehsan A Akhlaghi, Mohammad A Charsooghi, Maasoomeh Bazzar, Ali-Reza Moradi
The aim of this paper is to introduce digital holographic microscopy (DHM) as a non-contact, inexpensive, and non-abrasive method for 3D surface characterization of polymeric nanocomposites. A common-path and vibration-immune Mirau system with a microsphere-assisted arrangement is utilized to increase the lateral resolution of the images. The characterization is performed through the measurement of roughness parameters of the surfaces, which are derived from the recorded holograms. Pure poly(triazole-amide-imide) (PTAI) and PTAI nanocomposite reinforeced with surface modified TiO2 nanoparticles (MN-TiO2) are used and compared...
November 28, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/29216124/phase-shifting-digital-holographic-microscopy-by-using-a-multi-camera-setup
#3
Carlos Trujillo, Jorge Garcia-Sucerquia
In this Letter, the use of two-coupled Mach-Zehnder interferometers for four π/2-phase shifting interferometry is introduced. A multi-camera arrangement using no more than beam splitters and mirrors is utilized to obtain in a single shot the needed phase-shifted interferograms in the different output channels of the setup. The simplicity of the setup makes it ideal for high-speed interferometry applications. This proposal is validated in digital holographic microscopy to visualize a biological sample of epidermal onion cells...
December 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/29205817/electron-holographic-study-of-semiconductor-light-emitting-diodes
#4
REVIEW
Luying Li, Xiaokang Hu, Yihua Gao
Semiconductor light-emitting diodes (LEDs), especially GaN-based heterostructures, are widely used in light illumination. The lack of inversion symmetry of wurtzite crystal structures and the lattice mismatch at heterointerfaces cause large polarization fields with contributions from both spontaneous polarization and piezoelectric polarization, which in turn results in obvious quantum confined stark effect. It is possible to alleviate this effect if the local electrostatic fields and band alignment induced charge redistribution can be quantitatively determined across the heterostructures...
December 4, 2017: Small
https://www.readbyqxmd.com/read/29168877/full-angle-tomographic-phase-microscopy-of-flowing-quasi-spherical-cells
#5
Massimiliano M Villone, Pasquale Memmolo, Francesco Merola, Martina Mugnano, Lisa Miccio, Pier Luca Maffettone, Pietro Ferraro
We report a reliable full-angle tomographic phase microscopy (FA-TPM) method for flowing quasi-spherical cells along microfluidic channels. This method lies in a completely passive optical system, i.e. mechanical scanning or multi-direction probing of the sample is avoided. It exploits the engineered rolling of cells while they are flowing along a microfluidic channel. Here we demonstrate significant progress with respect to the state of the art of in-flow TPM by showing a general extension to cells having almost spherical shapes while they are flowing in suspension...
November 23, 2017: Lab on a Chip
https://www.readbyqxmd.com/read/29162547/compact-in-line-lensfree-digital-holographic-microscope
#6
Manon Rostykus, Ferréol Soulez, Michael Unser, Christophe Moser
Phase imaging brings information about transparent samples such as biological ones. Digital holographic microscopy is a well-known method to visualize transparent samples via the phase information without any staining. Lensfree digital holographic microscopes (DHM) offer the added advantage to provide large field of views (several mm(2) and compared to several hundred μm(2)) and more compact setups that traditional DHM. In this article, a lensfree DHM is presented using a side illumination technique in order to further reduce the device size...
November 18, 2017: Methods: a Companion to Methods in Enzymology
https://www.readbyqxmd.com/read/29155763/quantifying-microorganisms-at-low-concentrations-using-digital-holographic-microscopy-dhm
#7
Manuel Bedrossian, Casey Barr, Chris A Lindensmith, Kenneth Nealson, Jay L Nadeau
Accurately detecting and counting sparse bacterial samples has many applications in the food, beverage, and pharmaceutical processing industries, in medical diagnostics, and for life detection by robotic missions to other planets and moons of the solar system. Currently, sparse bacterial samples are counted by culture plating or epifluorescence microscopy. Culture plates require long incubation times (days to weeks), and epifluorescence microscopy requires extensive staining and concentration of the sample...
November 1, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29131185/refractive-index-measurement-of-suspended-cells-using-opposed-view-digital-holographic-microscopy
#8
Juanjuan Zheng, Peng Gao, Xiaopeng Shao, G Ulrich Nienhaus
Opposed-view digital holographic microscopy (OV-DHM) with autofocusing and out-of-focus background suppression was demonstrated and applied to measure the refractive index (RI) of suspended HeLa cells. In OV-DHM, a specimen is illuminated from two sides in a 4π-like configuration. The generated two opposite-view object waves, which have orthogonal polarization orientations, interfere with a common reference wave, and the generated holograms are recorded by a CMOS camera. The image plane of the sample was determined by finding the minimal variation between the two object waves...
