Article
Optics
Panu Hilden, Matti Kaivola, Andriy Shevchenko
Summary: This paper presents a theoretical framework for generating light sheets and introduces a practical method. The transverse profile of the light sheets can be shaped by modifying the spectrum of the light. This research is significant for beam-engineering technology and its applications.
Article
Optics
Cheng Tang, Jianping Li
Summary: In this study, we develop a computational optimization method for creating thin and wide light sheets that balance the trade-offs between thickness, non-diffracting range, and sidelobes.
Editorial Material
Optics
Giampaolo Pitruzzello
Summary: Light sheet microscopy allows rapid 3D imaging of biological specimens with minimal photodamage. Elizabeth Hillman from Columbia University discusses its capabilities, potential applications, and current limitations in an interview with Nature Photonics.
Article
Multidisciplinary Sciences
S. Francia, D. Shmal, S. Di Marco, G. Chiaravalli, J. F. Maya-Vetencourt, G. Mantero, C. Michetti, S. Cupini, G. Manfredi, M. L. DiFrancesco, A. Rocchi, S. Perotto, M. Attanasio, R. Sacco, S. Bisti, M. Mete, G. Pertile, G. Lanzani, E. Colombo, F. Benfenati
Summary: The researchers demonstrate that conjugated polymer nanoparticles can reinstate visual functions in degenerated and rewired retinas.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Gaoxiang Liu, Xiongtao Ruan, Daniel E. Milkie, Frederik Gorlitz, Matthew Mueller, Wilmene Hercule, Alison Killilea, Eric Betzig, Srigokul Upadhyayula
Summary: Lattice light sheet microscopy is excellent for noninvasive imaging of 3D dynamic processes within cells and embryos. However, its performance has recently been questioned compared to Gaussian sheets commonly used in light sheet microscopy. This study presents a theoretical and experimental analysis of different types of light sheet microscopy, showing that lattice light sheets offer significant improvements in resolution and photobleaching reduction. It also provides guidelines for selecting the appropriate light sheet and optimizing fluorescence usage for optimal resolution and minimal image artifacts and photodamage. A new type of harmonic balanced lattice light sheet is introduced, which improves performance across all spatial frequencies and allows for expanded fields of view.
Article
Physics, Applied
Jinhyeong Yoon, Jae-Yong Kim, Junhyeong Kim, Seokjin Hong, Berkay Neseli, Joonyong Park, Hyo-Hoon Park, Hamza Kurt
Summary: This paper presents the design and experimental demonstration of a cladding modulated waveguide Bragg grating (CMWBG) that supports transverse magnetic polarization for optical true time delay line (OTTDL) application. Compared to traditional waveguide Bragg gratings, the proposed structure has low propagation loss and high fabrication tolerance characteristics. The slow-light effect of the CMWBG was experimentally demonstrated.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Mbaye Diouf, Mitchell Harling, Murat Yessenov, Layton A. Hall, Ayman F. Abouraddy, Kimani C. Toussaint
Summary: The study introduces the concept of the space-time vector light sheet, demonstrating its characteristics of classical entanglement and maintaining the features of vector beams, such as near-diffraction-free propagation and self-healing. It also shows that the vector beam structure of the ST vector light sheet is maintained in both subluminal and superluminal regimes.
Article
Optics
Ahmed H. Dorrah, Priyanuj Bordoloi, Vinicius S. de Angelis, Jhonas O. de Sarro, Leonardo A. Ambrosio, Michel Zamboni-Rached, Federico Capasso
Summary: A stack of longitudinal 2D light sheets is proposed for generating 3D holographic images with improved depth perception. This new hologram projection method allows for continuous reconstruction of the object along the optical path by projecting 2D scenes onto perpendicular sheets. By decomposing the target scene into non-diffracting pencil-like beams, high fidelity 3D objects can be constructed with low crosstalk. This computer-generated holography opens new possibilities for realistic 3D holography in wearable smart glasses, portable devices, and wide-angle volumetric displays.
