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pro vyhledávání: '"Colin J R Sheppard"'
Autor:
Colin J. R. Sheppard
Publikováno v:
Photonics, Vol 11, Iss 10, p 913 (2024)
The effects of various properties on the tight focusing of light are considered. In particular, polarization of the incident field is an important consideration. Plots are presented for the variations in the focal intensity, and the area and volume o
Externí odkaz:
https://doaj.org/article/b7a1f4d817f74a83aebac8ce3b3e3a9f
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
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:
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