November 10, 2017: Applied Optics
https://www.readbyqxmd.com/read/29107993/nanoencapsulated-capsaicin-changes-migration-behavior-and-morphology-of-madin-darby-canine-kidney-cell-monolayers
#9
Mathias Kaiser, Luisa Pohl, Steffi Ketelhut, Lena Kastl, Christian Gorzelanny, Martin Götte, Jürgen Schnekenburger, Francisco M Goycoolea, Björn Kemper
We have developed a drug delivery nanosystem based on chitosan and capsaicin. Both substances have a wide range of biological activities. We investigated the nanosystem's influence on migration and morphology of Madin Darby canine kidney (MDCK-C7) epithelial cells in comparison to the capsaicin-free nanoformulation, free capsaicin, and control cells. For minimally-invasive quantification of cell migration, we applied label-free digital holographic microscopy (DHM) and single-cell tracking. Moreover, quantitative DHM phase images were used as novel stain-free assay to quantify the temporal course of global cellular morphology changes in confluent cell layers...
2017: PloS One
https://www.readbyqxmd.com/read/29082078/automated-red-blood-cells-extraction-from-holographic-images-using-fully-convolutional-neural-networks
#10
Faliu Yi, Inkyu Moon, Bahram Javidi
In this paper, we present two models for automatically extracting red blood cells (RBCs) from RBCs holographic images based on a deep learning fully convolutional neural network (FCN) algorithm. The first model, called FCN-1, only uses the FCN algorithm to carry out RBCs prediction, whereas the second model, called FCN-2, combines the FCN approach with the marker-controlled watershed transform segmentation scheme to achieve RBCs extraction. Both models achieve good segmentation accuracy. In addition, the second model has much better performance in terms of cell separation than traditional segmentation methods...
October 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/29047923/simple-and-flexible-phase-compensation-for-digital-holographic-microscopy-with-electrically-tunable-lens
#11
DingNan Deng, JunZheng Peng, WeiJuan Qu, Yu Wu, XiaoLi Liu, WenQi He, Xiang Peng
In a digital holographic microscopy (DHM) system, different microscope objectives (MOs) will introduce different phase distortions and thus lead to measurement errors. To address this problem, we present a simple and flexible method to compensate all phase distortions by introducing an electrically tunable lens (ETL) in the reference arm for a DHM system with multiple MOs. By exactly controlling the external currents of the ETL, we can change the reference wave front to match the wave front introduced by different MOs without complex alignment or additional numerical postprocessing manipulations...
July 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/29047904/cooperative-execution-of-auto-focusing-metrics-in-digital-lensless-holographic-microscopy-for-internal-structured-samples
#12
Carlos Trujillo, Jorge Garcia-Sucerquia
The cooperative execution of two metrics to automatically determine the best focal plane in digital lensless holographic microscopy (DLHM) is presented. This proposal is comprised of two stages: first, a quick coarse search over the whole reconstruction range by using Dubois's metric allows the finding of a range in which the best focal plane can be found. In a second stage, the modified enclosed energy (MEE) metric is used within the found range in the former stage to finely determine the best focal plane...
July 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/29047725/optimal-modified-lateral-shearing-interferometer-for-submicro-defects-measurement-of-transparent-objects
#13
Kwang-Beom Seo, Seung-Ho Shin
Transparent optical components, which are required for high-precision and high-performance, are made by a plastic injection molding method. This can cause inner defects to appear because of the difference in cooling rate and pressure. However, submicron inner defects, caused by the refractive index error, are extremely difficult to determine. Thus, digital holographic microscopy based on an optimal modified lateral shearing interferometer is proposed. This is to measure submicron defects in transparent objects, such as a defective microlens...
September 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/29047625/tolerance-of-holographic-polymer-dispersed-liquid-crystal-memory-for-gamma-ray-irradiation
#14
Akifumi Ogiwara, Minoru Watanabe, Yoshizumi Ito
The radiation-hardened characteristics of holographic polymer-dispersed liquid crystal (HPDLC) memory are discussed in the application for an optically reconfigurable gate array. The radiation experiments are conducted using a cobalt 60 gamma radiation source to examine the tolerance of a 100 Mrad total ionizing dose for the HPDLC memory. The optical properties are compared in the conditions before and after gamma-ray irradiation for the fabricated HPDLC gratings. The effects of gamma-ray irradiation on the internal grating structure are also investigated by polarization optical microscopy and scanning electron microscopy observations...
