FESDIF -- Finite Element Scalar Diffraction theory code

Diffraction patterns of a brass tube and a hard rubber rod, each a cylinder of 1 in. diameter, in a nearly plane beam of square-wave modulated 3 cm. waves with electric vector parallel to the cylinder axis, have been measured in several planes transverse to the incident beam direction. Experimental results for the conducting cylinder agree closely with calculations based on scalar diffraction theory. Patterns of the dielectric rod show a pronounced central peak immediately behind the rod and other intensity effects differing from the conducting cylinder patterns, particularly in the vicinity of the shadow.

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Relationship between the technique of integral equation and Kirchhoff approximation in scalar diffraction theory

Optical Fibers and Their Applications 2020 ◽

10.1117/12.2569787 ◽

2020 ◽

Author(s):

Grygorij S. Tymchik ◽

Maryna V. Filippova ◽

Oleg S. Bezverkhyi ◽

Waldemar Wójcik ◽

Bakhyt Yeraliyeva ◽

...

Keyword(s):

Integral Equation ◽

Diffraction Theory ◽

Kirchhoff Approximation ◽

Scalar Diffraction ◽

Scalar Diffraction Theory

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Multidither coherent optical adaptive technique for deep tissue two-photon microscopy

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545819420033 ◽

2019 ◽

Vol 12 (04) ◽

pp. 1942003 ◽

Cited By ~ 1

Author(s):

Biwei Zhang ◽

Wei Gong ◽

Chenxue Wu ◽

Lejia Hu ◽

Xinpei Zhu ◽

...

Keyword(s):

Adaptive Optics ◽

Diffraction Theory ◽

Fluorescence Signal ◽

Two Photon Microscopy ◽

Scalar Diffraction ◽

Two Photon ◽

Scalar Diffraction Theory ◽

Adaptive Technique ◽

Photon Imaging ◽

Two Photon Imaging

Two-photon microscopy normally suffers from the scattering of the tissue in biological imaging. Multidither coherent optical adaptive technique (COAT) can correct the scattered wavefront in parallel. However, the determination of the corrective phases may not be completely accurate using conventional method, which undermines the performance of this technique. In this paper, we theoretically demonstrate a method that can obtain more accurate corrective phases by determining the phase values from the square root of the fluorescence signal. A numerical simulation model is established to study the performance of adaptive optics in two-photon microscopy by combining scalar diffraction theory with vector diffraction theory. The results show that the distortion of the wavefront can be corrected more thoroughly with our method in two-photon imaging. In our simulation, with the scattering from a 450-[Formula: see text]m-thick mouse brain tissue, excitation focal spots with higher peak-to-background ratio (PBR) and images with higher contrast can be obtained. Hence, further enhancement of the multidither COAT correction performance in two-photon imaging can be expected.

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