WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
Browse
19 results
Search Results
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.Article Citation - WoS: 34Citation - Scopus: 37Diffraction of Evanescent Plane Waves by a Resistive Half-Plane(Optical Soc Amer, 2007) Umul, Yusuf Z.Diffraction 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 Citation - WoS: 19Citation - Scopus: 19Scattering of a Gaussian Beam by an Impedance Half-Plane(Optical Soc Amer, 2007) Umul, Yusuf Z.The 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 Citation - WoS: 1Citation - Scopus: 1Interaction of Electromagnetic Waves With a Resistive Half-Plane(Springer France, 2016) Umul, Yusuf Z.The interaction process of electromagnetic waves by a resistive half-plane is investigated. The scattered geometrical optics fields are obtained by subtracting the incident field from the total geometrical optics waves. The physical optics integral of the scattered waves is derived with the aid of the scattered geometrical optics fields. The edge diffracted waves are derived from the physical optics integral by the edge point technique. A correction field is added to the diffracted fields in order to obtain a solution that satisfies the resistive boundary conditions on the surface of the half-screen. The uniform diffracted fields are expressed in terms of the Fresnel function and the resultant field representations are compared with the literature numerically.Article Citation - WoS: 4Citation - Scopus: 4Fictitious Diffracted Waves in the Diffraction Theory of Kirchhoff(Optical Soc Amer, 2010) Umul, Yusuf Z.The diffraction theory of Kirchhoff is applied to the semi-infinite aperture of a black half-screen. The derivative of the spherical Green's function is taken into account without any approximation. The uniformly evaluated scattering integral is compared with the physical optics solution. It is shown that the non-omitted term causes the existence of fictitious diffracted waves. (C) 2009 Optical Society of AmericaArticle Citation - WoS: 7Citation - Scopus: 8Apertured Paraxial Bessel Beams(Optical Soc Amer, 2010) Umul, Yusuf Z.The paraxial Bessel beam is obtained by applying an approximation in the wavenumbers. The scattering of the beams by a circular aperture in an absorbing screen is investigated. The scattered fields are expressed in terms of the Fresnel integrals by evaluating the Kirchhoff diffraction integral in the paraxial approximation. The results are examined numerically. (C) 2010 Optical Society of AmericaArticle Citation - WoS: 11Citation - Scopus: 11Uniform Boundary Diffraction Wave Theory of Rubinowicz(Optical Soc Amer, 2010) Umul, Yusuf Z.Rubinowicz introduced a uniform asymptotic evaluation of the boundary diffraction wave at the transition region [Ann. Phys. (Leipzig) 378, 339 (1924)]. The uniform theory of Rubinowicz is generalized for the improved integrals of the boundary diffraction wave. The technique is applied to the scattering problem of plane waves by an impedance half-plane, and the diffracted waves are examined numerically. (C) 2010 Optical Society of AmericaArticle Citation - WoS: 11Citation - Scopus: 11Effect of the Shadow Geometry in Wedge Diffraction(Optica Publishing Group, 2009) Umul, Yusuf Z.The surface integrals of the modified theory of physical optics are divided into two parts for diffraction by a wedge. Each integral represents the incident or reflected field scattered by one of the faces of the wedge. The results are investigated numerically and compared with the uniform theory of diffraction. (C) 2009 Optical Society of AmericaArticle Citation - WoS: 25Citation - Scopus: 6Improved Equivalent Source Theory(Optical Soc Amer, 2009) Umul, Yusuf Z.The equivalent source theorem, which is an important technique in the study of radiation and scattering by apertures, is improved by using the two axioms of the modified theory of physical optics. The method is applied to the problem of radiation of electromagnetic waves by a parallel plate waveguide. The results are investigated numerically. (C) 2009 Optical Society of AmericaArticle Citation - WoS: 15Citation - Scopus: 15Effect of the Shadow Geometry on Diffraction(Optical Soc Amer, 2008) Umul, Yusuf Z.The effect of the scatterer surface on the shadow region is examined by using the surface integrals of the modified theory of physical optics. It is shown that the shadow geometry has a considerable effect on the structure of the edge diffracted waves. The diffracted fields for the illuminated and shadowed surface of a half-plane are evaluated in terms of Fresnel integrals and plotted numerically. (C) 2008 Optical Society of America