June 1, 2017: Applied Optics
https://www.readbyqxmd.com/read/29046061/three-dimensional-bacterial-behavior-near-dynamic-surfaces-formed-by-degradable-polymers
#15
Meng Qi, Qilei Song, Junpeng Zhao, Chunfeng Ma, Guangzhao Zhang, Xiangjun Gong
Understanding the behavior of bacteria near biodegradable surfaces is critical for the development of biomedical and antibiofouling materials. By using digital holographic microscopy (DHM), we investigated the three-dimensional (3D) behavior of Escherichia coli and Pseudomonas sp. in lipase-containing aquatic environments near dynamic surfaces constructed by biodegradable poly(ε-caprolactone) (PCL)-based polymers in real time. As the enzymatic degradation rate increases, the percentage of near-surface subdiffusive bacteria and consequently, the irreversible adhesion decreases...
November 1, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29044431/computational-imaging-of-sperm-locomotion
#16
Mustafa Ugur Daloglu, Aydogan Ozcan
Not only essential for scientific research, but also in the analysis of male fertility and for animal husbandry, sperm tracking and characterization techniques have been greatly benefiting from computational imaging. Digital image sensors, in combination with optical microscopy tools and powerful computers, have enabled the use of advanced detection and tracking algorithms that automatically map sperm trajectories and calculate various motility parameters across large data sets. Computational techniques are driving the field even further, facilitating the development of unconventional sperm imaging and tracking methods that do not rely on standard optical microscopes and objective lenses, which limit the field of view and volume of the semen sample that can be imaged...
August 1, 2017: Biology of Reproduction
https://www.readbyqxmd.com/read/29041487/3d-image-distortion-problem-in-digital-in-line-holographic-microscopy-and-its-effective-solution
#17
Heejung Lee, Philjun Jeon, Dugyoung Kim
Digital in-line holographic microscopy (DIHM) has attracted attention because of its simple but powerful three-dimensional (3D) imaging capability. To improve the spatial resolution, 3D image reconstruction algorithms use numerical magnification, which generates distortions in the generated images. We propose a method to overcome this problem by using the simple relation between the object and image positions in 3D space. Several holograms were taken while translating a resolution target at different axial positions by a motorized stage...
September 4, 2017: Optics Express
https://www.readbyqxmd.com/read/29041477/towards-a-holographic-approach-to-spherical-aberration-correction-in-scanning-transmission-electron-microscopy
#18
Vincenzo Grillo, Amir H Tavabi, Emrah Yucelen, Peng-Han Lu, Federico Venturi, Hugo Larocque, Lei Jin, Aleksei Savenko, Gian Carlo Gazzadi, Roberto Balboni, Stefano Frabboni, Peter Tiemeijer, Rafal E Dunin-Borkowski, Ebrahim Karimi
Recent progress in phase modulation using nanofabricated electron holograms has demonstrated how the phase of an electron beam can be controlled. In this paper, we apply this concept to the correction of spherical aberration in a scanning transmission electron microscope and demonstrate an improvement in spatial resolution. Such a holographic approach to spherical aberration correction is advantageous for its simplicity and cost-effectiveness.
September 4, 2017: Optics Express
https://www.readbyqxmd.com/read/29041474/coherent-noise-reduction-in-digital-holographic-microscopy-by-averaging-multiple-holograms-recorded-with-a-multimode-laser
#19
Feng Pan, Lizhi Yang, Wen Xiao
In digital holographic microscopy (DHM), it is undesirable to observe coherent noise in the reconstructed images. The sources of the noise are mainly the parasitic interference fringes caused by multiple reflections and the speckle pattern caused by the optical scattering on the object surface. Here we propose a noise reduction approach in DHM by averaging multiple holograms recorded with a multimode laser. Based on the periodicity of the temporal coherence of a multimode semiconductor laser, we acquire a series of holograms by changing the optical path length difference between the reference beam and object beam...
September 4, 2017: Optics Express
https://www.readbyqxmd.com/read/29041395/compact-and-stable-real-time-dual-wavelength-digital-holographic-microscopy-with-a-long-working-distance-objective
#20
Rongli Guo, Fan Wang
We propose a compact dual wavelength digital holographic Microscopy (DHM) based on a long working distance objective, which enabling quantitative phase imaging of opaque samples with extended measurement range in one shot. The compactness of the configuration is achieved by constructing a miniature modified Michelson interferometer between the objective and the sample, and as a result it provides higher temporal stability than conventional dual wavelength DHM. In the setup, the propagation directions of two reference beams of different wavelengths can be independently adjusted, and thus two off axis interferograms having orthogonal fringe directions can be simultaneously captured through a monochrome CCD camera...
October 2, 2017: Optics Express
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