Article
Optics
Lijia Song, Tangnan Chen, Weixi Liu, Hongxuan Liu, Yingying Peng, Zejie Yu, Huan Li, Yaocheng Shi, Daoxin Dai
Summary: This study proposes a novel design for calibration-free 2 x 2 and N x N MZSs, which reduces the random phase imbalance by optimizing the width of arm waveguides and incorporating mode filters. The fabricated MZSs show significant improvement in performance without the need for calibration, paving the way for large-scale N x N MZSs in next-generation silicon photonics.
PHOTONICS RESEARCH
(2022)
Article
Engineering, Environmental
Sang Bin Jeong, Dong Uk Lee, Byeong Jin Lee, Ki Joon Heo, Dong Won Kim, Gi Byoung Hwang, Alexander J. MacRobert, Jae Hak Shin, Hyun Sik Ko, Se Kye Park, Yong Suk Oh, See Jo Kim, Dong Yun Lee, Seung-Bok Lee, Inyong Park, Sang Bok Kim, Bangwoo Han, Jae Hee Jung, Dong Yun Choi
Summary: This study presents a nanocoating process for manufacturing antimicrobial and reusable mask filters. The nanocoating endows the filters with photobiocidal activity, triboelectric filtration capability, and washability, while maintaining their performance and durability under light irradiation. After washes with detergent, the filters still maintain their antimicrobial and filtration performance. This nanocoating provides a practical solution for tackling the COVID-19 pandemic.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Nanoscience & Nanotechnology
Alejandro Rojas Gomez, Laura K. Acosta, Josep Ferre-Borrull, Abel Santos, Lluis F. Marsal
Summary: Gold-coated gradient-index filters based on nano-porous anodic alumina were studied to investigate the properties and applications of Tamm plasmons. The quality factor of Tamm resonance can be improved by tuning the features of the dielectric mirror and the thickness of the porous gold coating layer. The Tamm resonances in Au-coated NAA-GIFs are weak due to the narrow bands of the photonic crystal structures, but become better resolved and more intense after broadening of the photonic stopband. The hybrid Tamm porous system provides a nanoporous structure that can be readily tailored for various photonic technologies.
ACS APPLIED NANO MATERIALS
(2023)
Article
Physics, Applied
Amirreza Mahigir, Georgios Veronis
Summary: This study introduces wavelength-scale light coupling structures and switches for plasmonic coaxial waveguides. By optimizing single-slit, double-slit, and triple-slit structures, the coupling efficiency is enhanced, and different propagation modes can be generated. Additionally, the study explores outcoupling structures for light extraction and utilizing proper angle excitation for specific modes in plasmonic coaxial waveguides.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Sakila S. Jayaweera, Chamira U. S. Edussooriya, Chamith Wijenayake, Panajotis Agathoklis, Len T. Bruton
Summary: This letter introduces a method for simultaneous refocusing of multiple volumetric regions in light fields, utilizing a 4-D sparse FIR filter. Experimental results show a 63% reduction in computational complexity compared to traditional methods, with negligible degradation in the accuracy of refocused images.
IEEE SIGNAL PROCESSING LETTERS
(2021)
Article
Optics
Anne -laure Fehrembach, Evgueni Popov, Elizabeth Hemsley, Antoine Monmayrant, Olivier Gauthier-lafaye, Stephane Calvez
Summary: This article reports on the design of cavity-resonator integrated grating couplers for second-harmonic generation. By using two ridges with different widths as the base pattern, high Q-factors are achieved in a structure that is not challenging to fabricate. Careful selection of structure parameters can reduce transition losses between different sections and improve conversion efficiency.
Article
Astronomy & Astrophysics
Adam Coogan, Thomas D. P. Edwards, Horng Sheng Chia, Richard N. George, Katherine Freese, Cody Messick, Christian N. Setzer, Christoph Weniger, Aaron Zimmerman
Summary: This study proposes a new method for generating template banks using automatic differentiation and demonstrates its efficiency and accuracy. By combining random template placement and Monte Carlo methods, search-ready template banks for frequency-domain waveforms can be rapidly generated. The study also suggests that differentiable waveforms can accelerate stochastic placement algorithms.
