Gaussian Beam Summation Representation of Beam Diffraction by an Impedance Wedge: A 3D Electromagnetic Formulation Within the Physical Optics Approximation

2012 ◽  
Vol 60 (12) ◽  
pp. 5843-5858 ◽  
Author(s):  
Michael Katsav ◽  
Ehud Heyman
Keyword(s):  
Gaussian Beam ◽  
Physical Optics ◽  
Impedance Wedge ◽  
Physical Optics Approximation ◽  
Beam Diffraction

scholarly journals Gaussian beam diffraction in inhomogeneous and logarithmically saturable nonlinear media

Open Physics ◽  
2012 ◽  
Vol 10 (4) ◽  
Author(s):  
Pawel Berczynski
Keyword(s):  
Gaussian Beam ◽  
Wave Front ◽  
Analytical Methods ◽  
Cylindrical Symmetry ◽  
Nonlinear Media ◽  
First Order ◽  
Self Focusing ◽  
Complex Curvature ◽  
Numerical And Analytical Methods ◽  
Beam Diffraction

AbstractThe method of paraxial complex geometrical optics (PCGO) is presented, which describes Gaussian beam (GB) diffraction and self-focusing in smoothly inhomogeneous and nonlinear saturable media of cylindrical symmetry. PCGO reduces the problem of Gaussian beam diffraction in nonlinear and inhomogeneous media to the system of the first order ordinary differential equations for the complex curvature of the wave front and for GB amplitude, which can be readily solved both analytically and numerically. As a result, PCGO radically simplifies the description of Gaussian beam diffraction in inhomogeneous and nonlinear media as compared to the numerical and analytical methods of nonlinear optics. The power of PCGO method is presented on the example of Gaussian beam evolution in logarithmically saturable medium with either focusing and defocusing refractive profile. Besides, the influence of initial curvature of the wave front on GB evolution in nonlinear saturable medium is discussed in this paper.

Light scattering by ice crystals of cirrus clouds: From exact numerical methods to physical-optics approximation

2017 ◽  
Vol 195 ◽  
pp. 132-140 ◽  
Author(s):  
Alexander Konoshonkin ◽  
Anatoli Borovoi ◽  
Natalia Kustova ◽  
Hajime Okamoto ◽  
Hiroshi Ishimoto ◽  
...  
Keyword(s):  
Light Scattering ◽  
Numerical Methods ◽  
Cirrus Clouds ◽  
Ice Crystals ◽  
Physical Optics ◽  
Physical Optics Approximation

Null field approach to scalar diffraction II. Approximate methods

1977 ◽  
Vol 287 (1339) ◽  
pp. 79-95 ◽  
Keyword(s):  
Computational Procedure ◽  
Diffraction Theory ◽  
Field Method ◽  
Physical Optics ◽  
Surface Source ◽  
Approximate Methods ◽  
Null Field ◽  
Physical Optics Approximation ◽  
Definition Of ◽  
Scattered Fields

We develop from our generalized null field method a generalization of the Kirchhoff, or physical optics, approach to diffraction theory. Corresponding to each particular null field method there is a corresponding physical optics approximation, which becomes exact when one of the coordinates being used is constant over the surface of the scattering body. We show how to improve these approximations by a computational procedure which is more efficient than those introduced in the previous paper. The reradiations from our physical optics surface sources more nearly satisfy the extinction theorem the deeper they penetrate the interiors of scattering bodies. We find that we have to introduce a new definition of the parts of a body’s surface that are directly illuminated and shadowed, and we suggest that this may be more apposite in general than the usual definition. The computational examples presented herein indicate that useful approximations to surface source densities are obtained in the umbra and penumbra of bodies. These examples also show that our scattered fields are in several particulars superior to those obtained from the conventional Kirchhoff approach. It is important to choose that physical optics approximation most appropriate for the scattering body in question.

Sign in / Sign up

Export Citation Format

Share Document