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Unformatted text preview: The Huygens-Fresnel Principle In 1609 Christian Huygens proposed that in order to predict how a wavefront will propagate: Every point on a propagating wavefront serves as the source of spherical secondary wavelets, such that the wavefront at a later time is the envelope of these wavefronts. This principle was extended by Fresnel to take into account the wavelength of the waves. The Huygens- Fresnel principle states: Every unobstructed point of a wavefront is a source of spherical secondary wavelets with the same frequency as that of the primary wave. The amplitude of the resultant wave at any forward point is the superposition of these wavelets (considering their amplitudes and relative phases). The application of this principle is to waves near an aperture is shown in . Figure %: Huygen's principle applied to wide and narrow apertures. As can be seen from this diagram, if the wavelength of the wave is large compared to the width of the aperture, the waves will spread out at large angles into the 'shadow' region behind the...
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This note was uploaded on 02/09/2012 for the course PHY PHY2053 taught by Professor Davidjudd during the Fall '10 term at Broward College.
- Fall '10