Article
Optics
Colin J. R. Sheppard, Artemi Bendandi, Aymeric Le Gratiet, Alberto Diaspro
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2020)
Article
Optics
Rong Su, Jeremy Coupland, Colin Sheppard, Richard Leach
Summary: Surface topography measuring interference microscopy is a 3D imaging technique that quantitatively analyzes industrial and biomedical specimens. This paper presents a unified theoretical framework for 3D image formation in interference microscopy and discusses the linear relationship between scattered amplitude and surface topography. The study shows that the 3D filtering process can be reduced to two dimensions for near planar surfaces.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2021)
Article
Biochemical Research Methods
Aymeric Le Gratiet, Artemi Bendandi, Colin J. R. Sheppard, Alberto Diaspro
Summary: Many significant improvements in resolution in optical microscopy techniques are achieved by reducing scattering effects. Polarimetry-based imaging allows discrimination between scattering phenomena and experimental noise, providing additional structural information of a sample. The use of coherency matrix and related decompositions leads to improved imaging contrast without requiring complicated algebraic operations or prior knowledge of the sample.
JOURNAL OF BIOPHOTONICS
(2021)
Review
Multidisciplinary Sciences
Colin J. R. Sheppard
Summary: Structured illumination microscopy and image scanning microscopy are two rapidly growing microscopic techniques that can enhance transverse spatial resolution and/or improve axial imaging performance. This article reviews the history and principles of these techniques and compares the imaging properties of the two methods.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Optics
Colin J. R. Sheppard, Marco Castello, Giorgio Tortarolo, Eli Slenders, Takahiro Deguchi, Sami Koho, Paolo Bianchini, Giuseppe Vicidomini, Alberto Diaspro
Summary: In image scanning microscopy, a detector array is used instead of a pinhole in a confocal microscope, allowing for maximum likelihood restoration and compensation for aberrations. Illumination with a vortex doughnut beam is investigated as an example of aberration, leading to a more compact point spread function, higher resolution, and signal level compared to conventional microscopy.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2021)
Article
Optics
Colin J. R. Sheppard, Artemi Bendandi, Aymeric Le Gratiet, Alberto Diaspro
Summary: This article reexamines the measures of purity for 3D partially polarized fields, focusing on the separation of circularly and linearly polarized contributions and introducing a new degree of total linear polarization. Explicit expressions for the characteristic decomposition based on coherency matrix elements are presented, including the special case of an intrinsic coherency matrix. The parameterization of the coherency matrix in terms of ellipticity, and the directions of the ellipse normal and major axis are investigated. The discussion also includes phase consistency and provides a comprehensive collection of results regarding intrinsic polarization properties.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2022)
Review
Chemistry, Multidisciplinary
Colin J. R. Sheppard
Summary: Various optical methods of super-resolution microscopy, including confocal microscopy, structured illumination, nonlinear microscopy, and image scanning microscopy, are reviewed for their ability to observe delicate biological samples without strong invasive interaction. The discussion also covers the concepts of resolution and the basic principles of superresolution.
APPLIED SCIENCES-BASEL
(2021)
Article
Optics
Colin J. R. Sheppard, Artemi Bendandi, Aymeric Le Gratiet, Alberto Diaspro
Summary: Depolarization is an important contrast mechanism in biological and medical imaging. This paper presents a historical review on polarization algebra, measures of depolarization, and purity spaces, and discusses their connections with the eigenvalues of the coherency matrix. The advantages of a barycentric eigenvalue space are outlined, and a new parameter called diattenuation-corrected purity is introduced. The use of a combination of eigenvalues of coherency matrices to specify the depolarization condition is proposed. The relationships between optical and polarimetric radar formalisms are also reviewed.
