Zobrazeno 1 - 10
of 604
pro vyhledávání: '"J R Sheppard"'
Autor:
Colin J. R. Sheppard
Publikováno v:
Photonics, Vol 11, Iss 4, p 346 (2024)
In this paper, diffraction of scalar waves by a screen with a circular aperture is explored, considering the incidence of either a collimated beam or a focused wave, a historical review of the development of the theory is presented, and the introduct
Externí odkaz:
https://doaj.org/article/dc86b1e8dbf844e8b3a2f8da7d44e06b
Autor:
Giorgio Tortarolo, Alessandro Zunino, Francesco Fersini, Marco Castello, Simonluca Piazza, Colin J. R. Sheppard, Paolo Bianchini, Alberto Diaspro, Sami Koho, Giuseppe Vicidomini
Publikováno v:
Nature Communications, Vol 13, Iss 1, Pp 1-14 (2022)
Super-resolution microscopy techniques can be challenging for live cells and thick samples. Here, the authors propose a method to reduce beam intensity and remove out-of-focus fluorescence background in image-scanning microscopy (ISM) and its combina
Externí odkaz:
https://doaj.org/article/b3f52a050bed4a879c1cfb1ec738f0b6
Autor:
Colin J. R. Sheppard, Miguel A. Porras
Publikováno v:
Photonics, Vol 10, Iss 9, p 1011 (2023)
The connections between Laguerre–Gauss and Bessel–Gauss beams, and between Hermite–Gauss and cosine-Gauss beams are investigated. We review different asymptotic expressions for generalized Laguerre and Hermite polynomials of large radial/transv
Externí odkaz:
https://doaj.org/article/3230355c7ca44c5ba38fc42edab5a8d9
Autor:
Colin J. R. Sheppard, Marco Castello, Giorgio Tortarolo, Alessandro Zunino, Eli Slenders, Paolo Bianchini, Giuseppe Vicidomini, Alberto Diaspro
Publikováno v:
Photonics, Vol 10, Iss 5, p 601 (2023)
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
Externí odkaz:
https://doaj.org/article/d3aa542242524380a08c903ddfd46db2
Publikováno v:
Photonics, Vol 9, Iss 6, p 394 (2022)
Many books on polarization give tables of Mueller matrices. The coherency matrix has been found useful for interpretetion of the Mueller matrix. Here we give a table of Mueller matrices M, coherency matrices C, and coherency matrix factors F for diff
Externí odkaz:
https://doaj.org/article/225c329b91794a8581785b5a65ee99ba
Publikováno v:
Photonics, Vol 9, Iss 2, p 88 (2022)
Depolarization has been found to be a useful contrast mechanism in biological and medical imaging. The Mueller matrix can be used to describe polarization effects of a depolarizing material. An historical review of relevant polarization algebra, meas
Externí odkaz:
https://doaj.org/article/c5d2cc0ae1e348d6ada2c0037d4c56bd
Autor:
Colin J. R. Sheppard
Publikováno v:
Applied Sciences, Vol 11, Iss 19, p 8981 (2021)
Optical methods of super-resolution microscopy, such as confocal microscopy, structured illumination, nonlinear microscopy, and image scanning microscopy are reviewed. These methods avoid strong invasive interaction with a sample, allowing the observ
Externí odkaz:
https://doaj.org/article/102c3cffccff4a4c976de2e70347ac31
Measures of purity for 3D partially polarized fields, and in particular, the separation into circularly and linearly polarized contributions, are reexamined, and a new degree of total linear polarization introduced. Explicit expressions for the chara
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::61e86f50c974a1c5169852bd28329056
http://hdl.handle.net/11567/1075168
http://hdl.handle.net/11567/1075168
Autor:
Colin J. R. Sheppard, Marco Castello, Giorgio Tortarolo, Alessandro Zunino, Eli Slenders, Paolo Bianchini, Giuseppe Vicidomini, Alberto Diaspro
Publikováno v:
Journal of the Optical Society of America A. 40:138
The properties of signal strength and integrated intensity in a scanned imaging system are reviewed. These prop-erties are especially applied to confocal imaging systems, including image scanning microscopy. The integrated intensity, equal to the ima
Publikováno v:
Journal of Innovative Optical Health Sciences, Vol 7, Iss 5, Pp 1440001-1-1440001-27 (2014)
Optical microscopy has become an indispensable tool for visualizing sub-cellular structures and biological processes. However, scattering in biological tissues is a major obstacle that prevents high-resolution images from being obtained from deep reg
Externí odkaz:
https://doaj.org/article/9cb1a07258cd44f280e262ae2b88d0b4