Edge-On Diffraction of a Gaussian Laser Beam by a Semi-Infinite Plane

Abstract

A He-Ne laser beam is used here to illuminate a razor blade at edge-on incidence. The incident light is found to be scattered into a single straight cone of circular cross section. The tip of this cone of diffracted light lies at the point of incidence, its axis coincides with the prolongation of the razor edge, and its halfangle is equal to the angle of incidence. Such cones formed by a family of diffracted rays are basic to the so-called geometrical theory of diffraction. However, the properties and geometrical laws associated with the diffracted rays are derived analytically here by application of the boundary diffraction wave theory. The experimental results are in agreement with theoretical predictions.

Uniform Scattered Fields of the Extended Theory of Boundary Diffraction Wave for Pec Surfaces

“…by considering Eqs. (10) and (15). Hence, the diffracted field integral can be found by utilizing Eqs.…”

“…TBDW can be easily applied to various diffraction problems, but it does not give satisfactory solutions for diffracted fields from PEC and impedance surfaces, since the theory is solely based on opaque screen. TBDW was studied by Otis and Lit [10] for the problem of diffracted Gaussian laser beams from the edge of the half plane. The problem of the diffraction from the opaque half plane was studied for normal and oblique incidence with TBDW approach in [11,12].…”

“…In this paper, the modified vector potential of TBDW is defined by using a different approach other than methods available in the literature [10][11][12][13][14]. Here, this vector potential is applied to the Helmholtz-Kirchhoff integral, and TBDW is extended for PEC surfaces.…”

Beam diffraction by a resistive half-plane

“…Although a good match is seen in the shadow region, the theoretical plot does not show the interference fringes that had to be seen in the illuminated region. Otis and co-workers used the boundary diffraction wave theory in order to examine the diffraction of a Gaussian beam [6][7][8].…”

Scattering From Perfectly Magnetic Conducting Surfaces: The Extended Theory of Boundary Diffraction Wave Approach

“…TBDW method has been applied to diffraction problems. Otis and Lit were investigated diffraction of a Gaussian laser beam from the edge of an opaque half plane by using the TBDW [9]. The uniform diffracted fields from an opaque half plane were examined for normal and oblique incidence with TBDW approach [10,11].…”