IMPROVE POINT SPREAD FUNCTION BY USING GAUSSIAN FILTER WITH SINGLE HEXAGONAL APERTURE

We study the effect of Gaussian filter on the point spread function (psf) for a single hexagonal aperture for diffraction limit system and by inserting a coma aberration (w31=0.25 and 0.5). Also we derived the point spread function for a single hexagonal aperture and when there is a Gaussian filter with different values in width used. the different values of coma aberration was study ,we notice a decrease in intensity and secondary peaks of psf . The pulse to noise ratio increases with the width of the Gaussian filter increases.

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Influence of signal-to-noise ratio and point spread function on limits of superresolution

10.1117/12.586574 ◽

2005 ◽

Cited By ~ 7

Author(s):

Tuan Q. Pham ◽

Lucas J. van Vliet ◽

Klamer Schutte

Keyword(s):

Point Spread Function ◽

Signal To Noise Ratio ◽

Signal To Noise ◽

Point Spread ◽

Spread Function ◽

Noise Ratio

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Off-axis electron holography in an aberration-corrected transmission electron microscope

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2009.0126 ◽

2009 ◽

Vol 367 (1903) ◽

pp. 3773-3793 ◽

Cited By ~ 20

Author(s):

Hannes Lichte ◽

Dorin Geiger ◽

Martin Linck

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Point Spread Function ◽

Signal To Noise Ratio ◽

Electron Holography ◽

Signal To Noise ◽

Point Spread ◽

Transmission Electron ◽

Spread Function ◽

Noise Ratio

Electron holography allows the reconstruction of the complete electron wave, and hence offers the possibility of correcting aberrations. In fact, this was shown by means of the uncorrected CM30 Special Tübingen transmission electron microscope (TEM), revealing, after numerical aberration correction, a resolution of approximately 0.1 nm, both in amplitude and phase. However, it turned out that the results suffer from a comparably poor signal-to-noise ratio. The reason is that the limited coherent electron current, given by gun brightness, has to illuminate a width of at least four times the point-spread function given by the aberrations. As, using the hardware corrector, the point-spread function shrinks considerably, the current density increases and the signal-to-noise ratio improves correspondingly. Furthermore, the phase shift at the atomic dimensions found in the image plane also increases because the collection efficiency of the optics increases with resolution. In total, the signals of atomically fine structures are better defined for quantitative evaluation. In fact, the results achieved by electron holography in a Tecnai F20 Cs-corr TEM confirm this.

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The Effect of adding First Order Aberrations To Third Order Aberrations on Point Spread Function for Triangular Aperture

Journal of Kufa Physics ◽

10.31257/2018/jkp/2020/120104 ◽

2020 ◽

Vol 12 (01) ◽

pp. 23-31

Author(s):

Widad Hamza Tarkhan ◽

◽

Ahlam Habeeb Hussien ◽

Areej Saeed Abdul Shaheed ◽

◽

...

Keyword(s):

Optical System ◽

Point Spread Function ◽

Spherical Aberration ◽

Strehl Ratio ◽

Third Order ◽

First Order ◽

Point Spread ◽

Spread Function ◽

Coma Aberration ◽

Angle Of Rotation

In this work, Point Spread Function (PSF) for triangular aperture was studied, in case of ideal optical system, also in case of presence first order aberrations )focal error and tilt aberration) and third order aberrations (spherical ,coma, and astigmatism aberrations) individually, and for the same values of aberration factor )W=0.1λ …..0.5 λ ) for angle of rotation (ѱ =0). First order aberrations were added to third order aberrations, to obtain the best balance and to reduce the curve width of the (PSF), and to increase the Strehl ratio, like adding a tilt aberration to the coma aberration and adding focal error to spherical aberration and astigmatism aberration. There are some aberrations effects impact negatively on point spread function, such as focal error with coma aberration and tilt aberration with spherical aberration.

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Point Spread Function For Elliptical Aperture Inclined at ï°/4 angle with x-axis

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v5i2.1937 ◽

2014 ◽

Vol 5 (2) ◽

pp. 767-777

Author(s):

Sundus Y. Hasan ◽

Widad H. Tarkhan

Keyword(s):

Point Spread Function ◽

Spherical Aberration ◽

Point Spread ◽

Spread Function ◽

Different Types ◽

Coma Aberration

Point spread function (PSF) for inclined elliptical aperture with an angle equal to p/4 with x-axis has been studied, by taking new coordinates m and n which are rotated by an angle p/4 to x and y- axes.The properties of the obtained image have been found in different cases, for diffraction limited system and different types of aberrations, like focus error, spherical aberration and coma aberration.

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