Browsing by Author "Umul, Yusuf Z."
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Correction Comment On "A Survey of The New Proposal About The Photon Momentum" (vol 148, pg 342, 2017)(Elsevier Gmbh, Urban & Fischer verlag, 2018) Umul, Yusuf Z.; Umul, Yusuf Ziya; 42699Article Diffraction of evanescent plane waves by a resistive half-plane(Optical Soc Amer, 2007) Umul, Yusuf Z.; Umul, Yusuf Ziya; 42699Diffraction of evanescent plane waves by a resistive half-plane is examined. The scattering integrals are constructed with the modified theory of physical optics. These integrals are evaluated uniformly by using an unusual method. The scattered fields of evanescent waves are obtained by giving the angle of incidence a complex value. The diffracted waves are plotted numerically for different parameters of the incident field. (c) 2007 Optical Society of America.Article Diffraction of homogeneous and inhomogeneous plane waves by a planar junction between perfectly conducting and impedance half-planes(Optical Soc Amer, 2007) Umul, Yusuf Z.; Umul, Yusuf Ziya; 42699The problem of diffraction of homogeneous and inhomogeneous plane waves at the discontinuity formed by perfectly conducting and impedance half-planes is examined by the method of modified theory of physical optics (MTPO). The MTPO integral of the reflected scattered waves by the perfectly conducting half-plane is reconstructed in order to include the effect of the diffracted wave coming from the edge of the impedance halfplane. The integrals are evaluated by a uniform asymptotic method. The results are plotted numerically and compared with the literature. (C) 2007 Optical Society of AmericaArticle Edge-dislocation waves in the diffraction process by an impedance half-plane(Optical Soc Amer, 2007) Umul, Yusuf Z.; Umul, Yusuf Ziya; 42699Edge-dislocation waves, created in the diffraction of plane waves by an impedance half-plane, are examined by the method of modified theory of physical optics. The integrals, obtained by a related technique, are decomposed according to their boundaries and evaluated by using uniform asymptotic methods. The results are plotted and are investigated numerically. (c) 2007 Optical Society of AmericaArticle General formulation of the scattered matter waves by a quantum shutter(2009) Umul, Yusuf Z.; 42699The scattering process of matter waves by a quantum shutter is investigated by using the spectrum integral representation. The scattered fields are expressed in terms of the Fresnel function. It is shown that the obtained equation gives the Moshinsky function for a one dimensional problem of the plane wave. Also a general integral representation is derived for two dimensional problems. The scattering of matter waves for some special wave-packets are examined analytically and numerically. © TÜBİTAK.Article Modified Theory of Physical Optics Approach to Diffraction by an Interface between PEMC and Absorbing Half-Planes(2021) Umul, Yusuf Z.; 42699The scattering of electromagnetic plane waves by an interface, located between perfect electromagnetic conductor and absorbing half-planes, is investigated. The perfect electromagnetic conductor half-plane is divided into perfect electric conductor and perfect magnetic conductor half-screens. The same decomposition is done for the absorbing surface. Then four different geometries are defined according to this approach. The scattered fields by the four sub-problems are obtained with the aid of the modified theory of physical optics. The resultant scattering integrals are combined in a single expression by using key formulas, defined for the perfect electromagnetic conductor and absorbing surfaces. The diffracted and geometric optics fields are obtained by the asymptotic evaluation of the scattering integral for large values of the wave-number. The behaviors of the derived field expressions are analyzed numerically. © 2021, Advanced Electromagnetics. All rights reserved.Article Modified Theory of Physical Optics Solution of Impedance Half Plane Problem(Ieee-inst Electrical Electronics Engineers inc, 2006) Umul, Yusuf Z.; Umul, Yusuf Ziya; 42699The scattering of electric polarized plane waves from an impedance half plane problem is examined by the method of modified theory of physical optics (MTPO). Two integrals, consisting of incident and reflected scattered fields, are obtained. These integrals are evaluated asymptotically by the methods of stationary phase and edge point. The obtained scattered fields are compared with the exact solution numerically.Editorial Reply to the "a comment on "the photon momentum"(Elsevier Gmbh, Urban & Fischer verlag, 2014) Umul, Yusuf Z.; Umul, Yusuf Ziya; 42699Article Scattering of a Gaussian beam by an impedance half-plane(Optical Soc Amer, 2007) Umul, Yusuf Z.; Umul, Yusuf Ziya; 42699The diffraction of a Gaussian beam by an impedance half-plane is studied through the method of the modified theory of physical optics. An electric line source, which is defined in the complex space, is used to represent the Gaussian beam. The uniform evaluation of the diffraction integral is performed and the scattering patterns of the field are investigated for various numerical parameters of the incident wave. (c) 2007 Optical Society of America.Article Scattering of waves by a half-screen with different face impedances: closed form series solution(Taylor & Francis Ltd, 2013) Umul, Yusuf Z.; Umul, Yusuf Ziya; 42699A novel series solution is obtained for the scattering problem of waves by a half-plane with different face impedances. The impedance condition is expressed in terms of the sum of Dirichlet and Neumann conditions, multiplied by appropriate coefficients. The scattering problem of plane waves by an interface between two half-planes with different impedances is also investigated. The results are compared with the literature, numerically.Article The physical optics integral on the scatterer's unlit surface(Elsevier Gmbh, 2014) Umul, Yusuf Z.; Umul, Yusuf Ziya; 42699The scattering integrals of the modified theory of physical optics are redefined according to the illuminated and unlit surfaces of the scattering object. With this aim the canonical problem of wedge diffraction is taken into account. It is shown that the new scattering integral contain two geometrical optics and diffracted fields. One of the geometrical optics waves is the reflected field component that propagates in the real space. The other one transmits to an imaginary space through the scattering surface and does not have any influence in the real space. The diffracted waves exist in the real space and satisfy the related boundary condition on the scattering surfaces. The resultant field expressions are compared with the exact series solution of the problem numerically. (C) 2014 Elsevier GmbH. All rights reserved.Correction Uniform Theory for the Diffraction of Evanescent Plane Waves: Publisher's Note (Vol 24, Pg 2426, 2007)(Optical Soc Amer, 2007) Umul, Yusuf Z.