Review
Optics
Colin J. R. Sheppard, Artemi Bendandi, Aymeric Le Gratiet, Alberto Diaspro
Summary: Many books on polarization provide tables of Mueller matrices. The coherency matrix is useful for interpreting Mueller matrices. We present a table of Mueller matrices M, coherency matrices C, and coherency matrix factors F for different polarization components and systems, along with simplified forms for certain cases.
Article
Optics
Colin J. R. Sheppard, Marco Castello, Giorgio Tortarolo, Alessandro Zunino, Eli Slenders, Paolo Bianchini, Giuseppe Vicidomini, Alberto Diaspro
Summary: This article reviews the properties of signal strength and integrated intensity in a scanned imaging system, with a particular focus on confocal imaging systems, including image scanning microscopy. The integrated intensity, which represents the image of a uniform planar object rather than the peak of the point spread function, serves as a measure of the flux in an image. Analytic expressions are provided for the intensity in the detector plane for a uniform volume object and its resulting background. The article also demonstrates the variation in integrated intensity with defocus for an offset point detector, which remains unchanged regardless of pixel reassignment. Furthermore, it reveals that the intensity in the detector plane carries defocus information, and simple processing of recorded data can enhance optical sectioning and background rejection.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2023)
Article
Multidisciplinary Sciences
Giorgio Tortarolo, Alessandro Zunino, Francesco Fersini, Marco Castello, Simonluca Piazza, Colin J. R. Sheppard, Paolo Bianchini, Alberto Diaspro, Sami Koho, Giuseppe Vicidomini
Summary: The feasibility of super-resolution microscopy for live and thick sample imaging is limited. We propose a method that combines ISM and STED techniques to achieve high-resolution imaging without introducing photodamage and background degradation.
NATURE COMMUNICATIONS
(2022)
Article
Biochemical Research Methods
Wei Zheng, Shan S. Kou, Colin J. R. Sheppard, Maitreyee Roy
Summary: Optical coherence microscopy (OCM) is a variant of OCT that uses a high-numerical aperture lens. Full-field OCM (FF-OCM) is an emerging non-invasive, label-free, interferometric technique for micron-scale imaging of surface structures or semi-transparent biomedical objects. In this study, a unique geometric phase-shifter based on ferroelectric liquid crystal technology is demonstrated to achieve achromatic phase-shifting for rapid three-dimensional imaging in a FF-OCM system, by imaging tissues and cells.
BIOMEDICAL OPTICS EXPRESS
(2023)
Article
Optics
Colin J. R. Sheppard, Marco Castello, Giorgio Tortarolo, Alessandro Zunino, Eli Slenders, Paolo Bianchini, Giuseppe Vicidomini, Alberto Diaspro
Summary: We discuss the properties of signal strength and integrated intensity in two-photon excitation confocal microscopy and image scanning microscopy. The resolution, optical sectioning, and background rejection are all improved over nonconfocal two-photon microscopy. Replacing the pinhole of confocal two-photon microscopy with a detector array increases the peak intensity of the point spread function. The outer pixels of a detector array give signals from defocused regions, and thus the processing of these, such as through subtraction, can further improve optical sectioning and background rejection.
Article
Optics
Colin J. R. Sheppard, Marco Castello, Giorgio Tortarolo, Alessandro Zunino, Eli Slenders, Paolo Bianchini, Giuseppe Vicidomini, Alberto Diaspro
Summary: This article discusses the effects of image scanning microscopy using doughnut beam illumination on signal strength and integrated intensity properties. Doughnut beam illumination provides better optical sectioning and background rejection compared to Airy disk illumination. The outer pixels of a detector array capture signals from defocused regions, and digital processing of these signals can further enhance optical sectioning and background rejection in a single in-focus scan.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Giorgio Tortarolo, Simonluca Piazza, Andrea Bucci, Paolo Bianchini, Colin J. R. Sheppard, Alberto Diaspro, Eli Slenders, Sami Koho, Marco Castello, Giuseppe Vicidomini
2021 CONFERENCE ON LASERS AND ELECTRO-OPTICS EUROPE & EUROPEAN QUANTUM ELECTRONICS CONFERENCE (CLEO/EUROPE-EQEC)
(2021)