Diffraction from a wedge - TMz case [FDTD simulation]

Here, we demonstrate the diffraction from a wedge when a plane wave with electric field component normal to the surface is impinging on it. The wedge corner acts as a secondary source to generate cylindrically propagating waves which are clearly seen when the scattered field plots on the right is analyzed. The left side of the animation shows the total field where both the scattered and incident fields are plotted together.





Beugung, Difracción, Diffrazione, Kırınım, 回折, Дифракция, Diffractie, Difração, 衍射, Dyfrakcja, Diffraktion, Interferenz, Interferencia

Diffraction from Double Slits (Young's Double Slits)

The double slit diffraction is illustrated via the use of finite-difference time-domain (FDTD) simulation. Two sets of double slits with different widths and a single slit - for comparison - are illuminated by normally incident plane waves. When the impinging plane waves reach the slits, they are diffracted into a series of circular waves. In the case of double slits, constructive and destructive interferences create dark (null) and bright spots. Diffraction is basically the phenomenon involving the bending of waves around obstacles and the spreading out of the waves past small openings. Huygen's Principle states that every point on a wavefront acts as a source of tiny wavelets moving forward with the same speed as the wave and the wavefront is the surface tangent to these wavelets. 

Keywords:

Beugung, Difracción, Diffrazione, Kırınım, 回折, Дифракция, Diffractie, Difração, 衍射, Dyfrakcja, Diffraktion, Interferenz, Interferencia, Young's slit,

Ground Penetrating Radar (GPR) B-Scan Collection (FDTD Animation )

Here, B-scan data collection of a simple ground penetrating radar (GPR) is animated through the use of Finite-difference time-domain (FDTD) method. The upper part of the animation shows the 2D spatial propagation of the short pulse transmitted from the antenna at different spatial locations. The transmitting antenna shoots a short electromagnetic pulse (with a central frequency of 600 MHz) into the subsurface where the relative dielectric permittivity is 4. The short pulse is reflected from the air-soil interface and then from the target embedded in the subsurface. Then, the scattered signals are recorded by the same antenna in the receiving mode. The lower part of the animation corresponds to the received signals (A-scan) at the same antenna for each of the positions. This constitutes the so-called B-scan data collection.

Diffraction from a Single Slit (FDTD Animation)

The single slit diffraction is illustrated via the use of finite-difference time-domain (FDTD) simulation in which slits with various widths are illuminated by electromagnetic plane waves at a single frequency. When the impinging plane waves reach the slits, they are diffracted into a series of circular waves and the emerging wavefront from the slits become cylindrical waves.

Diffraction is basically the phenomenon involving the bending of waves around obstacles and the spreading out of the waves past small openings. Huygen's Principle states that every point on a wavefront acts as a source of tiny wavelets moving forward with the same speed as the wave and the wavefront is the surface tangent to these wavelets.