Space-variant polarization manipulation for far-field polarimetry by use of subwavelength dielectric gratings

2005 ◽  
Vol 30 (17) ◽  
pp. 2245 ◽  
Author(s):  
Yuri Gorodetski ◽  
Gabriel Biener ◽  
Avi Niv ◽  
Vladimir Kleiner ◽  
Erez Hasman
Keyword(s):  
Far Field ◽  
Dielectric Gratings ◽  
Space Variant

The analysis of near and far field pattern through mode analysis and FFT in a finite periodic dielectric gratings

2015 ◽  
Vol 17 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Tae-Bong Lee ◽  
Min-Nyeon Kim
Keyword(s):  
Near Field ◽  
Bloch Wave ◽  
Wave Number ◽  
Mode Analysis ◽  
Field Pattern ◽  
Far Field ◽  
Content Type ◽  
Coupled Method ◽  
Field Patterns ◽  
Dielectric Gratings

Purpose – The purpose of this paper is to analyze far and near field emitted field patterns through more exact calculation of the modes formed in finite periodic dielectric gratings. Design/methodology/approach – For the mode calculation, equations are newly defined by applying vertical boundary condition on the assumption that transverse electric modes are generated in the structure. After finding modes, near field patterns are calculated using the wave number and coefficient of the mode. Findings – Additionally, the results from these calculations are compared with that of the rigorous-coupled method. Finally, far field patterns are derived by applying fast Fourier transform to near field patterns and also compared with the results of rigorous-coupled method. Research limitations/implications – For convenience of coordinate, we use rectangular coordinate, though the shape of radome is a hemisphere. Practical implications – In this paper, the authors derive more exact near field patterns without the assumption of infiniteness so that these results can be used practically for a making real frequency-selective structure. Originality/value – Conventional periodic finite dielectric gratings analysis has been done using Floquet–Bloch wave theory, coupled-mode, rigorous-coupled method which is based on the assumption of infiniteness of the structure.

Formation of discrete space-variant subwavelength dielectric gratings for polarimetric measurements

2005 ◽  
Author(s):  
Gabriel Biener ◽  
Avi Niv ◽  
Yuri Gorodetski ◽  
Vladimir Kleiner ◽  
Erez Hasman
Keyword(s):  
Discrete Space ◽  
Dielectric Gratings ◽  
Space Variant

Computer-generated infrared depolarizer using space-variant subwavelength dielectric gratings

2003 ◽  
Vol 28 (16) ◽  
pp. 1400 ◽  
Author(s):  
Gabriel Biener ◽  
Avi Niv ◽  
Vladimir Kleiner ◽  
Erez Hasman
Keyword(s):  
Dielectric Gratings ◽  
Space Variant

Polarization Talbot self-imaging with computer-generated, space-variant subwavelength dielectric gratings

2002 ◽  
Vol 41 (25) ◽  
pp. 5218 ◽  
Author(s):  
Ze’ev Bomzon ◽  
Avi Niv ◽  
Gabriel Biener ◽  
Vladimir Kleiner ◽  
Erez Hasman
Keyword(s):  
Dielectric Gratings ◽  
Space Variant

Possible applications of fraunhofer holography in high resolution electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 222-223 ◽  
Author(s):  
N. Bonnet ◽  
M. Troyon ◽  
P. Gallion
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Transfer Function ◽  
Radiation Damage ◽  
High Resolution Electron Microscopy ◽  
Far Field ◽  
Field Region ◽  
Crystalline Materials ◽  
Resolution Electron ◽  
The Ideal

Two main problems in high resolution electron microscopy are first, the existence of gaps in the transfer function, and then the difficulty to find complex amplitude of the diffracted wawe from registered intensity. The solution of this second problem is in most cases only intended by the realization of several micrographs in different conditions (defocusing distance, illuminating angle, complementary objective apertures…) which can lead to severe problems of contamination or radiation damage for certain specimens.Fraunhofer holography can in principle solve both problems stated above (1,2). The microscope objective is strongly defocused (far-field region) so that the two diffracted beams do not interfere. The ideal transfer function after reconstruction is then unity and the twin image do not overlap on the reconstructed one.We show some applications of the method and results of preliminary tests.Possible application to the study of cavitiesSmall voids (or gas-filled bubbles) created by irradiation in crystalline materials can be observed near the Scherzer focus, but it is then difficult to extract other informations than the approximated size.

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