On the relation between the wave aberration function and the phase transfer function for an incoherent imaging system with circular pupil

2001 ◽  
Vol 17 (2) ◽  
pp. 145-148 ◽  
Author(s):  
A.B. Utkin ◽  
R. Vilar ◽  
A.J. Smirnov
Keyword(s):  
Transfer Function ◽  
Phase Transfer ◽  
Imaging System ◽  
Incoherent Imaging ◽  
Wave Aberration

Applications of the phase transfer function of digital incoherent imaging systems

2012 ◽  
Vol 51 (4) ◽  
pp. A17 ◽  
Author(s):  
Vikrant R. Bhakta ◽  
Manjunath Somayaji ◽  
Marc P. Christensen
Keyword(s):  
Transfer Function ◽  
Phase Transfer ◽  
Imaging Systems ◽  
Incoherent Imaging

Imaging

2019 ◽  
pp. 382-434
Author(s):  
B. D. Guenther
Keyword(s):  
Transfer Function ◽  
Modulation Transfer Function ◽  
Noise Intensity ◽  
Imaging System ◽  
Optical Transfer Function ◽  
Modulation Transfer ◽  
Optical Aperture ◽  
System Properties ◽  
Incoherent Imaging ◽  
Optical Transfer

Treating an imaging system as a linear system and use llinear system properties to d iscuss both coherent and incoherent imaging. Use a one dimensional pin hole camera to study the theory of incoherent imaging. Two different criteria, Rayleigh and Sparrow, are used to define the resolution limits of the camera. From the simple theory define the optical transfer function and the modulation transfer function as appropriate characterizations of complex imaging systems. A review of the human imaging system emphasizes tits idfferences with man made cameras. Coherent imaging is based on Abbe’s theory of microscopy. A simple 4f imaging system can be used to understand how spatial resolution is limited by the optical aperture and by controlling the aperture, we can enhance the edges of an image or remove noise intensity noise on a plane wave. Apodizing the aperture allows astronomers to locate planents orbiting distant stars.

scholarly journals Effects of sampling on the phase transfer function of incoherent imaging systems

2011 ◽  
Vol 19 (24) ◽  
pp. 24609 ◽  
Author(s):  
Vikrant R. Bhakta ◽  
Manjunath Somayaji ◽  
Marc P. Christensen
Keyword(s):  
Transfer Function ◽  
Phase Transfer ◽  
Imaging Systems ◽  
Incoherent Imaging

Optimization of wavefront coding imaging system based on the phase transfer function

Optik ◽  
2016 ◽  
Vol 127 (3) ◽  
pp. 1148-1152 ◽  
Author(s):  
Vannhu Le ◽  
Zhigang Fan ◽  
Shouqian Chen ◽  
Dung Duong Quoc
Keyword(s):  
Transfer Function ◽  
Phase Transfer ◽  
Imaging System ◽  
Wavefront Coding

Electron Holography Improving Transmission Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 208-209
Author(s):  
Hannes Lichte
Keyword(s):  
Electron Microscopy ◽  
Transfer Functions ◽  
Imaging System ◽  
Spherical Aberration ◽  
Image Plane ◽  
Chromatic Aberration ◽  
Object Wave ◽  
Objective Lens ◽  
Electron Holography ◽  
Wave Aberration

Generally, the electron object wave o(r) is modulated both in amplitude and phase. In the image plane of an ideal imaging system we would expect to find an image wave b(r) that is modulated in exactly the same way, i. e. b(r) =o(r). If, however, there are aberrations, the image wave instead reads as b(r) =o(r) * FT(WTF) i. e. the convolution of the object wave with the Fourier transform of the wave transfer function WTF . Taking into account chromatic aberration, illumination divergence and the wave aberration of the objective lens, one finds WTF(R) = Echrom(R)Ediv(R).exp(iX(R)) . The envelope functions Echrom(R) and Ediv(R) damp the image wave, whereas the effect of the wave aberration X(R) is to disorder amplitude and phase according to real and imaginary part of exp(iX(R)) , as is schematically sketched in fig. 1.Since in ordinary electron microscopy only the amplitude of the image wave can be recorded by the intensity of the image, the wave aberration has to be chosen such that the object component of interest (phase or amplitude) is directed into the image amplitude. Using an aberration free objective lens, for X=0 one sees the object amplitude, for X= π/2 (“Zernike phase contrast”) the object phase. For a real objective lens, however, the wave aberration is given by X(R) = 2π (.25 Csλ3R4 + 0.5ΔzλR2), Cs meaning the coefficient of spherical aberration and Δz defocusing. Consequently, the transfer functions sin X(R) and cos(X(R)) strongly depend on R such that amplitude and phase of the image wave represent only fragments of the object which, fortunately, supplement each other. However, recording only the amplitude gives rise to the fundamental problems, restricting resolution and interpretability of ordinary electron images:

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