The Diffraction of Sound Waves. Diffraction Gratings.

Diffraction grating, component of optical devices consisting of a surface ruled with close, equidistant, and parallel lines for the purpose of resolving light into spectra. What is Diffraction? The fact that diffraction is more pronounced with longer wavelengths implies that you can hear low frequencies around obstacles better than high frequencies, as illustrated by the example of a marching band on the street. Patrick Agyapong, IUB, Spring 2005 Diffraction Gratings: Theory and Applications 4 Planar Diffraction Gratings There are basically two modes of operation. 1. zBasically, a diffraction grating performs a Fourier Transform, separating a waveform in the time domain into a number of waveforms in the frequency domain. Diffraction occurs when the wavelength of a wave is of a similar size to an obstacle or a gap in a barrier. Single-slit diffraction is useful when it is known ahead of time that the light (or another type of wave) in the experiment is monochromatic and coherent. Any type of wave can be diffracted. A diffracted wave will "spread out". Diffraction in such cases helps the sound to "bend around" the obstacles. When does Diffraction happen? After diffraction, a wave will have the same speed, frequency and wavelength. A grating is said to be a transmission or reflection grating according to whether it is transparent or mirrored—that is, whether it is ruled on glass or on a thin metal film deposited on a glass blank. Wall Street business magnate Stephen Chu, winner of the Strathmore’s Who’s Who Registry honoring the most successful business tycoons in the world, says the "Demolisher" Betting System lived up exactly to its billing!